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SECTION 1 GENERAL INFORMATION

GENERAL INFORMATION

1.1 SCOPE OF MANUAL

This service manual contains installation, opera­tion, programming, alignment, and service informa­tion for the E.F. Johnson Multi-Net® 8560-8568
Viking CK and 8588-8588 Viking CM transceivers.
For information on servicing the LTR® version of
these transceivers (Viking CL), refer to Service
Manual Part No. 001-8560-005.

1.2 EQUIPMENT DESCRIPTION

1.2.1 GENERAL

The available Multi-Net transceivers and the
main features of each are shown in Table 1-1. The
8560-8566 and 8585-8588 models covered by this
manual operate on the 800 MHz frequencies from
806-825 MHz (mobile transmit). The receive channels
are 45 MHz above these frequencies from 851-870
MHz. Channel spacing is 25 kHz and maximum devi­ation is 5 kHz. With NPSPAC models (see Section

1.2.6), channel spacing is 12.5 kHz and maximum
deviation is 4 kHz.

These transceivers can be programmed with up to
14 systems. Each Multi-Net system can be
programmed with up to 11 groups, and each LTR and
conventional system can be programmed with up to 10
groups.

1.2.2 8560-8568 MODELS

The 8560 is the base 1-watt model, and the 8565
is the base high power model. Each is available with a
DTMF keypad for making telephone calls (see photos
on front cover). The 8560 power output is fixed, and
the 8565 has a user selectable power output of 1.8 and

3.0 watts (see Section 1.2.4 for more information).

The other 856x models are intrinsically safe and
NPSPAC versions of these transceivers. All 8560­8568 models operate the same because they have the
same software. These transceivers do not have a quick
select switch or the other operation enhancements of
the 8585-8588.

1.2.3 8585-8588 MODELS

The 8585-8588 models are enhanced versions of
the 8565-8568. These models have a 16-position
quick select switch on the top panel which allows up
to 16 preprogrammed system/groups to be quickly
selected. In addition, they have enhanced software
which allows the selected system or group to be
decreased as well as increased. Also, a special menu
can be selected for controlling high and low power,
keypad disable, and clear-to-talk tone loudness. Other
hardware differences between these and the 8560­8568 models are the top and front panels and logic
board. Each of these models are also available with a
DTMF keypad for making telephone calls.

1.2.4 VIKING CK AND CM MODELS

In mid 1994, Viking CK and CM models were
introduced. The CK designation applies to the 8560­8568, and the CM designation applies to the 8585-

8588. The main change that occurred with these
models is that the power output of the standard and
NPSPAC models increased from 2.5 watts to 3.0
watts. The power output of the 1-watt models is
unchanged as is the 2.5-watt power output of the high
power intrinsically safe models.

1.2.5 INTRINSICALLY SAFE MODELS

The intrinsically safe versions meet Factory
Mutual standards for operation in certain flammable
atmospheres. This manual covers servicing of both
types of transceivers. Refer to Section 1.10 for impor­tant information on servicing intrinsically safe models.

1.2.6 NPSPAC MODELS

The NPSPAC transceivers meet the stricter speci­fications established by NPSPAC (National Public
Safety Panel Advisory Committee) for operation on
the public safety frequencies from 821-824 and 866­869 MHz. The only differences between these and
non-NPSPAC models are the TCXO (a 1.5 PPM
version is used), receiver ceramic filter Z522, and the
alignment procedure (deviation is less).

1-1

Revised February 1997

Part No. 001-8560-381

GENERAL INFORMATION

Table 1-1 EFJOHNSON MULTI-NET TRANSCEIVERS

Transceiver

8160 Avr SK 800 Handheld 1/3W 14/11 Yes Small size, Qk Sel Sw
8161 Avr SK 800 Handheld 1/2W 14/11 Yes Small size, Qk Sel Sw, NPSPAC
8190 Vik CR 800 Handheld 0.6/1W 32/11 Talk-Around N/A Full duplex cellular style
8560 Vik CK 800 Handheld 1W 14/11 Yes Standard Model
8561 Vik CK 800 Handheld 1W 14/11 Yes Intrinsically Safe
8562 Vik CK 800 Handheld 1W 14/11 Yes NPSPAC
8563 Vik CK 800 Handheld 1W 14/11 Yes Intrin Safe, NPSPAC
8565 Vik CK 800 Handheld 1.8/3.0W 14/11 Yes High Power
8566 Vik CK 800 Handheld 1.5/2.5W 14/11 Yes High Power, Intrin Safe
8567 Vik CK 800 Handheld 1.8/3.0W 14/11 Yes High Power, NPSPAC
8568 Vik CK 800 Handheld 1.5/2.5W 14/11 Yes Hi Pwr, Intrin Safe, NPSPAC
8570 Vik CK 900 Handheld 1W 14/11 Yes Standard Model
8571 Vik CK 900 Handheld 1W 14/11 Yes Intrinsically Safe
8585 Vik CM 800 Handheld 1.8/3.0W 14/11 Yes Hi Pwr, Quick Select Switch
8586 Vik CM 800 Handheld 1.5/2.5W 14/11 Yes Hi Pwr, Qk Sel Sw, Intrin Safe
8587 Vik CM 800 Handheld 1.8/3.0W 14/11 Yes Hi Pwr, Qk Sel Sw, NPSPAC
8588 Vik CM 800 Handheld 1.5/2.5W 14/11 Yes Hi Pwr, Qk Sel Sw, Intrin Safe,

8590 Vik CM 900 Handheld 1W 14/11 Yes Quick Select Switch
8591 Vik CM 900 Handheld 1W 14/11 Yes Qk Sel Sw, Intrin Safe

Freq

(MHz)

Typ e

Power

Output

System/

Groups [1]

M-Net/LTR/Conv

Operation; Conv

Talk-Around

Special Features

NPSPAC

8605 800 Frt Mount 15W 16/11 Yes Low Power
8606 800 Frt Mount 15W 16/11 Yes Low Power, NPSPAC
8615 800 Frt Mount 35W 16/11 Yes High Power
8616 800 Frt Mount 35W 16/11 Yes High Power, NPSPAC
8620 800 Rem Mount 35W 16/11 Yes High Power, Remote Mount
8621 800 Rem Mount 35W 16/11 Yes High Pwr, Rem Mt, NPSPAC
8622 800 Rem Mount 12W 16/11 Talk-Around N/A Full Duplex
8655 900 Frt Mount 30W 16/11 Yes High Power

9753 Sum DM 800 Frt Mount 15W 32/11 Yes Hi Spec/Full Feature, Low Pwr
9754 Sum DM 800 Rem Mount 15W 32/11 Yes Hi Spec/Full Feature, Low Pwr
9755 Sum DM 800 Frt Mount 35W 32/11 Yes Hi Spec/Full Feature, Hi Pwr
9756 Sum DM 800 Rem Mount 35W 32/11 Yes Hi Spec/Full Feature, Hi Pwr
9773 Sum DM 900 Frt Mount 15W 32/11 Yes Hi Spec/Full Feature, Low Pwr
9774 Sum DM 900 Rem Mount 15W 32/11 Yes Hi Spec/Full Feature, Low Pwr
9775 Sum DM 900 Frt Mount 30W 32/11 Yes Hi Spec/Full Feature, Hi Pwr
9776 Sum DM 900 Rem Mount 30W 32/11 Yes Hi Spec/Full Feature, Hi Pwr
[1] All models have up to 11 groups per Multi-Net system and up to 10 groups per LTR or conventional system. The 97xx
transceivers can be programmed with more systems if less than the maximum number of groups are programmed (see Section

1.2.3).

1.2.7 VOICE ENCRYPTION

This feature prevents conversations from being moni­tored by casual eavesdropping or analog scanners.

Voice encryption is available as a factory

installed option on 8585-8588 transceivers (see

Refer to Section 2.3.18 for more information on
encryption.

Section 1.4). It is not available as a field-installed kit.

Revised February 1997
Part No. 001-8560-381

1-2

GENERAL INFORMATION

1.2.8 MISCELLANEOUS INFORMATION

The 856x and 857x transceivers shown in Table
1-1 are available in Multi-Net and LTR versions, and
the 858x and 859x transceivers are available in only
the Multi-Net version. The difference between the
Multi-Net and LTR versions of the 856x/857x is the
operating software in the microprocessor.

The Multi-Net models can be programmed for
Multi-Net, LTR, and conventional operation, and the
LTR models can be programmed for only LTR and
conventional operation. Up to 14 systems can be
programmed, and each Multi-Net system can have up
to 11 groups, and each LTR and conventional system
up to 10 groups.

Like other E.F. Johnson Multi-Net and LTR trans­ceivers, these are digitally synthesized and logic
controlled. In the Multi-Net and LTR modes, all the
user has to do to make a call is select the desired
system and group and press the push-to-talk switch. If
a busy or out-of-range condition is not indicated by
special tones, the path to the other party is complete
and speaking can begin. Channel selection, monitoring
before transmitting, and squelch control are all
performed by the logic.

Programming is performed using a dealer

supplied IBM® PC or compatible computer and
EFJohnson programming software. No PROMs are
ever needed because the personality information is
stored by a reprogrammable memory device called an
EEPROM. Refer to Section 4 for more programming
information.

An 85xx handheld transceiver can be converted
to mobile operation using the optional Vehicular
Adapter. Plugging the transceiver into this adapter
connects it to the mobile antenna, microphone, and
speaker. The Remote Control Unit can also be used in
this application if desired.

1.3 PART NUMBER BREAKDOWN

The following is a breakdown of the part number

used to identify this transceiver:

NOTE: Encryption is available for 8585-8588 models
only (see Section 1.2.7).

242 – 8 5 x x – x 1

See Table 1-1

0 = Std w/o accessories
1 = Std w/ant, bat, belt clip
2 = Std w/o access, w/encrypt
3 = Std w/ant, bat, clip, encryp
4 = 3W w/o accessories
5 = 3W w/ant, bat, belt clip
6 = 3W w/o access, w/encryp
7 = 3W w/ant, bat, clip, encryp

1 = LTR
2 = LTR w/DTMF
5 = Multi-Net
6 = Multi-Net w/DTMF

x

1.4 TRANSCEIVER IDENTIFICATION

The transceiver identification number is printed
on a label that is affixed to the back cover. The identi­fication number used with Viking CK and CM models
is shown below and has an additional digit after the
model number. This digit is used to identify the trans­ceiver as a Multi-Net or LTR model and also if it has
standard (1 or 2.5W) or 3W power output. For
example, a Viking CK 8566 has a “5” because it is 2.5
watts, and a Viking CK 8565 has a “6” because it is 3
watts.

Model

Revision

Letter

Manufacture

Date

PlantFrom P.N.

Warranty

Number

The optional Vehicular Charger accessory is a
low-cost alternative to the Vehicular Adapter. It
provides only trickle charging and does not allow the
use of the Remote Control Unit. Refer to Section 5 for
more information on these accessories.

85xx x A 23 7 A 12345

1 = LTR std
2 = LTR 3W

Last Digit of Year

5 = M-Net std
6 = M-Net 3W

1-3

Week No. of Year

Revised February 1997

Part No. 001-8560-381

A = Waseca

GENERAL INFORMATION

85xx A 23 7 A 12345

Model

Revision

Letter

Manufacture

Date

Warranty

Number

Month or Week

Last Digit of Year

A = Waseca

PlantFrom P.N.

The following information is contained in
numbers used with most earlier non-Viking CK/CM
models. For the manufacture date, the 8560-8563 use
month/year and the 8565-8568 use week/year.

1.5 ACCESSORIES

The accessories available for this transceiver are
listed in Table 1-2. A brief description of several of
these accessories follows.

Battery Chargers - The -400/-476 chargers utilize

∆T/∆t charging technology. Refer to Sections 5.1 and

5.2 for information on battery packs and chargers.

Vehicular Adapter and Remote Control Unit-
Allow transceiver to be converted to mobile use. Refer
to Section 5 for more information.

• Clip attachment to the belt without a D-swivel or

leather case. This requires the –126 or –128 belt
clip. A belt clip is included in the standard package.

Programming Accessories - Refer to Section 4 for
information on transceiver programming.

Extension Test Cable and Accessory Connector
Kit- The extension test cable is used to operate the

transceiver with the front cover removed. The acces­sory connector kit contains the parts required to make
a test cable or some other type of cable that plugs into
the accessory connector. This particular kit does not
include the magnets that may be required for the LTR
5876 transceiver. Use Kit, Part No. 023-5810-110, if
those magnets are required.

Table 1-2 856x/858x Accessories

Accessory Part No.

Battery Packs

7.5V 1400 mAH (standard) 587-8565-171

7.5V 1400 mAH (intrinsically safe) 587-8565-162

Antenna, Flexible

1/4-wave 501-0105-012

1/2-wave 501-0105-013

Microphones, Speaker, and Adapters - The speaker­microphones are equipped with a 360

° swivel clip for

attachment to the collar or lapel. They also have an
earphone connector. The earphone and antenna
adapters allow an earphone or external antenna to be
connected to the accessory connector. The antenna
adapter includes a 6-foot RG-58 cable with a female
BNC connector. The transceiver automatically
switches to the external device when these adapters
are used.

Carrying Accessories - The carrying accessories
listed allow the transceiver to be carried in the
following ways:

• D-swivel attachment to the belt without a leather

case. The –130 belt loop and –121 transceiver
attachments are used.

• D-swivel attachment to the belt or chest with the

–125 leather case. The –130 belt loop is used to
attach this case to the belt, or the –004 shoulder
strap is used to attach it to the chest.

Battery Chargers

Five-Unit Rapid 239-5800-400

Single-Unit Rapid (base only) 239-5800-476

120 VAC power supply for -476 base 585-4001-101

240 VAC power supply for -476 base 585-4001-102

Trickle (100 mA) transformer 563-0001-003

Base for trickle charger 239-5800-371

Vehicular Adapter* 239-5810-500

Remote Control Unit, Multi-Net* 250-8610-506

Vehicular Charger* 239-5810-811

Speaker-Microphone, w/ant connector 589-0015-015

Speaker-Microphone, w/int amp 589-0015-020

Earphone for above speaker-mics 250-0881-003

Earphone (plugs into accessory conn.) 250-5810-816

External Antenna Adapter Cable 250-5810-813

Earphone Adapter, submin jack 250-5810-818

Earphone for above adapter, straight 250-0881-001

Earphone for above adapter, right angle 250-0881-002

Revised February 1997
Part No. 001-8560-381

1-4

GENERAL INFORMATION

Table 1-2 856x/858x Accessories (Continued)

Accessory Part No.

Dual earpiece headset w/mic
(following cable also required)

Belt mount PTT sw and interface cable 589-9006-022

Carrying Accessories

Leather belt loop with D-swivel 023-8790-130

Leather case with D-swivel 023-8560-125

Shoulder strap 508-4009-004

Perimeter strap 508-4011-410

D-Swivel attachment for transceiver 250-5810-121

(if -125 case is not used)

Belt clip for transceiver (if D-swivel

and leather case are not used)

Metal spring type 250-5810-126

Plastic press type 250-5810-128

Programming Accessories

Remote Prog Interface (RPI) 023-9800-000

RPI Interface Cable (85xx) 023-5810-011

RPI Interface Cable (Control Unit) 597-2002-200

Replication Cable 023-5810-013

Cable, RPI to computer 6’ DB9M-DB9F 597-5900-002

Cable, RPI to computer 6’ DB25 M-F 023-5800-017

Cable, RPI to computer 6’ DB25M-DB9F 597-0005-057

Programming Software, Transceiver

and Remote Control Unit

IBM 5.25" Disk 023-9998-191

IBM 3.5" Disk 023-9998-192

Star washer, unprogrammed
(see Section 1.12)

Extension Test Cable 023-8560-910

Accessory Connector Kit 023-5810-109

SMA-BNC F-F adapter 515-3102-050

* Refer to Tables 5-1 and 5-2 for additional vehicle adapter
accessories.

589-9006-021

015-0900-305

contacted for Warranty Service Reports, claim forms,
or any other questions concerning warranties or
warranty service.

1.7 FACTORY CUSTOMER SERVICE

The Customer Service Department of the E.F.
Johnson Company provides customer assistance on
technical problems and the availability of local and
factory repair facilities. Regular Customer Service
hours are 7:30 AM. - 5:30 PM. Central Time,
Monday - Friday. The Customer Service Department
can be reached using one of the following telephone
numbers:

Toll-Free: [phone]

(From within continental United States only)

International: [phone]

FAX: [phone]

E-Mail: First Initial/Last [e-mail]

(You need to know the name of the person you want to
reach. Example: [e-mail])

NOTE: Emergency 24-hour technical support is also
available at the 800 and preceding numbers during off
hours, holidays, and weekends.

When your call is answered at the E.F. Johnson
Company, you will hear a brief message informing
you of numbers that can be entered to reach various
departments. This number may be entered during or
after the message using a tone-type telephone. If you
have a pulse-type telephone, wait until the message is
finished and an operator will come on the line to assist
you. When you enter some numbers, another number
is requested to further categorize the type of informa­tion you need.

1.6 PRODUCT WARRANTY

The warranty statement for this transceiver is
available from your product supplier or from the
Warranty Department, E.F. Johnson Company, 299
Johnson Avenue, P.O. Box 1249, Waseca, MN 56093-

0514. This information may also be requested from the
Warranty Department by phone as described in
Section 1.7. The Warranty Department may also be

You may also contact the Customer Service
Department by mail. Please include all information
that may be helpful in solving your problem. The
mailing address is as follows:

E.F. Johnson Company

Customer Service Department

299 Johnson Avenue

P.O. Box 1249

Waseca, MN 56093-0514

Revised February 1997

1-5

Part No. 001-8560-381

GENERAL INFORMATION

1.8 FACTORY RETURNS

Repair service is normally available through local
authorized E.F. Johnson Land Mobile Radio Service
Centers. If local service is not available, the equipment
can be returned to the factory for repair. However, it is
recommended that you contact the Customer Service
Department before returning equipment because a
service representative may be able to suggest a solu­tion to the problem so that return of the equipment
would not be necessary.

Be sure to fill out a Factory Repair Request Form
#271 for each unit to be repaired, whether it is in or
out of warranty. These forms are available free of
charge by calling Customer Service (see Section 1.7)
or by requesting them when you send a unit in for
repair. Clearly describe the difficulty experienced in
the space provided and also note any prior physical
damage to the equipment. Then include a form in the
shipping container with each unit. Your telephone
number and contact name are important because there
are times when the technicians have specific questions
that need to be answered in order to completely iden­tify and repair a problem.

When returning equipment for repair, it is also a
good idea to use a PO number or some other reference
number on your paperwork in case you need to call the
repair lab about your unit. These numbers are refer­enced on the repair order and it makes it easier and
faster to locate your unit in the lab.

Johnson dealers also need to give their account
number. If there is uncertainty about the part number,
include the designator (C512, for example) and the
model number of the equipment the part is from.

You may also send your order by mail or FAX.
The mailing address is as follows and the FAX number
is shown in Section 1.7.

E.F. Johnson Company

Service Parts Department

299 Johnson Avenue

P.O. Box 1249

Waseca, MN 56093-0514

1.10 INTRINSICALLY SAFE INFORMATION

1.10.1 INTRODUCTION

The 8561, 8563, 8566, 8568, 8586, and 8588
transceivers have been approved by the Factory Mu­tual Research Corporation for operation in certain
flammable atmospheres. The specific atmospheres in
which operation is approved are shown in Section

1.10.5 and also on the label on the back cover of the
transceiver.

WARN I NG

When servicing an intrinsically safe transceiver, the
following rules must be followed to maintain intrinsic
safety:

Return Authorization (RA) numbers are not
necessary unless you have been given one by the Field
Service Department. RA numbers are required for
exchange units or if the Field Service Department
wants to be aware of a specific problem. If you have
been given an RA number, reference this number on
the Factory Repair Request Form sent with the unit.
The repair lab will then contact the Field Service
Department when the unit arrives.

1.9 REPLACEMENT PARTS

E.F. Johnson replacement parts can be ordered
directly from the Service Parts Department. To order
parts by phone, dial the toll-free number as described
in Section 1.7. When ordering, please supply the part
number and quantity of each part ordered. E.F.

Revised February 1997
Part No. 001-8560-381

• Service can be provided only by the factory or by

service centers specifically authorized by the
Factory Mutual Research Corporation to service
E.F. Johnson intrinsically safe transceivers. Contact
Factory Mutual at the following address for infor­mation concerning their auditing procedure. Contact
the E.F. Johnson Customer Service Department as
described in Section 1.7 if you have questions.

Factory Mutual Research Corporation
1151 Boston-Providence Turnpike
P.O. Box 9102
Norwood, Massachusetts 02062
Phone: [phone]

• Replace the battery pack only with Intrinsically Safe

Battery Pack, Part No.587-8560-160 (1000 mAH)

1-6

GENERAL INFORMATION

or 587-8565-162 (1400 mAH). The 1000 mAH pack
cannot be used with 8565-8588 transceivers.

• Do not make any modifications to the circuitry.

• When replacing a part, use only the exact replace-

ment part listed in the service manual parts list.

• Do not install any accessory that is not specifically

approved for use in intrinsically safe 85xx models.

1.10.2 DEFINITIONS

Intrinsically Safe - This is a fire rating given to these
transceivers by the Factory Mutual Research Corpora­tion. When electrical equipment is given this rating,
the equipment is considered incapable of releasing
sufficient electrical and thermal energy under normal
operation or specified fault conditions per the testing
standard to cause ignition of a specific flammable or
combustible atmosphere in its most easily ignited
concentration. In other words, this transceiver should
not cause a fire or explosion when used in certain
flammable atmospheres.

1.10.4 INTRINSICALLY SAFE AND NONINCENDIVE RATINGS

This transceiver is rated intrinsically safe for
some types of hazards and nonincendive for other
types of hazards. An intrinsically safe rating applies to
operation in Division 1 areas, and a nonincendive
rating applies to operation in Division 2 areas (see
next section). The difference between these ratings is
as follows:

The intrinsically safe rating is a higher rating
because more severe conditions must be met. To be
approved for this rating, the transceiver must not cause
ignition of a particular atmosphere if two of the faults
specified in the testing procedure occur. In other
words, it must be able to withstand two simultaneous
unrelated breakdowns without causing ignition. To
receive a nonincendive rating, the transceiver needs to
withstand only a single fault without causing ignition
of a particular atmosphere.

1.10.5 CLASSIFICATION OF HAZARDOUS

AREAS AND ATMOSPHERES

Fault - A defect or electrical breakdown of any
component, spacing, or insulation which alone or in
combination with other faults may adversely affect the
electrical or thermal characteristics of the intrinsically
safe circuit (for example, a shorted transistor).

1.10.3 POSSIBLE IGNITION SOURCES

When a transceiver is checked by Factory
Mutual, possible sources of ignition are checked.
These sources may be electrical (spark) or thermal
(heat). The following could be sources of spark
ignition:

• Discharge of a capacitive circuit by a fault such as a

short circuit.

• Interruption of an inductive circuit.

• Intermittent making or breaking of a resistive

circuit.

• Hot-wire fusing.

The following could be sources of thermal
ignition:

• Heating of a small-gauge wire or PC board trace.

• High surface temperature of components.

Introduction

The specific hazardous atmospheres and areas in
which this transceiver is approved for operation are as
follows. These descriptions are also indicated on the
label on the back panel of the transceiver. The mean­ings of these Class, Division, and Group designations
are as follows.

Intrinsically Safe - Class I and II, Division 1, Groups
C, D, E, F, and G.

Nonincendive - Class I, Division 2, Groups A, B, C,
and D.

Temperature Code - T4A (1000 mAH pack, Part No.
587-8560-160) or T3C (1400 mAH pack, Part No.
587-8565-162).

Atmosphere Classification (Class/Group)

For the purposes of testing and approval, various
atmospheric mixtures have been grouped on the basis
of their hazardous characteristics. Equipment is
approved for a class of material and also for the
specific gas, vapor, or dust in that class. Class I mate-

1-7

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Part No. 001-8560-381

GENERAL INFORMATION

rials include gases and vapors, Class II materials
include combustible dusts, and Class III materials
include ignitable fibers. The various classes and some
specific groups of gases in each are shown in Table 1-

3.

Table 1-3 Material Classification

Typical Hazard Group Class

Acetylene A I

Hydrogen B I

Ethylene, ethyl ether, cyclopropane C I

Gasoline, naphta, butane, propane,
alcohol, acetone, benzol, natural gas

Metal dust including aluminum,
magnesium, and their alloys

Carbon black, coal, or coke dust F II

Flour, starch, or grain dusts G II

Ignitable fibers/flyings such as rayon or
cotton

DI

EII

-III

Area Classification (Division)

Areas are either Division 1 or 2 as shown in
Table 1-4. Since a Division 1 area is considered the
most hazardous, a transceiver approved for a specific
Division 1 area can also be used in the same
Division 2 Class/Group.

Table 1-4 Area Classification

two remaining tabs on the star washer. To limit the
rotation of this switch to certain positions, a new star
washer (Part No. 015-0900-305) is required. One new
star washer is included with the transceiver. To
program this washer, proceed as follows:

1. Pull off the rubber knob cover and note the vertical
position of the knob on the shaft. Loosen the set
screw and remove the knob.

2. Place the new star washer over the shaft as shown
below (do not remove the spanner nut yet).

3. The tabs removed are opposite the positions to be
selected. Therefore, determine what numbers are
opposite and then mark the tabs between those
numbers. For example, to select positions 1-4, mark
the three tabs between 9 and 12.

4. Remove the marked tabs as shown below by
bending them sharply or cutting them off.

Division Area

1 An area where there is or could be an explosive

atmosphere most of the time in normal
operation.

2 An area where an explosive atmosphere exists

only as a result of a fault (something going
wrong).

1.11 PROGRAMMING QUICK SELECT SWITCH STOPS (858x ONLY)

There is a star washer under the quick select
switch knob of 858x transceivers that limits the rota­tion of the switch (see Figure 1-1). As received from
the factory, only the dot (

● ) position of this switch is

locked out. To also select that position, remove the

Revised February 1997
Part No. 001-8560-381

5. Remove the spanner nut and old star washer. Install
the new star washer. Make sure that the removed
tabs are opposite the numbers to be selected.

6. Replace the spanner nut, knob, and rubber knob
cover.

1-8

GENERAL INFORMATION

Figure 1-1 Quick Select Switch Exploded

View

1.12 INTERNET HOME PAGE

The E.F. Johnson Company has a home page on
the World Wide Web that can be accessed for informa­tion on such things as products, systems, and regula­tions. The address is http://www.efjohnson.com.

1-9

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Part No. 001-8560-381

GENERAL INFORMATION

MULTI-NET 8560-8566 AND 8585-8588 SPECIFICATIONS

The following are general specifications intended for use in testing and servicing this transceiver. For current
advertised specifications, refer to the specification sheet available from the Marketing Department. Specifications
are subject to change without notice.

GENERAL

Operating Mode Multi-Net and LTR (trunked); Conventional (non-trunked)
Frequency Range 806-825 MHz transmit, 851-870 MHz receive (standard)

851-870 MHz transmit (Conventional talk-around)
Systems Up to 14
Groups Up to 11 per system (Multi-Net)

Up to 10 per system (LTR and Conventional)
Channels Up to 10 per system, 140 total (Conventional)
Tx/Rx Separation 45 MHz (no separation in talk-around)
Channel Spacing 25 kHz (12.5 kHz NPSPAC
Channel Increment 12.5 kHz
Dimensions 5.90" (w/o bat), 8.31" (w/bat) H x 2.76" W x 1.70" D

15.0 cm (w/o bat), 21.1 cm (w/bat) H x 7.0 cm W x 4.3 cm D

Weight 15.0 oz (w/o bat), 24.7 oz. (w/ bat)

425 g (w/o bat), 700 g (w/bat)
Power Source 7.5 VDC (nominal) rechargeable Nickel-Cadmium batt pack
Compliance FCC Parts 15 and 90
Circuit Protection 4-ampere fuse on motherboard
Typical Battery Life, 5-5-90% duty cycle 8560-8563 - 11 hours (1000 mAH bat), 14 hours (1400 mAH bat)
(Transmit/Receive/Standby) 8565-8588 (2.5W) - 10.5 hrs @ 1.5 W, 9.0 hrs @ 2.5W (1400

mAH battery pack)

8565-8588 (3.0W) - 10.3 hrs @ 1.8W, 8.5 hrs @ 3.0W (1400

mAH battery pack)

RECEIVER

Sensitivity 0.35 µV (12 dB SINAD)
Selectivity

Standard 25 kHz –70 dB

NPSPAC 12.5 kHz –20 dB
Spurious and Harmonic Rejection –70 dB (60 dB 1st/2nd image)
Intermodulation –65 dB
Hum and Noise –40 dB (–30 NPSPAC)
Audio Output Power Internal Speaker - 0.5 watt (16-ohm load)

External Speaker - 0.125 watt (16-ohm load)

Audio Distortion Less than 5% at rated output at speaker outputs (slightly higher

at external speaker output of accessory connector)

Audio Response +2, –10 dB from 6 dB per octave pre-emphasis characteristic

from 300-3000 Hz

Channel Spread 19 MHz

Revised February 1997

1-10

Part No. 001-8560-381

GENERAL INFORMATION

Frequency Stability ± 2.5 PPM from –22 to +140 degrees F (–30 to +60 degrees C)

± 1.5 PPM (NPSPAC models)
Input Impedance 50 ohms
Current Drain Standby (squelched) - 60 mA maximum, 55 mA typical
Rated audio output - 250 mA maximum, 225 mA typical

TRANSMITTER

RF Power Output 8560-8563 - 1 watt standard, 0.8 watt talk-around
(see Section 1.2.4) 8565-8588 (2.5W) high pwr - 2.5W standard, 2.0 W talk-around

8565-8588 (2.5W) low power - –2.25 ±.75 dB of high pwr setting

(1.5 watt typical)

8565/67, 8585/87 (3.0W) high pwr - 3.0W std, 2.0 W talk-around

8565/67, 8585/87 (3.0W) low power - 1.8W typical

Spurious and Harmonic –55 dB (std), –47 dB (talk-around) FM Hum and Noise
Standard Models –40 dB (w/C-message weighting)
NPSPAC Models –34 dB
Audio Distortion 5% maximum at 1 kHz
Audio Frequency Response +1, –3 dB from a 6 dB per octave de-emphasis characteristic

from 300-3000 Hz
Audio Modulation 16KOF1D, 16KOF3E (standard)

14KOF1D, 14KOF3E (NPSPAC)
Channel Spread 19 MHz (806-825 and 851-870 MHz)
Frequency Stability ±2.5 PPM from -22 to +140 degrees F (–30 to +60 degrees C)

±1.5 PPM NPSPAC
Current Drain 8560-8563 - 700 mA maximum, 600 mA typical

8565-8588 (2.5W) - 1350 mA maximum low power (1.5W)

1850 mA maximum high power (2.5W)

8565-8588 (3.0W) - 1400 mA maximum low power (1.5W)

2000 mA maximum high power (2.5W)
Load Impedance 50 ohms
Duty Cycle (6-6-48 seconds) 10%
(Transmit/Receive/Standby)

Revised February 1997
Part No. 001-8560-381

1-11

GENERAL INFORMATION

Revised February 1997
Part No. 001-8560-381

1-12

MULTI-NET SYSTEM OVERVIEW

SECTION 2 MULTI-NET SYSTEM OVERVIEW

(UP TO 30 PER RNT)

MULTI-NET 856x/7x/8x/9x, 8605/15/22/55,

SUMMIT DM 975x/977x MOBILE TRANSCEIVERS

LTR 98xx, 8600/04, 856x/857x, 5876, 86xx,

VIKING GT/HT 965x/967x MOBILE TRANSCEIVERS

REPEATERS

MULTI-NET

LT R

AUDIO AND

DATA LINK

AUDIO AND

DATA LINK

OTHE R

RNT’S

AND

SYSTEMS

REMOTE NETWORK

TERMINAL (RNT)

PUBLIC

SWITCHED

TELEPHONE

NETWORK

(PSTN)

DISPATCHER CONSOLE

AUDIO AND

CONVENTIONAL 98xx, 5876, 71x6/718x

CONVENTIONAL

Figure 2-1 Multi-Net System Components

2.1 MULTI-NET SYSTEM COMPONENTS

NOTE: For more information on Multi-Net systems,
refer to the Multi-Net Application Note, Part No.
009-3039-003.

2.1.1 INTRODUCTION

The basic components of a Multi-Net system are
shown in Figure 2-1. Because of the built-in adapt­ability of a Multi-Net system, one can be designed to
meet the communication needs of almost any type of
user. The following are some operating features that a
Multi-Net system can provide:

1. Advanced features such as up to 8000 Unique ID

code, automatic mobile identification, and five

DATA LINK

SYSTEM MANAGEMENT MODULE

levels of priority access are available if Multi-Net
signaling is used.

2. Users of different types of radio equipment can talk
to each other. For example, a mobile operating on a
Multi-Net 800 MHz channel could talk to a mobile
operating on a conventional UHF channel.

3. Wide area radio coverage can be provided so that a
mobile could talk to another mobile that is using a
repeater that may be hundreds of miles away. That
repeater may be part of the same Multi-Net system
or another Multi-Net system. Phone lines or some
other type of link can be used to provide a commu­nication path.

USAGE ACCOUNTING SYSTEM

2-1

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Part No. 001-8560-381

MULTI-NET SYSTEM OVERVIEW

Multi-Net systems are not restricted to a certain
type of signaling. For example, an entire Multi-Net
system could be designed using conventional channels
which use tone or digitally controlled squelch. The
various types of signaling can also be mixed in a
system. For example, there could be ten channels
using Multi-Net signaling, ten channels using LTR
signaling, and ten channels using conventional
signaling. Your EFJohnson representative can provide
more information on the capabilities of Multi-Net
systems.

The following information describes the Multi­Net components shown in Figure 5-1.

2.1.2 MOBILE TRANSCEIVERS

The mobile and handheld transceivers used in a
Multi-Net system must be compatible with the type of
signaling being used (Multi-Net, LTR, or conven­tional) and also the frequency range of the system
(UHF, 800 or 900 MHz). All Multi-Net transceivers
are triple-mode which means that they can be
programmed for Multi-Net, LTR, and conventional
(non-trunked) operation. There are also many other
EFJohnson transceivers available that can be
programmed for LTR and/or conventional operation.

2.1.3 REPEATERS

The EFJohnson Summit® QX is used with UHF,
800, and 900 MHz systems. One repeater is required
for each RF channel. The Summit QX contains a
Multi-Net processor card which controls signaling on
that channel and also allows the RNT to control the
repeater. The specific card that is used is determined
by the type of signaling used (Multi-Net, LTR, or
conventional).

reprogramming of mobiles and disabling of lost or
stolen mobiles are also performed by the SMM.

A single RNT can control up to 30 repeaters
which is the maximum allowed by the FCC at one
site. The RNT is configured with one Channel Inter­face Module (CIM) for each repeater it controls and
an Intelligent Dispatch Module (IDM) for each
EFJohnson Dispatch Console. It also contains a Tele­phone Interface Module (TIM) for each telephone line
used for interconnect calls and other modules.

2.1.5 DISPATCH CONSOLES

One or more EFJohnson Dispatch Consoles or
other consoles can be connected to the RNT using
direct connection, phone lines, or other types of links.
Depending on the capabilities of the particular
console, the dispatcher can perform such functions as
placing calls to specific mobiles, placing calls to other
dispatchers, patching mobiles together so they can talk
to each other, and monitoring status messages from
mobiles.

2.1.6 PUBLIC SWITCHED TELEPHONE NET-

WORK (PSTN)

When telephone (interconnect) calls are placed
by transceivers, the RNT routes the call to the PSTN.
The specific transceivers which can place calls and
other interconnect parameters are controlled by the
system manager through the SMM and also by the
programming of the transceivers.

The option to route telephone calls through a
Private Automatic Branch Exchange (PABX) is avail­able. The calling features of the PABX can then be
utilized.

2.1.4 REMOTE NETWORK TERMINAL (RNT)

The RNT along with the SMM (System Manage-

ment Module) control the Multi-Net system.

The SMM is an IBM®

PC or compatible
computer that is running Multi-Net software. This
computer connects to the RNT and is used by the
system manager to control the system. The SMM also
continuously monitors RNT operation and maintains
usage information which can be monitored by the
Usage Accounting System. Such activities as dynamic

Revised February 1997
Part No. 001-8560-381

2.2 DEFINITIONS OF MULTI-NET TERMS

Conventional System - A type of radio system that is
licensed to operate on only a single channel. There is no
automatic access to several channels.

Home Repeater - All Multi-Net mobiles have one of
the site repeaters assigned as their “home” repeater.
When standard dispatch (group) calls are placed, the
home repeater and group ID code identify the mobile or
group of mobiles that receive the call.

2-2

MULTI-NET SYSTEM OVERVIEW

Logic Trunked Radio (LTR) - This popular
EFJohnson radio system provides the basis for the
Multi-Net radio system. Both LTR and Multi-Net sys­tems utilize a channel management concept called
trunking (see “Trunked Radio System” which follows).
Logic circuitry in the mobile transceivers and repeaters
controls trunking. It continually monitors the system
and generates data messages which update the mobiles
and repeaters as to which repeaters are free.

Mobile - This term refers to a transceiver mounted in a
vehicle but it can also be applied to other types of trans­ceivers because they all operate basically the same. The
other types of transceivers are handhelds and control
stations. A control station is essentially a mobile trans­ceiver used at a stationary location such as at an office
site.

Monitor Repeater - This is the repeater that a mobile
is currently monitoring for update messages. This re­peater may be either the mobile's home repeater or the
site status repeater. When a mobile is not receiving a
call, it continually monitors the update messages for in­coming call and free repeater information. When mak­ing a call, the mobile may be trunked to any of the site
repeaters that are not busy.

Multi-Net System - An advanced radio system which
provides enhanced operating features such as auto-reg­istration, busy queuing, emergency messages, and pri­ority access. It utilizes trunking similar to an LTR
system.

Public Safety - A radio service used by the Local Gov­ernment, Police, Fire, Highway Maintenance, Forestry
Conservation, and Special Emergency Radio services.

Radio Network Terminal (RNT) - The RNT together
with the System Management Module provide control
of a Multi-Net system. The RNT can interconnect sev­eral different forms of communication to form a com­munication network. Refer to Section 2.1.4 for more
information.

Selectable System - This usually refers to one of the
systems selectable by the transceiver System Select
function. Each selectable system can be programmed
with a unique set of operating parameters such as home
repeater, group ID codes, and unique ID (see Section

3.14.2).

Site - Repeaters that are physically located together and
connected to the same high-speed data bus.

Specialized Mobile Radio System (SMRS) - A con­ventional or trunked radio system owned by an entre­preneur who makes a profit by selling service on the
system. The entrepreneur is licensed for a base/mobile
relay facility and all users of mobiles or control stations
on his system are licensed as SMRS “users”. The entre­preneur can also be licensed as a user on his own sys­tem. An SMRS may provide service to any of the radio
services in the Public Safety and Industrial/Land Trans­portation (PSIT) categories. In addition, the Federal
Government and individuals may be licensed to use an
SMRS.

Status Repeater - One Multi-Net repeater at a site is
designated to transmit update information for all calls
occurring at that site. This repeater is also available for
voice traffic, but is not assigned as a home repeater for
any mobiles because none of its mobiles would have
home channel backup (see Section 2.3 and Section 2.4).

Trunked Radio System - A radio system which utiliz­es multiple radio channels and automatic channel
switching to allow all system uses to access any chan­nel that is not in use. This results in minimum waiting
to make a call and maximum utilization of system chan­nels.

2.3 HOME AND STATUS REPEATERS

When a mobile transceiver is programmed, it is
assigned “home” and “status” repeaters. The home
repeater is used by a mobile as its primary source of
incoming call and free repeater information. When a
mobile is not receiving a call, it is continually moni­toring its home or status repeater for this information.
In addition, the home repeater and group ID code are
used to identify mobiles when standard group calls are
placed.

One repeater at a site is designated as the status
repeater. This repeater transmits update information
for all calls occurring at that site. The status repeater is
also available for voice traffic, but is usually not
assigned as a home repeater for any mobiles. The
reason for this is that mobiles assigned to the status
repeater would not have home channel backup.
However, no degradation in system calling efficiency

2-3

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Part No. 001-8560-381

MULTI-NET SYSTEM OVERVIEW

occurs if the status repeater is assigned as a home
repeater.

A home repeater transmits continuous update
messages when it is in use or if any of its mobiles are
trunked out to another repeater. The status repeater
transmits continuous update messages at all times.
During idle times, non-status repeaters transmit update
messages every 10 seconds. Therefore, a mobile just
coming into service will soon receive information as
to which channel to use.

If the home repeater is being monitored and it is
not busy, it is used to make a call. Otherwise, the
transceiver may be trunked to any repeater at the site
to make a call. The repeater to which a mobile is
trunked is selected randomly.

Group ID codes 1-225 are assignable on each
home repeater for standard dispatch calls. For
example, if the system has ten channels, up to 2250
different group ID codes can be assigned. Group ID
codes specify the specific mobile or group of mobiles
being called and the mobile or group of mobiles from
which calls are received.

2.4 HOME CHANNEL BACKUP (STATUS

REPEATER)

2.4.1 INTRODUCTION

If mobiles were limited to just their home
repeater to receive update information and that
repeater became inoperative, all the mobiles assigned
to that home repeater would not be able to place or
receive calls. To prevent this from happening, each
site utilizing Multi-Net signaling has a repeater called
a status repeater which transmits update messages for
all calls occurring at the site. All mobiles assigned to
the site can receive update messages from either the
status or home repeater. Therefore, if a home repeater
fails, the status repeater can still be monitored for the
information needed to place and receive calls.

2.4.2 SELECTING REPEATER TO MONITOR

monitor. When valid data is detected, that repeater
becomes the monitor repeater. The monitor repeater
does not change unless valid data is no longer detected
or a system programmed for a different site is
selected. Transceiver performance is not affected by
which repeater is being monitored.

2.4.3 ASSIGNING THE STATUS CHANNEL

Each selectable system of a mobile is
programmed with a status channel and also the
number of the site that is accessed by that system. For
proper mobile operation, the same status channel must
be programmed in all systems which access that site.
For example, if systems 1, 3, and 4 access site 128,
those systems must be programmed with the same
status channel.

2.4.4 DETECTING DEFECTIVE REPEATERS

If a repeater is defective, it is important that it is
taken off the air as quickly as possible to ensure that
all transceivers are receiving quality service. To detect
improper operation, calls can be periodically placed
through an optional test mobile by the System
Analyzer. A test mobile is simply a transceiver located
off-site that has attenuated power output. These calls
use the Interrogate special call described in Section

2.8.4, and they are placed through each repeater in the
site. This call exercises the repeater RF receive, RF
transmit, and logic circuitry. If the proper response is
not received from the repeater by the RNT, the SMM
alerts the system operator. The faulty repeater may
then be automatically or manually shut down by the
SMM.

2.5 MOBILE-REPEATER DATA SIGNALING

The setup and control of a call is accomplished
by the exchange of data messages between the mobile
and repeater. This data signaling occurs continuously
with voice because it is at the subaudible frequency of
150 Hz. This allows operation without a dedicated
control channel, and all channels can be used for voice
communication.

Each selectable Multi-Net system of a mobile is
programmed with the channel numbers of the home
and status repeaters. When transceiver power is turned
on, it scans both repeaters to determine which one to

Revised February 1997
Part No. 001-8560-381

When a mobile initiates a call, a data “hand-
shake” occurs with the repeater. This handshake
occurs in only half a second and it tells the mobile that
the system has been successfully accessed and that the

2-4

MULTI-NET SYSTEM OVERVIEW

signal is not occurring on the wrong channel because
of intermodulation. The need to complete a handshake
also prevents a mobile with a stronger signal from
capturing a channel in use.

Data messages are continuously transmitted to
the repeater by the calling mobile while a conversation
is in progress. A repeater is held for only the duration
of the transmission with standard dispatch (mobile-to­mobile) calls. Some special calls, such as telephone
calls, hold the repeater for the duration of the call.

When a mobile is trunked to another repeater to
receive a call, additional data messages are trans­mitted continuously by that mobile’s home repeater,
the status repeater (see Section 2.4), and the repeater
to which the mobile was trunked. The messages on the
home and status repeaters tell mobiles just coming
into service which repeater to switch to in order to
receive the call. Messages on the repeater being used
by the transceiver keep it updated on what calls are
being received by other mobiles assigned to its home
repeater. Therefore, calls with a higher receive priority
are not missed, even when trunked to another repeater.

The sequence of data messages transmitted on a
home or status repeater follows: Every third data
message is the message to the mobile using that
repeater. Then alternating between those messages are
the messages to the other mobiles receiving calls. If it
is a home repeater, these messages are for its assigned
mobiles that are being trunked to other repeaters.

In the case of the status repeater, messages to all
mobiles currently using the site are transmitted. If it
has assigned mobiles, this includes messages to those
mobiles. For example, assume that five different trans­ceivers are making calls. If all have Repeater 1 as their
home repeater, the data message order on Repeater 1
is as follows: 1 2 3 1 4 5 1 2 3 and so on. Therefore, in
this case, the maximum number of data messages that
would occur before repeating is six.

a receiver tuned to the channels being used, that may
even be difficult because the message exchange may
occur on several channels.

Since Multi-Net and LTR signaling is different,
the mobile must be programmed for the type of
signaling being used. For example, if the selectable
system of the mobile is programmed for Multi-Net
operation, it cannot be selected to place calls on an
LTR system and vice versa. However, since all current
Multi-Net transceivers can be programmed for Multi­Net, LTR, and conventional operation, all the user has
to do to place a different type of call is select another
system.

2.6 REPEATER DATA BUS SIGNALING

A single-line, high-speed serial data bus intercon­nects the control logic of the repeaters at a site.
Control information is exchanged between repeaters
via this bus. Repeaters in a Multi-Net system utilize a
logic control technique called distributive processing
in which the logic of each repeater performs all the
control functions on that channel. This eliminates the
need for a separate controller at each site.

When a repeater is in use, it places information
on this data bus which includes the home repeater
number and the group and unique ID code of the
mobile using the channel. This information is moni­tored by the other repeaters at the site so that they can
determine which repeaters are free and also if any of
their assigned mobiles are trunked to other repeaters.

With Multi-Net signaling, repeater data bus
synchronization is done distributively. Therefore, no
single repeater is responsible for data bus synchroni­zation. If any of the repeaters at the site become inop­erative, the others continue to operate normally.

2.7 STANDARD AND SPECIAL CALLS

The calls that can be placed and received are
determined by the ID codes programmed into the
transceiver by the system operator. Therefore, other
users in the system cannot eavesdrop on conversations
of other groups. Although traffic can be monitored by

2.7.1 INTRODUCTION

The two types of calls that can be made with
Multi-Net signaling are Standard (dispatch) and
Special. Group ID codes 1-225 are used for Standard

Revised February 1997

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MULTI-NET SYSTEM OVERVIEW

calls, and group ID codes 226-255 are used for Special
Calls. The following information describes these calls.

2.7.2 STANDARD CALLS

As stated earlier, up to 225 group ID codes are
assignable on each Multi-Net home repeater. When a
transceiver monitors its home or status repeater, it
receives data messages containing a home repeater
number, group ID, and unique ID code (see Section

2.8.1). When it detects its home repeater and a group
ID from 1-225 that it is programmed to decode, it
unsquelches and the call is received. The correct
unique ID code does not need to be detected to receive
a Standard Call.

Standard Calls can be placed only to mobiles
assigned to the same home repeater. However, each
selectable system of a transceiver can be programmed
with a different home repeater which allows calls to
mobiles assigned to other repeaters. Refer to Section

3.15.1 for more information on standard calls.

2.7.3 SPECIAL CALLS

If a group ID from 226-255 is received, a Special
Call is indicated and the transceiver responds
according to the type of call. Special calls are used to
perform many of the special Multi-Net features
described later in this section. The special calls
usually originated by a mobile are Interconnect and
Auxiliary. Most other special calls such as Interrogate,
Mobile Disable, and Reassignment are originated by
the system operator or a dispatcher. Generally, a trans­ceiver must decode its unique ID code to respond to a
Special Call. Refer to Section 3.15.2 for more infor­mation on special calls.

2.8 OTHER MULTI-NET FEATURES

2.8.1 UNIQUE ID CODES

addition to the selected group ID. Any control point
equipped with a console that can receive the call then
displays the ID of the calling unit. This provides auto­matic identification of transceivers making calls.

Unique IDs also permit individual mobile units to
be called. This is done using the special calls
described in the preceding section. Calls can also be
made to individual transceivers using standard call
group IDs 1-225 if an ID code is assigned to only one
transceiver.

2.8.2 ACCESS AND RECEIVE PRIORITY

The priority access feature allows users that have
a greater need to communicate, access to the system
first. There are five levels of priority, with 1 the
highest priority and 5 the lowest priority. Each
repeater determines the current priority level using an
algorithm that is selected by programming switches in
the logic drawer. The access priority information is
then transmitted in the data messages to the mobiles
monitoring that repeater.

When a transceiver is programmed, a priority
level between 1 and 5 is assigned to each group ID
that is encoded (transmitted). If the priority level
transmitted by the repeater is higher than that
programmed for the selected group, a busy indication
is produced when the PTT switch is pressed and the
call cannot be placed at that time.

There is also a priority order when receiving
messages if the selected system of the transceiver is
programmed with two or more receive group ID
codes. This permits a call with a higher priority ID
code to interrupt a call with a lower priority ID code.
Receive priority occurs only with standard group
calls. Telephone and other special calls cannot be
interrupted by standard calls. Refer to Section 3.14.3
for more information.

Each selectable system of a transceiver is
programmed with a unique ID code in addition to the
group ID codes. Unique ID codes are assigned on a
site-wide basis, not on a repeater basis as with group
IDs. Up to 8000 unique ID codes can be assigned per
RNT.

Whenever a transceiver makes a call, it always
transmits the unique ID programmed in the system in

Revised February 1997
Part No. 001-8560-381

2.8.3 ALL CALL

“All Call” is another of the special calls
described earlier. This call goes out to all mobiles
assigned to the site. It can be transmitted by the
system operator or by a dispatcher that is authorized to
do so. It is received by all mobiles assigned to the site
because it goes out to all repeaters simultaneously and
has the highest priority. Therefore, all calls in progress

2-6

MULTI-NET SYSTEM OVERVIEW

are dropped to receive it. If a mobile is turned on, the
only time that this message can be missed is while it is
in the transmit mode.

2.8.4 INTERROGATE

A dispatcher with the proper authority can inter­rogate any mobile unit in the field. A special interro­gate message is sent that contains the unique ID code
of the affected mobile. If that mobile is turned on, it
will automatically transmit a message back to the
dispatcher that identifies it and sends one of eight
status indications which are then displayed at the
dispatch point (see Section 2.8.14). This feature can
be used for such things as determining if a transceiver
is in service or assisting in the recovery of lost or
stolen units. It is also used to detect defective
repeaters (see Section 2.4.4).

2.8.5 MOBILE DISABLE

If a transceiver is lost or stolen or is being used to
interfere with communications or monitor sensitive
transmissions, it can be temporarily or permanently
disabled by the system manager using the Mobile
Disable special call. After this call is sent, verification
is returned by the transceiver indicating that it has
been successfully disabled. To make a permanently
disabled transceiver operational again, it must be
returned for reprogramming.

2.8.6 DYNAMIC REPROGRAMMING

OF GROUP 11

Group 11 of each selectable system of a mobile
can be dynamically reprogrammed over the air. That
group is the only one that can be reprogrammed over
the air and programmed normally. Making only one
group reprogrammable in this manner prevents the
transceiver from becoming inoperative because of a
programming error caused by a poor RF signal.

Dynamic reprogramming is performed by the
system manager. The data transmitted to the mobile
includes the selectable system to be changed, the new
encode and decode ID codes, and the access priority
of the encode code. One use of this feature is to allow
a transceiver to place or receive calls for which it was
not originally programmed.

2.8.7 DYNAMIC MOVE TO NEW SYSTEM/ GROUP

The dynamic reprogramming feature just
described does not change the currently selected group
of the transceiver. This can be done using the dynamic
move to system/group special call. The procedure is
similar to that used for dynamic reprogramming.
When this message is detected by the mobile, it auto­matically switches to the system and group number
contained in the message. One use of this feature is to
make sure that mobiles are set to the correct system/
group to receive an important “all call” message. It
can also be used in conjunction with the dynamic
reprogramming command to send a special message.

2.8.8 ID VALIDATION

ID validation is the process of making sure that
only the mobiles authorized service on the system can
use it. This function is performed by the System
Management Module. Both group and unique ID
codes are checked. If an ID code is detected that is not
authorized for service, a turn-off code is transmitted to
the mobile or mobiles receiving the call. This effec­tively disables the unauthorized mobile because its
calls are not received.

2.8.9 SYSTEM KEY

The system repeaters and all mobiles are
programmed with a unique System Key. The function
of the System Key is to ensure that only authorized
users can access a Multi-Net system. The repeater
System Key is programmed at the factory, and the
mobile system key is programmed into the transceiver
by the system operator. The System Key is a number
which is used by both the repeaters and the mobiles to
encode the data stream. Unless both are programmed
with the proper key, communication is not possible.
The System Key used to program the mobiles is
provided to the system operator by E.F. Johnson.

2.8.10 DYNAMIC CHANNEL ASSIGNMENT

When channels (repeaters) are added to a Multi­Net system, mobiles do not have to be brought back in
for reprogramming because they are informed over the
air as to which channel number to use to place or
receive a call. The only channel numbers programmed
into the mobiles are the home and status channels.

2-7

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MULTI-NET SYSTEM OVERVIEW

2.8.11 EMERGENCY CALLS

An emergency switch is available with all Multi­Net transceivers. This switch can be used in emer­gency situations to quickly place calls or transmit an
emergency code. The transceiver can be programmed
so that the emergency message is transmitted either
automatically or manually.

When automatic operation is programmed, the
transceiver automatically transmits the emergency
code on the designated system/group until an
acknowledgment is received from the dispatcher.
When manual operation is programmed, the trans­ceiver goes to the designated system/group but no
message is automatically transmitted. This ensures
that when the user does transmit the message, it is
transmitted at the highest priority. Refer to Section

3.16 for more information.

2.8.12 AUTO-REGISTRATION

Auto-registration can be used to automatically
track the location of mobiles in multi-site systems.
Calls can then be automatically routed to the correct
site. This eliminates the need to enter the site of the
mobile when placing a call.

Auto-registration occurs only when the mobile is
in the system scanning mode. If the mobile moves out
of radio range of the site in which it is currently regis­tered, it begins searching for another site. When one is
found, it automatically registers on the new site. When
the transceiver is searching for a new site, the user is
alerted by a message in the display. Refer to Section

3.17 for more information.

Most Multi-Net transceivers also have a
programmable parameter called Auto-Registration
Dropout Criteria. This parameter determines the point
at which the mobile attempts to register on another
site. This is controlled by the percentage of good data
messages that the mobile receives over a 10-second
period. If it is programmable, it can be set for 50­100%. If it is not, it is fixed at 50%. This percentage
sets the number of good messages that must be
received to stay on the current site. Therefore, the
higher the percentage, the sooner auto-registration
occurs.

2.8.13 BUSY QUEUING

The busy queuing feature places the call in a
queue if the system is busy when the PTT switch is
pressed. Then when the system becomes available, the
user is alerted by a tone and the call can be placed if
desired. An available system is determined in the
normal manner by the access priority of the selected
group and the current access priority being transmitted
by the repeater. Refer to Section 3.18 for more infor­mation on this feature.

2.8.14 SENDING STATUS INFORMATION

One of up to eight preprogrammed status condi­tions can be transmitted to the dispatcher. Conditions
such as “AT SCENE” or “IN PURSUIT” can be
selected by the user. Then when the transmitter keys, a
number representing that status is transmitted and a
message along with the mobile's unique ID are
displayed on the dispatcher's console. Refer to Section

5.7.4 for more information.

2.8.15 TRANSMIT INHIBIT

The Transmit Inhibit feature prevents the trans­mitter from keying if the mobile being called is busy
with another call. The transceiver is programmed with
a block of transmit inhibit ID codes that can include
up to all 225. If a code within this block is detected up
to 5 seconds before the push-to-talk switch is pressed,
the transmitter does not key and the user is alerted by
a tone and message in the display if applicable. Refer
to Section 3.14.5 for more
information.

2.8.16 VOICE ENCRYPTION

NOTE: Voice encryption is currently not available for
900 MHz transceivers such as the 857x/859x.

Optional voice encryption provides security from
unauthorized monitoring of conversations by casual
eavesdropping and analog scanners. Multi-Net
encryption employs Continuous Sync* technology to
provide fast synchronization and decoding of
messages. This means that calls can be received even
if the transceiver is turned on in the middle of a
message or if a call is entered from the scan mode.

Revised February 1997
Part No. 001-8560-381

2-8

MULTI-NET SYSTEM OVERVIEW

Encryption encodes the audio signal using a
special code sequence. Over five-billion different
codes are available, and only other mobiles with the
same code sequence can receive a call. Encryption is
available on both group and telephone calls (either
mobile- and landside-originated). With telephone
calls, dialing is normally completed before encryption
is enabled.

Encryption can be used with Multi-Net, LTR, and
conventional operation. Each group can be

* Continuous Sync is a trademark of Transcrypt International

programmed for encryption and then when that group
is selected, encryption is automatically enabled. The
user can also manually turn encryption on and off. The

encryption mode is indicated in the display or by a
front-panel indicator.

NOTE: Encryption is not compatible with
companding; therefore, those features cannot be used
together.

An OTAR (Over-The-Air-Reprogramming)
system is available which allows the system operator
to periodically change part of the encryption code and
certain other parameters. This system uses a specially­equipped mobile transceiver, modem, IBM® PC or
compatible computer, and special OTAR software.

2-9

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MULTI-NET SYSTEM OVERVIEW

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2-10

TRANSCEIVER OPERATION

SECTION 3 TRANSCEIVER OPERATION

LCK
SYS

MUTE SCAN PHONE

MON

CALL BUSY

L

S
C

C

N

K

UNREVISED DISPLAY

SYS

MUTE

REVISED DISPLAY

SCN

BUSYCALLMON

S
C
N

L
C
K

Figure 3-1 8560-8565 Transceiver Controls And Display

R
T
N

RCLCLRSTO

PHON

R

T
N

RCLCLRSTO

LCK

GRP

GS

GRP

GS

ANTENNA
ACCESSORY
CONNECTOR
BACKLIGHT SWITCH
AUXILIARY SWITCH
PUSH-TO-TALK
SWITCH
SYSTEM SELECT
PHONE MODE SELECT
SEND KEY
BATTERY RELEASE
BUTTON

TRANSMIT INDICATOR
EMERGENCY BUTTON
ON-OFF VOLUME
SPEAKER
MICROPHONE
SCAN KEY (STORE)
LOCK KEY (CLEAR)
RETURN KEY (RECALL)
GROUP SELECT
TELEPHONE KEYPAD

3.1 OPERATING FEATURES

NOTE: “System” as used in the following informa­tion usually refers to the systems selected by the front­panel System (S) key. Each system can be programmed
with a unique set of operating parameters such as
operating mode (Multi-Net, LTR, or conventional) and
selectable groups or channels.

3.1.1 GENERAL TRANSCEIVER FEATURES

The following features are available regardless of
whether Multi-Net, LTR, or conventional operation is
programmed. Dealer programming determines the
specific operation of some of these features.

• 14 systems

• Each system programmable for Multi-Net, LTR

(except early models), or conventional operation

• 16-position quick select switch (858x only)

• Backlighted LCD (Liquid Crystal Display)

• Optional telephone keypad with 8-number (856x)

or 7-number (858x), 14-digit memory

• System scan

• User programmable system scan list

• User selectable power output (except 8560-8563)

• Call indicator

• Time-out timer

• Cloning capability which allows one transceiver to

program another

• Test mode

• Compatible with vehicular adapter and charger to

allow mobile as well as handheld use.

3.1.2 MULTI-NET AND LTR FEATURES

The following additional features are available
when the selected system is programmed for Multi­Net or LTR operation.

• Up to 11 (Multi-Net) or 10 (LTR) groups per system

programmable

3-1

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Part No. 001-8560-381

TRANSCEIVER OPERATION

SYS

MUTE

QLK

LO SCN

BUSYCALLMON

PHON

U

GRP

ANTENNA
ACCESSORY CONNECTOR
BACKLIGHT SWITCH
AUXILIARY SWITCH
MICROPHONE
PUSH-TO-TALK SWITCH
SYSTEM SELECT
PHONE MODE SELECT
SEND KEY
BATTERY RELEASE
BUTTON

S–

S

QSTO

S
C
N

STO

OPT

CLR

2ND

L
C
K

RCL

G–

R
T

G

N

QUICK SELECT SWITCH
TRANSMIT INDICATOR
EMERGENCY BUTTON
ON-OFF VOLUME
SPEAKER
DISPLAY
MICROPHONE
SCAN KEY (STORE)
LOCK KEY (CLEAR)
RETURN KEY (RECALL)
GROUP SELECT
TELEPHONE KEYPAD
BATTERY PACK

Figure 3-2 8585-8588 Transceiver Controls And Display

• Up to all the following ID codes are programmable

in each system:

– 11 (Multi-Net) or 10 (LTR) encode and decode

ID codes selectable by Group switch

– 2 fixed priority decode ID codes
– Block of decode codes

• Group scan

• User prog group scan list (Multi-Net only)

• A unique 5-character group (Multi-Net only) or

7-character system identification can be displayed

• Transmit inhibit

• Clear-to-talk (proceed) tone

• Talk-around to permit mobile-to-mobile communi-

cation

• A unique 7-character system identification can be

displayed

• Receive-only channels

• Transmit disable on busy

3.2 TRANSCEIVER CONTROLS AND DISPLAY

NOTE: The 8560-8568 controls and display are
shown in Figure 3-1, and the 8585-8588 controls and
display are shown in Figure 3-2.

3.2.1 CONTROLS

3.1.3 CONVENTIONAL FEATURES

The following additional features are standard
when the selected system is programmed for conven­tional operation.

• Up to 10 channels (groups) per system selectable

• Tone or digital Call Guard squelch or standard

carrier squelch programmable on each channel

Revised February 1997
Part No. 001-8560-381

On-Off/Volume - Turning the knob clockwise turns
power on and sets the volume level. Turning it
counter-clockwise to the detent turns power off.
Power is on when information appears in the display.
If the key press tone is enabled, any function key
except backlight can be pressed to provide a reference
for setting the volume level. Otherwise, the volume
level can be determined by noting the position of the
index on the volume knob.

3-2

TRANSCEIVER OPERATION

Quick Select Switch (858x Only) - Selects up to 16
preprogrammed system/groups. The system/ group for
a position is programmed by pressing 2ND QSTO or
by system operator programming. Refer to Section

3.11 for more information.

Emergency Switch - This switch is pressed to manu­ally or automatically place a high-priority call. A beep
sounds to indicate when this switch is pressed. Refer
to Section 3.16 for more information.

Accessory Connector - The connection point for the
optional vehicular adapter and charger. It is also used
for transceiver programming and connecting other
optional accessories (see Table 1-2).

Push-To-Talk Switch - Pressing the lower half of the
rubber switch pad on the side of the transceiver keys
the transmitter. The transmitter is keyed whenever the
red indicator on the top panel is lighted and “TX”
appears in the display.

Auxiliary - Pressing the upper middle part of the
rubber switch pad on the side of the transceiver tempo­rarily suspends system and/or group scanning and
causes the revert system/group to be displayed. When
a conventional system is selected, this switch also
selects the monitor mode (see Section 3.21.3).

With the 8585-8588, turning power on with this
switch pressed selects the menu mode that is used to
select various functions (see Section 3.12).

With the 8585-8588, pressing 2ND (RTN) and then
this switch decreases the system number.

G (Group) - This key functions like the System key to
select the group.

SCN (Scan) - Turns the system scan feature on and
off. System scanning is enabled when “SCAN” is indi­cated in the lower part of the display and actually
occurring when “IN SCAN” is displayed in the upper
part of the display. Turning power on with this key
pressed enables and disables the key press tone.

With the 8585-8588, pressing 2ND (RTN) and
then this key programs the current quick select switch
position with the displayed system/group (see Section

3.11).

LCK (Lock) - Used to delete (lock out) systems and
groups from the scan list so that they are not scanned.
Pressing this key changes the status of whatever
system or group was selected last. The lockout indi­cator is “

▼” (revised display) or “LCK” (unrevised

display) above “SYS” or “GRP”. Refer to Section

3.3.6 for more information.

With the 8560-8568, turning power on with this
key pressed disables all keys except push-to-talk and
backlight. The keypad then remains locked even
during power off and on cycles. To re-enable the
keypad, turn power on again with this key pressed.
Refer to Section 3.9.1 for more information.

Backlight - With the 8560-8568, pressing the upper
part of the upper rubber switch pad on the side of the
transceiver lights the display so that it can be seen in
low-light conditions. With the 8585-8588, the back­light stays on for 10 seconds after this switch is
pressed or it can be turned off immediately by pressing
the switch again.

Battery Release Button - Pushing this spring-loaded
button upward releases the battery so that it can be
turned and removed for recharging or replacement.

S (System) - Pressing this key increases the selected
system by one. Holding it down causes the function to
repeat. Only programmed systems can be selected.
After the highest programmed system is displayed, the
display rolls over to the lowest programmed system.

With the 8585-8588, the keypad disable function
is selected using the menu. Pressing 2ND (RTN) and
then this key toggles an auxiliary function such as
encryption on and off (see Sections 3.12 and 3.13.8).

RTN (Return) - With the 8560-8568, pressing this
key displays either the home system/group or the
currently selected system/group (see Section 3.8).

With the 8585-8588, pressing this key once
enables the second function of the S, G, SCN, and
LCK keys. Pressing it twice selects the return function
described in the preceding paragraph.

NOTE: The following keys are available only if the
transceiver is equipped with the optional telephone
keypad (see Section 3.19).

Revised February 1997

3-3

Part No. 001-8560-381

TRANSCEIVER OPERATION

Telephone Keypad - 0-9, *, and # keys which are
used for dialing a telephone number.

PHON (Phone) - Turns the phone mode on and off.

SND (Send) - This key can be pressed instead of the

PHON key to select the phone mode. The system/
group preprogrammed for telephone calls is then auto­matically selected. Pressing this key after the phone
mode is selected transmits the telephone number in the
display.

NOTE: The next three keys are dual-function keys
which operate as described when the phone mode is
selected and as described in the preceding information
when the standard mode is selected.

STO (SCN) - Pressing this key and then a number key
from 1-8 (8560-8568) or 1-7 (8585-8588) stores the
number in the display in that memory location.

CLR (LCK) - Erases the last digit of the phone
number in the display. Holding this key down causes
the function to repeat. Pressing RCL and then CLR
erases the entire phone number.

RCL (RTN) - Pressing this key steps through the
phone numbers stored in memory. Pressing this key
and then the number of a memory location from 1-8
(8560-8568) or 1-7 (8585-8588) displays the tele­phone number stored in that location.

3.2.2 DISPLAY INFORMATION

System Display - Indicates the selected system
number.

turn this indicator off, press any key except backlight.
Refer to Section 3.6 for more information.

▼ (LCK) - This symbol appears above “SYS” or

“GRP” to indicate if the system or group is locked out
(deleted from scan list). When scanning, the system or
group lockout indicator appears if any scanned system
or group is locked out. Refer to Section 3.3.6 for more
information.

MUTE - Indicates that the key press tone is muted.
The status of this tone is changed by turning power on
with the SCN key pressed (8560-8568) or by selecting
the menu mode (8585-8588).

- Indicates that the transmitter is on. The red

indicator on the top panel also indicates that the trans­mitter is on.

BUSY - When a conventional system is selected, indi­cates that the channel (group) is busy. Refer to Section

3.21.3 for more information.

MON - When a conventional system is selected or
scanned, indicates that the monitor mode has been
enabled by the Auxiliary switch on the side of the
transceiver. The monitor mode disables Call Guard
squelch so that all messages occurring on a channel
are heard.

PHONE - Indicates that the phone mode has been
selected by the PHON or SND key.

- Indicates that the displayed group is
programmed for telephone calls (Multi-Net and LTR
systems only).

Group Display - Indicates the selected group number.

SYS (System) - Always displayed above the system

number when power is on.

GRP (Group) - Always displayed above the group
number when power is on.

SCN (SCAN) - Indicates when the system scan mode
has been selected by the SCN key. However, system
scanning is not actually occurring until “IN SCAN” is
indicated in the upper part of the display.

CALL - Indicates that a call has been received. To

Revised February 1997
Part No. 001-8560-381

- Indicates that the battery needs recharging.

- Indicates that the displayed telephone number
contains more than the 7 digits currently being shown.
To momentarily display the overflow digits, press
RCL 0.

Alphanumeric Display - In the standard (non-phone)
mode, this display indicates either the 5-character
group identification or the 7-character system identifi­cation. (The 5-character group identification is
programmable on Multi-Net systems only.) In the
phone mode, this display indicates the telephone
number being dialed. Operating modes and error

3-4

TRANSCEIVER OPERATION

conditions may also be indicated by this display as
described in Section 3.22.

NOTE: For information on telephone calling, refer to
Section 3.19.

8585-8588 DISPLAY INFORMATION

- Indicates that optional voice encryption or some

other accessory is enabled. The accessory is turned on
and off by pressing 2ND OPT (RTN LCK).

U - Indicates that the displayed group is programmed

for a Multi-Net unique ID call.

QLK - Indicates that the current quick select switch
position is locked and cannot be user programmed.

LO - Indicates that the low-power mode has been

selected from the menu mode.

3.3 SYSTEM SCAN

3.3.1 GENERAL

System scanning is turned on and off by the front
panel SCN key. This feature is always available
because the SCN key cannot be disabled by program­ming. The scan mode is indicated by “SCN” in the
display. When scanning is actually occurring, “IN
SCAN” appears in the display in place of the unique
system or group identification, and the system and
group numbers change to dashes. Scanning is sequen­tial through all programmed systems unless they are
deleted from the scan list as described in the Section

3.3.6.

NOTE: 858x/859x transceivers display the system
number while scanning is occurring. This allows the
user to determine the current system when auto­registration is used (see Section 3.17). This has not
been implemented in 856x/857x transceivers.

When an incoming call is detected, scanning
stops and the call is received. The display usually indi­cates the system and group on which the call is
received so that a response can be made without
changing the selected system and group. An exception
may be calls on Multi-Net/LTR fixed priority or block
ID codes (refer to Section 3.14.3).

3.3.2 SINGLE-SITE AND MULTIPLE-SITE SCAN

When the transceiver is programmed, either
Single-Site or Multiple-Site system scanning is speci­fied. These types of scanning operate as follows:

Single Site Scan - With this type of scan, calls are
detected on one site only. A site is defined as a group
of repeaters that are interconnected by the same high­speed data bus.

Therefore, if there is only one site that can be
accessed, this is the type of scan that is always
programmed. If several sites can be accessed, only the
site of the revert system is scanned. For example, if
System 2 was displayed when scanning was turned on,
only the site programmed in that system is scanned.

Only Multi-Net systems are scanned by Single
Site scan. Therefore, if LTR or conventional systems
are also programmed, they are skipped in the scan
sequence. If an attempt is made to turn on scanning
with an LTR or conventional system displayed, scan­ning is not allowed. Refer to Sections 2.4 and 4.5.5 for
more information on sites.

When scanning is occurring with this type of
scanning programmed, the transceiver normally moni­tors only the status channel of the site. Therefore, this
type of scanning is very efficient because no waiting is
required for the transceiver to change channels. The
data words decoded are checked against the home
repeater/group ID codes of all selectable systems
programmed with that site number to determine if
there is a match.

If no traffic is detected on the status channel for a
period of time, the transceiver begins scanning the
home repeaters of all systems programmed with the
site number being scanned. This ensures that scan­ning occurs even if the status repeater is not on the air.
The status channel also continues to be scanned, and
normal scanning of the status channel resumes when
messages are again detected. When home repeaters
are scanned, data messages are decoded for only as
long as necessary to detect all calls on that repeater.

Multiple-Site Scan - This type of scan is programmed
when more than one site is scanned or if LTR or con­ventional systems are to be scanned. Scanned are status

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TRANSCEIVER OPERATION

channels of Multi-Net systems, the home repeater of
LTR systems, and the revert (last-selected) channels of
conventional systems. As with Single-Site Scan, if the
status channel of a particular Multi-Net site is not in
service, the home channels are scanned until messages
are again detected on that status channel.

3.3.3 RECEIVE AND TRANSMIT SCAN DELAYS

After a message is received in the scan mode,
there is a Receive Delay Timer that delays the resump­tion of scanning. If scanning resumes immediately,
some other message may be received and the selected
system/group would have to be changed to respond.
The Receive Delay Timer can be programmed for 1, 2,
3, 4, 5, 6, or 7 seconds or “8”.

With 8560-8568 transceivers, “8” programs an
infinite time. This causes the scan mode to be exited
and the system/group of the call becomes the revert
system/group. With 8585-8588 transceivers with
Version 206 software or later (units shipped starting
November 1995), programming “8” selects an 8-
second delay and the “Last Received Revert” configu­ration described in Section 3.3.4. The “8” parameter is
not available with earlier 858x transceivers. NOTE:

The software version is displayed when the test mode
is entered (it is the last three digits displayed).

After transmitting a message in the scan mode,
there is a Call Delay Timer that delays the resumption
of scanning. This delay ensures that a response to a
message is heard instead of some other message
occurring on another system or group. This delay
period can be programmed for the same times as the
receive delay just discussed (except for “8” which is
not available with any 858x transceiver).

When the transmitter is keyed when system or
group scanning, the transmission occurs on the revert
system/group. This is always the system/group that
was displayed when the scan mode was entered except
if it has been changed using the S and G keys. To
display the revert system and group while scanning,
temporarily halt scanning by pressing the Auxiliary or
SCN switch. If a message is received while scanning,
scanning stops and the system/group of the call is
displayed. If the transmitter is keyed to respond to the
call, Fixed Revert programming determines the
system/group on which the response occurs. Operation
with each configuration is as follows:

Temporary (Fixed = No) - With this configuration, a
response can always be made to the call without having
to change the selected system/group as long as it occurs
before the scan delay expires (see Section 3.3.3). If the
transmitter is keyed after scanning resumes, transmis­sions occur on the revert system/group (which does not
change when a call is received).

For example, if System 1/Group 2 were displayed
when scanning was turned on and a call is received on
System 2/Group 4, System 2 and Group 4 are
displayed and the call is received. If a response is then
made, it occurs on System 2/Group 4. However, if it is
not made before scanning resumes, it occurs on the
revert system/group which is System 1/Group 2 in this
example. This configuration may be programmed if
responses must be made to messages occurring on
different systems and groups while scanning.

NOTE: With 858x transceivers, if the quick select

switch is turned to a “locked” position (see Section

3.11), the following “Last Selected” configuration is
always active.

If the scan mode is selected after transmitting or
receiving a message, actual scanning does not begin
(“IN SCAN” displayed) until the applicable delay
time expires. The receive and transmit scan delay
times are transceiver parameters, so these times are
the same for all programmed systems.

3.3.4 TRANSMITTING WHILE SCANNING

NOTE: If Auto-Registration is used, revert system
selection may be controlled by auto-registration. Refer
to Section 3.17 for more information.

Revised February 1997
Part No. 001-8560-381

Last Selected (Fixed = Y) - With this configuration,
the transceiver always transmits on the revert system/
group, even when responding to a call. If this was pro­grammed in the preceding example, transmission
would occur on System 1/Group 2 not System 2/Group

4. To respond to that call, the selected system and group
would have to be changed manually using the S and G
keys. The system and group of a call can also be made
the revert system/group by turning off scanning before
scanning resumes. This configuration may be pro­grammed if other calls are normally only monitored
while scanning and most transmissions occur on the re­vert system/group.

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TRANSCEIVER OPERATION

Last Received - With later model 858x transceivers,
programming a “Receive Delay” time of 8 seconds (see
Section 3.3.3) causes the revert system/group to change
to the system/group of a call. Therefore, response can
always be made to a call without changing the selected
system/group. This scheme is also selected in early
model 856x/857x transceivers by the “Fixed Revert =
N” configuration. The Return key can also be pro­grammed to select the last received system/group.

3.3.5 SCANNING OF GROUPS IN SYSTEM

SCAN

If Group Scan is not programmed on a scanned
Multi-Net or LTR system (refer to Section 3.4), calls
are detected on only the revert (last selected) group of
that system when system scanning. However, if Group
Scan is programmed, calls are received on all select­able groups. Calls are detected on all fixed priority and
block ID codes of a selected or scanned system regard­less of Group Scan programming. The priority order of
the various ID codes is the same as when not scanning
(refer to Section 3.14.3). Since Group (channel) Scan
is not available on conventional systems, calls on
those systems are detected on only the last selected
group.

programmed system is locked out; likewise, the group
lockout indication appears if any group of a scanned
system is locked out. If all locked-out groups are in
locked-out systems, the group lockout indication does
not appear.

To determine which systems or groups are locked
out, step through the programmed systems and groups
while watching the lockout indicator. The scan list
status is stored in the EEPROM. Therefore, turning
power off does not alter the status of any system or
group.

3.3.7 SCANNING CONVENTIONAL SYSTEMS

If conventional systems are scanned, calls are
received on only the last selected (revert) group
because group scan is not available. For example,
assume Groups 1-4 are programmed in a conventional
system. If Group 2 was the last selected group of that
system, it is the only group on which calls are received
in that system while scanning. Only the last selected
channel is scanned in conventional systems to prevent
the scanning rate from being very slow, especially if a
large number of channels were programmed with Call
Guard squelch.

3.3.6 SCAN LIST PROGRAMMING

Systems can be deleted from and also added to
the scan list by the LCK (lock) key. On Multi-Net
systems, the group scan list can also be programmed
by the user if the Group Scan feature has been enabled
by dealer programming (see Section 3.4). Group scan
list programming is not available on LTR and conven­tional systems.

Pressing the LCK key changes the scan list status
of the selected system or group, whichever was
selected last. For example, if the system select switch
was pressed last, pressing the LCK key once deletes
(locks out) the displayed system (if it was unlocked),
pressing it again adds it back, and so on.

When the indicated system is locked out, “

▼”

(revised display) or “LCK” (unrevised display)
appears above “SYS” in the display. Likewise, when
the indicated group is locked out, this indication
appears above “GRP” in the display. When system
scanning, the system lockout indication appears if any

If Call Guard squelch is programmed on the
group being scanned, it is detected (if it has not been
disabled by the monitor mode). Conventional systems
can be locked out of scanning the same as Multi-Net
systems. Priority channel sampling is not available on
conventional systems.

3.4 GROUP SCAN

Group scan is available only with Multi-Net and
LTR systems. When Group Scan is programmed on a
selected or scanned system, all selectable groups are
decoded regardless of which is selected. Group scan­ning is enabled whenever the system is selected or
scanned (system scan does not need to be selected).
When system scanning is turned off, group scanning is
indicated by a dash in the group display (the system
display continues to indicate the system number).
However, when system scanning is occurring, both
displays indicate a dash even if group scan is not
programmed.

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As when system scanning, group scanning is
inhibited for the programmed scan delay after a call is
received or transmitted (see Section 3.3.3). When
group scanning and a call is received on one of the
selectable groups, the display automatically changes
to the group of that call. The programming of “Fixed
Revert = Yes/No” determines if the selected system/
group must be changed to respond to the call (see
Section 3.3.4). Group scan is not available on conven­tional systems as described in the preceding section.

3.5 TIME-OUT TIMER

The Time-Out Timer disables the transmitter if it
is keyed continuously for longer than the programmed
time. It is programmed in half-minute increments
from 0.5-5 minutes. It cannot be disabled entirely. If
the transmitter is keyed continuously for longer than
the programmed time, the transmitter is disabled, the
intercept tone begins sounding, and “TX TIME”
appears in the display. The timer and tone are reset by
releasing the push-to-talk switch. The Time-Out Timer
can prevent a repeater from being kept busy for an
extended period by an accidentally keyed transmitter.
It can also prevent possible transmitter damage caused
by overheating.

3.6 CALL INDICATOR

The purpose of the call indicator is to show that a
call was received while the user was away from the
transceiver. This indicator is the word “CALL” in the
lower part of the display, and it is turned off by
pressing any key except backlight. The displayed
system and group are usually those on which the call
was received. An exception is if more than one call is
received and the last one did not enable the call
indicator.

With Multi-Net and LTR systems, each of the
two fixed priority ID codes and the selectable decode
codes can be programmed to enable the Call indi­cator. However, it is not activated by block ID codes.
With conventional systems, each channel (group) can
be programmed for the call indicator. If Call Guard
squelch is also programmed on a channel, it must also
be detected for the call indication to appear (unless
Call Guard squelch is disabled by the monitor mode).

3.7 HORN ALERT

When this transceiver is used with the optional
vehicular adapter and remote control unit, the horn
alert feature can be used to signal an incoming call
while the user is away from the vehicle. The same
types of ID codes or channels that can be programmed
to enable the call indicator can also be programmed to
enable the horn alert.

When a call is received on the proper ID code or
channel, the horn alert output turns on once per second
for 3 seconds and then goes back to the off state. The
horn alert output is on the system interface unit, and is
active only when the ignition switch is off with trans­ceiver power still on. Refer to Section 5.7.3 for more
information.

3.8 RETURN (RTN) KEY OPERATION

NOTE: With 8585-8588 transceivers, the following
operation is selected by pressing the RTN key twice.
Refer to Section 3.13 for more information.

The Return (RTN) key is used to quickly return
to either the home or the last active system/group.
Dealer programming determines which is displayed
and also the length of time that it is displayed. The
system/group may be displayed briefly (1-7 seconds)
or permanently (infinite) so that it becomes the
selected system/group. (The infinite setting is not
available with the 8585-8588.)

If the Return key is programmed to display the
home system/group, the system/group that has been
programmed as the “home” is displayed. If it is
programmed to display the last active system/group,
pressing this key while scanning displays the system/
group that was displayed when scanning resumed.
This may be the revert system/group or the system/
group of the last call. If it is pressed when not scan­ning, it has no affect because the last active system/
group is already being displayed.

With the 8560-8568 only, the system/group that
is displayed when the Return key is pressed can be
made the revert system/group by pressing the key a
second time. This can also be done by pressing other
function keys such as PTT, S, SCN and G while the

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3-8

TRANSCEIVER OPERATION

system/group is being displayed. This also turns scan­ning off if it was enabled. If “infinite” is programmed,
this operation occurs when the Return key is pressed
only once. Since Return key programming is a trans­ceiver parameter, operation is the same on all
programmed systems.

3.9 KEYPAD DISABLE, KEY PRESS TONE, AND LOW BATTERY INDICATOR

3.9.1 KEYPAD DISABLE

NOTE: With 8585-8588 transceivers, this feature is
controlled by the menu mode described in Section

3.12.

Occasionally, the front-panel keys may be acci­dentally pressed. This could happen, for example, if
the transceiver is carried in a holster and brushes
against other objects. To prevent this from happening,
all keys except push-to-talk and backlight can be
disabled by turning power on with the LCK key
pressed. If a key is then pressed, all that happens is
that “KEYLOCK” is indicated in upper part of the
display. To re-enable the keys again, simply turn
power on again with the LCK key pressed. Turning
power on without the LCK key pressed has no affect
on the lock status of the keypad.

3.9.2 KEY PRESS TONE

NOTE: With 8585-8588 transceivers, this feature is
controlled by the menu mode described in Section

3.12.

A short tone normally sounds when all keys
except push-to-talk and backlight are pressed. If this
tone is annoying to the user, it can be disabled by
turning power on with the SCN key pressed. “MUTE”
then appears in the display to indicate that the key
press tone has been disabled. To re-enable this tone,
turn power on again with the SCN key pressed.

The key press tone is not heard by the other party
when transmitting because the microphone audio
signal is muted while it sounds. Disabling the key
press tone has no affect on the speaker audio which is
still heard normally. It also has no affect on the tone
that sounds when the emergency switch is pressed.

Later versions of the programming software have
a question which allows the Auxiliary key tone to be
enabled or disabled. This question does not apply to
856x/857x transceivers which always have this tone
enabled (if the key press tone is enabled). The Auxil­iary key tone is programmable with 858x/859x trans­ceivers only.

3.9.3 LOW-BATTERY INDICATOR

When the battery voltage drops below approxi­mately 6.2 VDC, the low-battery indication
appears in the display. In addition, a beep sounds
when this indication initially appears and when the
push-to-talk switch is released (if the key press tone
has not been disabled). The low battery indication is
turned off by turning power off and then on again. The
battery should be recharged as soon as possible after
this indication appears. Refer to Section 5.1 for more
information.

3.10 HIGH/LOW POWER SELECT

NOTE: With 8585-8588 transceivers, this feature is
controlled by the menu mode described in Section

3.12.

The 8565-8568 and 8585-8588 transceivers have
selectable high (3.0 or 2.5 watt) and low (1.8 or 1.5
watt) power output. (The Viking CK and CM have the
higher output as described in Section 1.2.4) To toggle
between these two levels, turn power on with the RTN
key pressed. When high power is selected with the
8565-8568, “HI PWR” is flashed in the upper part of
the display, and when low power is selected, “LOW
PWR” is flashed. This is the only time this informa­tion is displayed. The high power may increase range,
but decrease battery life. The opposite may occur with
the low power setting.

NOTE: With later model 8560-8563 transceivers, the
high and low power information is flashed in the
display even though no change in power occurs (the
1-watt level is always selected). This happens because
the same software is used in all 856x/857x
transceivers

This transceiver saves most operating parameters
in the EEPROM. Therefore, when power is turned on,
parameters such as selected system/group and scan

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TRANSCEIVER OPERATION

mode return to the state they were in when power was
turned off.

3.11 QUICK SELECT SWITCH (858X ONLY)

3.11.1 GENERAL

The rotary quick select switch on the top panel of
8585-8588 transceivers can be used to select up to
sixteen preprogrammed system/group combinations.
The positions can be programmed by the user as
described in the next section or they can be
programmed by the system operator.

Positions programmed by the system operator
can be locked so that they cannot be reprogrammed.
When a locked position is selected, the front panel S
(System) and G (Group) select keys are disabled. This
ensures that the system/group programmed for that
position is always selected. This is especially useful
when the display cannot be viewed, such as when
carrying the transceiver on the belt. Auto-registration
and the return function of the RTN key are also
disabled when a locked position is selected. With later
transceivers which have the revised display, QLK
indicates that a locked position is selected. When the
remote control unit is used with the vehicular adapter,
it is indicated by “OPT 3". With others, there is no
indication.

a. Set the quick select switch to the position to be

programmed.

b. Select the system/group for that position by press-

ing the front panel S (System) and G (Group) keys.
If these keys are disabled, either the switch position
is locked and cannot be reprogrammed or the key­pad is locked.

c. Press the 2ND (RTN) key and then the QSTO

(SCN) key to program the position. If “LOCKED”
is displayed and a beep sounds, the switch position
is locked and cannot be reprogrammed.

3.12 MENU MODE (858X ONLY)

The 8585-8588 transceivers have a menu mode
that is used to select keypad disable, key press tone,
clear-to-talk tone level, and power output. To select
this menu mode, proceed as follows:

a. Turn transceiver power on with the Auxiliary

switch on the side pressed. Then quickly press the
Auxiliary switch to display the parameter to be
changed.

b. Press the PTT switch to select the desired configu-

ration. Normal transceiver operation resumes 2 sec­onds after a parameter is changed.

If the quick select switch is turned while trans­mitting, the system/group does not change until the
PTT switch is released. The system/group also does
not change if a position has not been programmed or
is programmed with an invalid system/group. The dot
(

● ) position is a selectable position the same as posi-

tions 1-15. Stops can be installed to limit the rotation
of the switch to the positions that are programmed.
For example, the switch may rotate only to positions
1-6. Installation of these stops is described in
Section 1.11.

3.11.2 PROGRAMMING A POSITION FROM

THE FRONT PANEL

Any selectable switch position can be
programmed from the front panel if it has not been
locked by system operator programming as described
in the preceding section. Proceed as follows to
program a position:

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The parameters and the available configurations

for each are as follows:

HI PWR - N/A (power output is always 1W)
LO PWR - N/A (power output is always 1W)

PTT 1TN - Single (soft) clear-to-talk tone.
PTT 2TN - Dual (loud) clear-to-talk tone.
PTT 0TN - Clear-to-talk tone disabled.

KP_ENAB - Normal operation
KP_MUTE - Key press tone disabled
KP_LOCK - Keypad and Auxiliary key disabled

For example, to disable the keypad, turn power
on with the Auxiliary switch pressed. Then quickly
press the Auxiliary switch again until one of the
“KP_xxxx” configurations are displayed. Then press
the PTT switch to display “KP_LOCK”. When normal

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TRANSCEIVER OPERATION

operation resumes in 2 seconds, the keypad will be
locked.

3.13 OTHER 858X FEATURES

3.13.1 SYSTEM AND GROUP SELECT

Pressing the 2ND (RTN) key before pressing the
System or Group key allows the selected system or
group number to be decreased as well as increased.

3.13.2 DISPLAYING SYSTEM NUMBER

DURING SCAN

The system number is displayed while scanning.
This is different than the 8560-8568 transceivers
which display a dash in place of the system number
while scanning. Displaying the system number during
scan is especially useful with auto-registration
because it automatically changes the selected system.

3.13.3 LOUD/SOFT CLEAR-TO-TALK TONE

A single (soft) tone, double (loud), or no clear-to­talk tone can now be selected by the menu mode
described in Section 3.12.

3.13.4 EMERGENCY SWITCH TONE

The tone that sounds when the emergency switch
is pressed sounds longer to make it easier to hear.

3.13.5 BACKLIGHT

The backlight stays on for 10 seconds when the
backlight switch is pressed. Pressing that switch a
second time turns the backlight off.

transceivers by pressing the RTN key once. All func­tions of this key except 2ND LCK are disabled if the
quick select switch is turned to a locked position (see
Section 3.11). In the phone mode, the RTN key
continues to be the recall (RCL) key.

Pressing the RTN key twice (or another key) does
not make the displayed system/group the selected
system/group as with the 8560-8568. However, if the
push-to-talk switch is pressed while the return system/
group is displayed, the transmission occurs on that
system/group. Then when the scan delay expires, the
display returns to the selected system/group (this
delay applies even if scanning is not enabled). An
exception is if Fixed Revert is programmed. If the
return system/group is then selected, transmission
occurs on the selected system/group.

3.13.7 AUXILIARY SWITCH TONE ENABLE/DIS-

ABLE

The beep that sounds when the Auxiliary switch
is pressed can now be enabled or disabled by
programming. With the 8560-8568, it is enabled all
the time.

3.13.8 OPTION ENABLE/DISABLE

Pressing 2ND (RTN) and then the LCK key
toggles the Q2 output of shift register U204 on the
motherboard. This output controls an optional acces­sory. When accessory is enabled, this output goes low
and is displayed. (With the remote control unit,
SCRAMBLE is displayed.) Turning power off resets
this output to the off mode which is a high state.
Pressing only the LCK key programs the scan list as
with the 8560-8568.

3.13.6 RETURN KEY

Pressing the RTN key once selects the second
(2ND) function of the S, G, SCN, and LCK keys. The
display indicates “2ND” to show that the second func­tion is enabled. The second function is active for 2
seconds and then the primary function is again active.

Pressing the RTN key twice displays the home or
last displayed system/group for 1-7 seconds, what­ever is programmed. (The infinite time is not avail­able.) This operation is produced with the 8560-8568

3.14 MULTI-NET AND LTR FEATURES

3.14.1 LTR FEATURES

There are both Multi-Net and LTR versions of the
8560-8568 transceiver (the 8585-8588 is available in
the Multi-Net version only). The Multi-Net version
can be programmed for all three modes (Multi-Net,
LTR, conventional), and the LTR version can be
programmed for only the LTR and conventional
modes. Not all LTR features are available with the
Multi-Net version. The features that are not available

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TRANSCEIVER OPERATION

are as follows. These features are available only with
the LTR version.

Free System Ringback
System Search
Transpond

The information which follows in this section
(3.14) applies to both Multi-Net and LTR operation
unless noted otherwise. Form more information on
LTR operation, refer to Section 2 of the LTR 8560­8568 Service Manual, Part No. 001-8560-005.

3.14.2 SELECTABLE SYSTEMS AND GROUPS

Systems

When a system is programmed for Multi-Net or
LTR operation, information such as repeater channel
numbers, home repeater, all encode and decode ID
codes, and the emergency system/group is specified.
The ID codes can be fixed, selectable, and block
types. The types of ID codes and the number that can
be programmed in each category are as follows. Any
combination of codes can be programmed and all
codes can be different.

Decode (Receive) Encode (Transmit)

3.14.3 RECEIVE PRIORITY ID CODES

With standard (dispatch) calls, the fixed, select­able, and block ID codes have a priority order so that
an incoming call with a higher priority ID code can
interrupt a lower priority call in progress. (Conven­tional systems do not have priority with this
transceiver.)

One use of receive priority is to allow someone
such as a dispatcher to interrupt calls in progress with
an important “all call” message. If the transceiver
detects a call with a higher priority ID than the one it
is receiving, it immediately drops the current call and
switches to another repeater to receive the higher
priority call. Telephone calls are not interrupted by
priority calls. The priority order of the decode ID
codes is as follows:

1. Fixed Priority ID Code 1

2. Fixed Priority ID Code 2

3. Selected ID Code

4. Block ID codes

For example, if a call is being received on select­able group 4 and a call is detected on fixed priority ID
2, the call on group 4 is immediately dropped and the
transceiver switches to the call on fixed priority ID 2.

Fixed

2N/A

Selectable
11 (Multi-Net) 11 (Multi-Net)
10 (LTR) 10 (LTR)

Block
Up to all 225 (Multi-Net) N/A
Up to all 250 (LTR) N/A

Groups

The group select function chooses the selectable
ID codes. Only the selected ID code is encoded when
transmitting (it is not possible to encode more than
one code). The group scan feature (see Section 3.3.5)
determines if calls are received on all or only the
selected ID code of a selected or scanned system.
Without group scan, calls are detected on only the
selected ID code; with group scan, they are detected
on all selectable codes in that system.

The fixed decode codes and the block codes are
always decoded regardless of which group is selected
or group scan programming (if the system is selected
or scanned). With Multi-Net operation, when a fixed
ID code is detected, the selectable ID codes are
checked to see if any are the same. If a match is found,
the display changes to that group. If no match is
found, the display does not change. With LTR opera­tion, the display changes to group 1 when fixed ID 1 is
detected and to group 2 when fixed ID 2 is detected.
With both types of operation, the display does not
change when a block ID code is decoded.

If a change to a selectable group occurs, the scan
revert mode programming described in Section 3.3.4
determines if the change to the new group is tempo­rary or permanent and if a transmission occurs on the
new group. In addition, if the change is not permanent,
the programming of the scan delay described in
Section 3.3.3 determines how long the transceiver
stays on the priority group.

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TRANSCEIVER OPERATION

With Multi-Net operation, incoming call infor­mation is received on both the status repeater and the
repeater to which the mobile is trunked (refer to
Section 2.4). Therefore, a priority call is not missed
even when some repeater other than the home repeater
is being used.

With LTR operation, incoming call information is
received on only the home repeater. Therefore,
priority calls are not detected while trunked to some
other repeater. To reach most mobiles with a priority
message in this case, the operator can key the trans­mitter and then not begin speaking for several
seconds. This allows trunked-out mobiles time to
finish the transmission and return to the home
repeater. This still may not reach mobiles making tele­phone calls because they hold a repeater for the dura­tion of a conversation (instead of the duration of the
transmission as with dispatch calls).

Other times when priority calls could be missed
with both types of operation are when some other
system not programmed with the priority ID is being
monitored and while transmitting.

With Multi-Net operation, certain types of special
calls may interrupt standard and other special calls.
Table 3-1 shows which Multi-Net calls can interrupt
another type. For more information on Multi-Net
special calls, refer to Section 3.15.2.

3.14.4 CLEAR-TO-TALK FEATURE

The Clear-to-Talk (Proceed Tone) feature sounds
a short tone to indicate when speaking can begin when
transmitting a message. The clear-to-talk tone sounds
after the push-to-talk switch is pressed when the
system has been successfully accessed (handshake
completed). If a busy condition is encountered when
the push-to-talk switch is pressed, no busy or other
tone sounds and “BUSY” appears in the display (refer
to Section 3.22). If the push-to-talk switch is held
down, the system will be accessed when a repeater
becomes available. If an out-of-range or other error

condition occurs when the push-to-talk switch is
pressed, the intercept tone sounds instead (see Section

3.14.6).

The clear-to-talk feature is not a programmable
function, so it is always enabled whenever a Multi-Net
or LTR system is selected. This tone is active with all
types of Multi-Net and LTR calls described later.
However, it does not sound when a conventional
system is selected because no handshake with the
repeater occurs.

Either a single (standard), double (loud), or no
clear-to-talk tone can be selected. To toggle between
these states, turn power on with the “S” key pressed
(8560-8568) or select the menu mode described in
Section 3.12 (8585-8588).

3.14.5 TRANSMIT INHIBIT

This feature prevents the transmitter from keying
if the mobile being called is busy with another call. To
enable this feature, the Multi-Net or LTR system is
programmed with a block of transmit inhibit ID codes
that can include up to all 225 or 250. If a code within
this block is detected up to 5 seconds before the PTT
switch is pressed, the transmitter does not key, the
intercept tone sounds, and “TX INHIB” is displayed.

To make another call attempt, the PTT switch
must be released and then pressed again. The 5-second
timer does not count down while the PTT switch is
pressed, so it is not possible to complete the call by
holding the PTT switch down until the intercept tone
stops sounding.

One use of this feature is to prevent the acci­dental interruption of a call in progress. This could
happen when the other transmitting party unkeys or if
an ID code with a higher priority is transmitted.
Another use of this feature is to provide an indication
that the mobile being called is busy. A similar
Transmit Disable On Busy feature is available on
conventional systems.

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Table 3-1 Multi-Net Standard And Special Call Receive Priority

Interrupting Call

Call in Progress

Standard Group [1] [1] [1] Yes Yes Yes Yes Yes
Interconnect No No No No Yes Yes Yes Yes
Auxiliary No No No No No No Yes Yes
Interrogate NoNoNoNoNoNoYesYes
Kill No No No No No No Yes Yes
Reassignment NoNoNoNoNoNo--- --­Emergency NoNoNoNoNoNo ---Yes
All Call No No No No No No [2] -­[1] With these calls, the priority order is determined by the type of ID code as listed in Section 3.14.3.

[2] Since the “All Call” call goes out on all system repeaters, the emergency call is not sent until that call is
finished.

3.14.6 SUPERVISORY TONES

There are several supervisory tones that are heard
at various times when operating the transceiver. These
tones are as follows:

Intercept Tone - This is a siren-like tone consisting of
alternating 250 millisecond 1209 and 1864 Hz tones.
This tone indicates the following out-of-range or other
error conditions:

Sta nda rd

Group

• When this tone sounds when attempting to access

the system and “NO SITE” appears in the display,
the data handshake with the repeater could not be
completed. The usual cause of this is an out of radio
range condition. Six access attempts are made
before this tone sounds. Once it sounds, no more
access attempts are made until the push-to-talk
switch is released and then pressed again.

• If this tone sounds after the transmitter has been on

for an extended period and “TX TIME” appears in
the display, the transmitter has been disabled by the
Time-Out Timer feature. Refer to Section 3.5 for
more information.

Intercon-

nect

Auxiliary

Interro-

gate

programmed as receive-only. Refer to Section

3.21.2 for more information.

Clea r-To- Ta l k Ton e - This is a 50 millisecond burst
of the 697 Hz tone which sounds after the push-to-talk
switch is pressed to indicate when talking can begin.
Refer to Section 3.14.4 for more information.

Key Press Tone - This is a 50 millisecond burst of the
697 Hz tone that sounds to indicate when a key is
pressed. This tone can be enabled and disabled by
turning on power with the SCN key pressed.

Low-Battery Tone - This is a 50 millisecond burst of
the 1336 Hz tone that sounds when the battery needs
recharging. Refer to Section 3.9.3 for more
information.

Programming Tones - There are tones which sound
when a transceiver is programmed to indicate whether
or not proper programming occurred. Refer to Section

4.5 for more information.

Kill Reassign

MULTI-NET SPECIAL CALL TONES

Emer-

gency

All Call

• If this tone sounds as soon as the push-to-talk switch

is pressed and “TX DSBL” appears in the display, a
channel is selected in the conventional mode that is

Revised February 1997
Part No. 001-8560-381

NOTE: The following tones are produced by the
Multi-Net RNT and are heard only when placing
special calls.

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TRANSCEIVER OPERATION

Confirmation Tone - A short tone which sounds
when the number just dialed is accepted by the
system.

Call Proceed Tone - With Multi-Net Directed Group
calls, ringing does not occur after the number is
dialed. Instead, this short tone sounds after the confir­mation tone to indicate that the audio path is complete
and speaking can begin.

End Call Tone - Three beeps which sound when the
end of the call has been detected by the system.

Proceed Dialing Tone - When placing a landside­originate call to a mobile, the caller may dial the
number of the system and then when the system
answers, a number specifying the mobile being called.
This tone sounds to indicate when the number of the
mobile should be entered. Refer to Section 3.15.2 for
more information.

LTR TELEPHONE CALL TONES

NOTE: The following tones are produced by the LTR
RIC interconnect equipment and are heard only when
placing LTR telephone calls.

Reorder Tone - Three beeps which indicate that the
call has been terminated by the system.

Return Time Warning Tone - Two beeps which warn
that you have not transmitted for an extended period.
If you do not transmit within 5 seconds, the call is
automatically terminated by the system. The time
between transmissions is one of the parameters used
by the system to detect the end of a call when the #
character is not sent.

Conversation Time-Out Tone - Calls are limited to a
certain length by the system. Thirty seconds before
this time is reached, a “tick” begins sounding each
second. When the 30-second time expires, the call is
automatically terminated by the system.

Turn-Around Tone - This is a single beep which may
be used to indicate to the landside party when to
respond to your transmission. It sounds when you
release the PTT switch, and you may partially hear
this tone.

Proceed Tone - This tone consists of two beeps and it
tells the landside caller when to enter the five-digit
number specifying the mobile being called. Dialing of
this number must be started within 5 seconds of
hearing this tone, and a tone-type telephone must be
used.

3.15 MULTI-NET STANDARD AND SPECIAL CALLS

NOTE: The Multi-Net standard calls described in the
following information are also available with LTR
operation. However, the special calls are not available
except for a similar interconnect call.

3.15.1 STANDARD CALLS

Standard calls are between mobiles or groups of
mobiles which use the standard group ID codes from
1-225 (Multi-Net) or 1-250 (LTR) that are assignable
to each home repeater (see Section 2.3). Multi-Net and
LTR standard calls are very similar and are placed and
received using the same procedure. A standard call is
placed by simply selecting a group programmed with
the ID code of the mobile being called. No number is
dialed with a DTMF keypad as with telephone or
special calls.

To receive a standard call, the mobile must be
programmed to decode the ID code being transmitted.
With all Multi-Net calls, unique ID code information
is also transmitted with each call. However, it is not
decoded when receiving a standard call.

3.15.2 SPECIAL CALLS

Introduction

Standard and special calls can be placed and
received with Multi-Net operation. Standard calls
were described in Section 3.15.1. Special calls use the
special call group ID codes from 226-254. The special
calls typically originated by a mobile are Interconnect
(telephone) and Auxiliary. Most other special calls
such as Interrogate, Mobile Disable, and Reassign­ment are originated by the system operator or a
dispatcher. A transceiver with the optional DTMF
keypad and special programming are required to place

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special calls. The mobile-originated calls are
described in the following information.

Mobile-Originated Special Calls

Interconnect - These are telephone calls to or from a
mobile made through the Public Switched Telephone
Network (PSTN).

Auxiliary - These calls allow a mobile to communicate
with any individual mobile or group at the same site or
another Multi-Net site (when several Multi-Net sys­tems form a network). Calls to specific mobiles are
called Unique ID calls, and calls to specific groups are
called Directed Group calls. Directed Group calls allow
communication with groups that are otherwise not ac­cessible because no selectable system has been pro­grammed with the home repeater or group ID of those
mobiles. Directed Group calls can be made to any
home repeater on any group ID from 1-225.

Transceiver Programming For Special Calls

To originate a special call, the transceiver must
have one of its selectable group positions programmed
for the special call being made (Interconnect or Auxil­iary) as shown in the following chart. ID code 236
programs Auxiliary calls and ID code 237 programs
Interconnect calls. This chart also shows which ID
must be programmed to hear a response or receive a
special call. These IDs may be fixed or selectable as
described in Section 3.16.1.

Type of Ca ll

Interconnect Interconnect Interconnect

Auxiliary

Unique ID Auxiliary Auxiliary

Dir Group Auxiliary Group ID

Auxiliary Calls = ID Code 236; Interconnect (Telephone)
Calls = ID Code 237

Originating Mobile Receiving Mobile

Encode ID Decode ID

Note that with special Directed Group calls, the
Auxiliary ID is encoded to place the call, and the spec­ified group ID is decoded to receive the call. This is
because the call is converted to a standard group call
by the RNT. Also note that when a landside call is
made to a specific mobile, it is always classified as an
interconnect call even though the unique ID of the
mobile may be specified (refer to “Landside-Origi-
nated Calls” which follows).

Special Call Authorization

When a mobile is programmed to make Intercon­nect calls, system authorization is needed before
service is available. This authorization is performed
by the system operator through the System Manage­ment Module of the RNT, and it determines what type
of service is available. For example, a mobile may be
authorized to dial local numbers only. This authoriza­tion is keyed to the mobile’s unique ID which is trans­mitted when any call is made.

With all Auxiliary calls, all that is required is
proper programming of the mobiles originating and
receiving the call. Therefore, a Unique ID call can be
made to any mobile in the same site or some other site
that is programmed for Auxiliary calls. The same
applies to Directed Group calls except that the mobile
receiving the call does not need to be programmed for
Auxiliary calls, just the standard group ID being
transmitted.

Placing a Special Call

The following is the procedure for placing a
special call. As previously described, an optional
DTMF microphone is required to place a special call.

a. Select the group programmed for Interconnect or

Auxiliary calls, whichever is to be made. When an
interconnect group is selected, is displayed;
when a group programmed for unique ID calls is
selected, “

U” is displayed (858x only).

NOTE: When receiving special calls, ID codes 236
and 237 are treated like fixed codes even when they
are programmed as selectable codes. Therefore, calls
on those ID codes are detected regardless of which
group is selected or group scan programming (as long
as the system is selected or scanned).

Revised February 1997
Part No. 001-8560-381

b. Press the PTT switch and when the system is

accessed, the clear-to-talk (proceed) tone sounds (if
it is enabled). Release the PTT switch and a dial
tone should be heard. Successful accesses and busy
or out-of-range conditions are indicated as
described in Section 3.14.6.

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TRANSCEIVER OPERATION

c. If an interconnect call is being placed, dial the tele-

phone number of the landside party you are calling.

d. If a unique ID or directed group call is being made,

a 4-8 digit number is dialed which specifies the des­tination of the call. This number is entered the same
as with telephone calls. The digits dialed for the var­ious types of calls are as follows:

Unique ID Call (Current Site)

4-digit unique ID of mobile/dispatcher

Unique ID Call (Directed Site)

3-digit site ID +
4-digit unique ID of mobile/dispatcher

Directed Group Call (Current Site)

2-digit home repeater number +
3-digit group ID

Directed Group Call (Directed Site)
3-digit site number +
2-digit home repeater number +
3-digit group ID

e. Release the PTT switch if it was pressed to dial the

number. A beep should then sound which indicates
that the number was accepted by the system. If this
beep does not sound, an unauthorized number may
have been dialed or a dialing mistake may have
been made.

f. The various types of calls proceed as follows:

Interconnect Call - The normal landside ringing or
busy tone is heard. When the party answers, press
the PTT switch to talk and release it to listen as with
standard calls.

Unique ID Call - A “ringing” tone is heard which
indicates that the mobile is being rung. If there is no
answer, ringing stops after several rings or the call
can be terminated by pressing the # key. When the
party answers, press the PTT switch to talk and
release it to listen as with a standard call.

and release it to listen.

NOTE: Since this transceiver operates half-duplex,
you cannot hear the other caller while transmitting
or speak to the other caller while receiving.

g. When the call is finished, terminate it by pressing

the # key. This tells the system that the call is com­plete and prevents additional billing for the time
required to automatically detect the end of the call.

Receiving Special Calls

To receive a special call, all that is required is
that the system programmed for the special call be
selected (see “NOTE” earlier in this section). When an
Interconnect or Unique ID call is received, “ringing”
is heard. If it is a Directed Group call, only the voice
of the calling party is heard because no ringing occurs.

Landside-Originate Special Calls

Calls can be also be made from any landside tele­phone to specific mobiles (Unique ID calls) or groups
(Directed Group calls). Calls can also be placed to
other sites similar to when they are mobile dialed.

If the system has DID lines, the landside caller
can dial a mobile directly because each mobile that
can receive these calls is given its own phone number.
If the system has standard trunk lines, the telephone
number of the system is dialed. Then when the system
answers, a short tone sounds to indicate that the digits
specifying the destination of the call should be dialed.
The same digits are dialed as described in “Placing a
Special Call”. The landside telephone must produce
standard DTMF tones to dial these digits.

After these digits are dialed, a beep is heard
which indicates that the number was accepted by the
system. Ringing then indicates that the mobile is being
rung unless it is a Directed Group call. With those
calls, no ringing of the mobile occurs and another
beep is heard which indicates the path is complete and
speaking should begin.

Directed Group Call - A second beep sounds
which indicates that the path to the mobile is com­plete and speaking can begin (no ringing of the
other mobile occurs). Press the PTT switch to talk

After the mobile answers, the landside party
should respond in the normal manner. Remember that
the mobile is operating half duplex and cannot hear
the landside party while transmitting. When the call is

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finished, it should be terminated by the mobile party.
Three beeps indicate that the call has terminated.

3.16 EMERGENCY CALL OPERATION

3.16.1 INTRODUCTION

The general operation of Emergency Calls was
described in Section 2.8.11. The two basic operating
modes that can be programmed are Manual Transmit
and Automatic Transmit. Any type of system can be
programmed for Emergency Switch operation.
However, with LTR and conventional systems, only
the Manual Transmit mode is available.

When the Emergency switch is pressed, a beep
sounds to indicate to the user that the switch has been
pressed. The transceiver then looks at the emergency
call information programmed in the currently selected
system. If system scanning, it looks at the revert
system. If an emergency system/group is programmed
in that system, the transceiver changes to that system/
group. If none is programmed, the transceiver returns
to normal operation.

Operation from this point is controlled by
Manual/Automatic Transmit programming. The
following information describes operation in these
modes.

3.16.2 MANUAL TRANSMIT

In this mode, automatic transmissions do not
occur. However, the transceiver locks on the emer­gency system/group (other system/groups cannot be
selected), scanning is disabled, and all transmissions
occur at access priority 1 (except on LTR and conven­tional systems which do not use access priority). The
only calls received are those occurring on the emer­gency system/group or “all calls”. Calls on the select­able, fixed priority, and block ID codes of that system
are not received.

3.16.3 AUTOMATIC TRANSMIT

When the Emergency switch is activated with
Automatic Transmit programmed, system and group
selection and scanning are disabled and the transceiver
begins automatically transmitting the Emergency Alert
call. This call is transmitted on the programmed emer­gency system/group every 10 seconds using access
priority 1.

When the dispatcher receives the emergency call,
the mobile's unique ID and other information is
displayed on the console. The dispatcher then
acknowledges the call by transmitting the Emergency
Acknowledge call. When this call is detected by the
mobile, it halts automatic transmissions. However,
system and group selection and scanning remain
disabled until the emergency call sequence ends. In
addition, any further transmissions occur at the access
priority programmed for the group selected by the
emergency switch.

The emergency call sequence ends when the turn­off code is received or transceiver power is turned off
and then on again. If the push-to-talk switch is pressed
before the Emergency Acknowledge call is received,
the Emergency Alert transmissions continue only until
the push-to-talk switch is released.

3.17 AUTO-REGISTRATION

3.17.1 INTRODUCTION

Auto-registration was described briefly in Section

2.8.12. This feature permits telephone and unique ID
calls to be automatically routed to the site in which the
mobile is operating. Standard calls can also be routed
if the Site Tracking Module (STM) in the RNT is
configured appropriately. To utilize auto-registration,
“Auto Registration = Y” must be programmed and the
system scan mode must be selected by the SCN key.
Auto-registration does not occur when not scanning.

Other mobiles may also join in the conversation,
either by selecting the emergency mode or selecting
that system/group. In this case, all rules of normal
transmission and reception apply. To exit the emer­gency mode and resume normal transceiver operation
after the emergency call is completed, turn transceiver
power off and then on again.

Revised February 1997
Part No. 001-8560-381

Auto-registration effectively controls the revert
system when scanning (refer to Section 3.3.4). There­fore, it can be used with the “Last Selected” and
“Temporary” configurations, but not “Last Received”.

Upon entering the scan mode or if the signal from
the currently registered site is weak, the transceiver
begins checking all programmed status channels to

3-18

TRANSCEIVER OPERATION

locate one with suitable signal strength. When a
channel is located, a registration message is sent to the
repeater. The repeater then forwards the information to
the RNT. The location of the mobile is then known and
when a call to that mobile is placed, it is automatically
routed to the correct site.

When the mobile is searching for a site on which
to register, “SCN” flashes in the lower part of the
display (it is normally on constantly in the scan mode).
To maintain communication on a site regardless of
signal strength, simply turn scanning off by pressing
the SCN key. This permits communication with a
group in marginal signal conditions.

After registration, “SCN” is again displayed
continuously and the revert system is the next higher
system with a different site number that could be
accessed (wrap-around occurs after the highest system
is checked). For example, if System 3 was selected
and System 5 is the first system with a different site
number that could be accessed, that system becomes
the revert system. The revert group is the group that
was displayed before registration occurred.

3.17.2 SCANNING WITH AUTO-

REGISTRATION

If single-site scan is programmed (refer to
Section 3.3.2), only the site on which the transceiver is
currently registered is scanned. If multiple-site scan is
programmed, sites are scanned in the normal manner.
However, if LTR or conventional systems are
programmed in addition to Multi-Net systems, regis­tration occurs on only Multi-Net systems.

3.17.3 AUTO-REGISTRATION WITH 858X

QUICK SELECT SWITCH

If the quick select switch position is locked by
system operator programming, registration does not
occur even if the selected system is programmed for
auto-registration. If auto-registration was permitted,
the selected system may automatically change which
would defeat the purpose of having locked quick select
switch positions (see Section 3.11).

3.17.4 DROPOUT CRITERIA

messages received over a 10-second period. With the
8560-8568 transceivers, this percentage is set at 50%.
With 858x and later model mobile transceivers, it can
be programmed for 50-100% on each Multi-Net site.
The higher the percentage, the sooner auto-registration
occurs. Refer to Section 2.8.12 for more information.

3.18 BUSY QUEUING (MULTI-NET)

3.18.1 INTRODUCTION

Busy queuing places the call in a queue if the
system is busy when the PTT switch is pressed. Then
when the system becomes available, the user is alerted
by a tone and the call can be placed if desired. An
available system is determined in the normal manner
by the access priority of the selected group and the
current access priority being transmitted by the
repeater.

Since busy queuing is a transceiver parameter, it
is either enabled or disabled on all Multi-Net systems.
It is not available on LTR and conventional systems,
and it functions with both standard and special calls.
Busy queuing is referred to as “System Access
Queuing” on the programming screen.

When queuing has been programmed, the busy
tone sounds when the system is busy. (When queuing
is not programmed, no tone sounds because the clear­to-talk feature sounds a tone only when a successful
access is made.) System scanning is disabled while a
call is in queue. However, group scanning continues if
it has been programmed on the selected system.

The queue mode is entered automatically when
the PTT switch is released with the busy tone
sounding. The busy tone then stops sounding and the
word “QUEUED” is displayed in the unique identifi­cation area of the display.

When the system becomes available, the trans­ceiver waits a random time and then accesses the
repeater. This random delay minimizes the chance of
collisions with other mobiles in queue. If an access
attempt is unsuccessful, another access is attempted
after a random time delay. This continues until a
successful access is completed.

The point at which registration on another site is

triggered is controlled by the percentage of good data

When the access is successful, the user is alerted
by either a beeping tone or dial tone. The beeping tone

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is heard if a standard call is being made, and the dial
tone is heard if a special call such as interconnect or
auxiliary is being made. The call can then be placed in
the normal manner.

When the access is successfully completed by the
transceiver as described, the repeater hangtime indi­cator is set. This holds the repeater for the length of
the hangtime programmed by the System Management
Module. If no call is made by the user during this
hangtime, the queue mode is exited and the transceiver
returns to normal operation.

3.18.2 EXITING THE QUEUE MODE

When the queue mode is exited, the queue indica­tion turns off. The queue mode can be exited at any
time by momentarily pressing the PTT switch (except
when responding to a call on another group). It is also
exited if any of the following occur.

• A call is received on the selected group.

• The selected system or group is changed manually.

• The PTT or Emergency switch, or any key directly

below the display is pressed.

• A Reassign Select Command is received.

3.18.3 RECEIVING CALLS IN THE QUEUE

MODE

While in the queue mode, calls are received
normally. In addition, if group scanning is
programmed on the selected system, calls are received
on the other selectable groups. However, since system
scanning is temporarily disabled, calls are not received
on other programmed systems. If a call is received
while in queue, the user can respond to the call in the
usual manner and then normal queuing of a call
resumes shortly after the call is finished. The length of
the delay before queuing resumes is set by the receive
scan delay timer.

3.19 PHONE MODE

SEND keys. The phone mode is indicated when
“PHON” appears in the display. The phone mode
provides the following features to make the placement
of calls more convenient:

• The 5-digit group or 7-digit system identification is

cleared and the telephone number being dialed is
displayed.

• The SCN, LCK, and RTN keys become, respec-

tively, STO, CLR, and RCL keys.

• Numbers can be entered at any convenient rate and

then transmitted automatically when desired by
simply pressing the SEND key.

• Up to 8 (857x) or 7 (858x) 14-digit numbers can be

stored in memory and recalled as needed.

• System and group scan are disabled, so calls are

received on only the displayed system and group
(and also any priority or block decode codes if
programmed).

Telephone calls can also be placed without
selecting the phone mode by simply pressing the push­to-talk switch and dialing the number. However, since
the dialed number does not appear in the display, it
cannot be stored or recalled. When calls are received,
selection of the phone mode is optional because opera­tion is the same when is it not selected.

Although the phone mode is intended for use in
making Multi-Net and LTR telephone calls, it can also
be used in the conventional mode. The main difference
in operation is when the telephone number can be sent
using the SEND key. When a Multi-Net or LTR
system is selected, the dial tone must first be obtained
by briefly pressing the push-to-talk switch. The trans­ceiver detects the probable presence of dial tone by
detecting when receive audio is enabled. When a
conventional system is selected, the telephone number
can be sent at any time if a carrier is not present. If a
carrier is present, the SEND key is active only if the
receive audio is enabled. This ensures that any traffic
on the channel is monitored.

3.19.1 INTRODUCTION

When equipped with the optional keypad, the

phone mode can be selected by pressing the PHON or

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TRANSCEIVER OPERATION

3.19.2 ENTERING PHONE MODE

As stated earlier, the phone mode can be entered
by pressing the PHON or SEND keys. The operation
produced by these keys is slightly different as follows:

When the PHON key is used, the displayed
system and group do not change when the phone mode
is entered and exited. For example, if System 2/Group
4 were displayed before the phone mode is selected,
they would remain selected in the phone mode and
also after the phone mode is exited by again pressing
the PHON key (the PHON key is always used to exit
the phone mode).

When the SEND key is used to select the phone
mode, the system/group that have been preprogrammed
for telephone calls are automatically selected. Then
when the phone mode is exited by pressing the PHON
key, the system/group that were displayed before the
phone mode was entered are again displayed. The
system/group can be changed in either mode by
pressing the system or group select keys.

3.19.3 DIALING THE NUMBER

In the phone mode, dialing errors can be
corrected and then the number transmitted when
desired by pressing the SEND key. To erase the last
digit entered, press CLR (LCK). Holding the key
down causes the function to repeat. To erase the entire
number, press RCL CLR (RTN LCK).

This eliminates the need to re-enter frequently called
numbers. To store and recall a number, proceed as
follows:

1. Select the phone mode and enter the number as
described in the preceding information.

2. Press STO (SCN) and a number key from 1-8 or
1-7 to select the location where the phone number is
stored. The * can also be stored, but is sent normally
without a pause. The # should not be stored because
the call will be terminated when it is sent.

3. To recall a number, select the phone mode and press
RCL (RTN) and the location number from 1-8 or
1-7. The number then appears in the display and can
be changed if desired and then transmitted by
pressing SEND. When numbers longer than 7 digits
are recalled, digits 8-14 are flashed in the display
and then digits 1-7 are displayed continuously.

Any of the memory locations can also be dealer
programmed. If the number has less than 14 digits, the
unused digits can then be used to program a unique
identification or other information. For example, if the
telephone number has seven digits, the first seven
positions can be programmed with a non-numeric
identification such as “RICHARD”, and the last seven
positions can be programmed with the telephone
number. Then when this number is recalled,
“RICHARD” is flashed in the display followed by the
telephone number.

Numbers up to 14 digits in length can be entered
in the phone mode. However, only the last 7 digits are
displayed. To momentarily display the overflow digits,
press RCL 0. When more than 7 digits have been
entered, an overflow arrow appears on the left side of
the telephone number. It is possible to dial a number
without changing the number in the display. Simply
press the push-to-talk switch and dial the number. This
operation also allows special services to be accessed
which require that DTMF digits be dialed after the
connection is made.

3.19.4 STORING AND RECALLING TELEPHONE

NUMBERS FROM MEMORY

Up to eight (857x) or seven (858x) 14-digit
numbers can be stored in memory and later recalled.

When a dealer-programmed number is trans­mitted, all characters except 0-9, “*”, and “#” are
ignored. Therefore, various configurations of charac­ters can be programmed as long as the phone number
digits are in the correct order. Each dealer
programmed number is also programmed so that it
either may or may not be reprogrammed by the user. If
a dealer-programmed number is changed by the user,
any non-numeric identification is erased and can be
reprogrammed only by the dealer. Refer to Section

4.3.2 for more information on telephone number
programming.

The RCL key can also be used to step through the
programmed numbers. If RCL is pressed when the
display is blank, the number in location 1 is displayed.
Pressing it again displays the number in location 2 and

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so on. If a location contains more than seven charac­ters, the upper seven characters are displayed momen­tarily and then the lower seven characters are
displayed continuously. Therefore, to display only the
unique identification in each location, press the RCL
key rapidly (before lower characters are displayed). To
display the upper characters, press RCL 0.

3.19.5 TERMINATING A CALL

When a conversation is finished, one of the
parties making the call should terminate it by transmit­ting the # character. When the phone mode is exited by
pressing the PHON key, this character is sent automat­ically. This character can also be sent by pressing the #
key.

Transmitting the # character tells the RNT or LTR
interconnect equipment that the call is finished. If the
call is not terminated in this manner, the repeater or
repeaters being used will be held until a system timer
causes the call to be terminated automatically. Addi­tional billing also occurs during this time.

3.20 VOICE ENCRYPTION

When the optional voice encryption feature is in­stalled (see Section 1.2.7), it is controlled manually by
pressing 2ND OPT (RTN LCK) as described in
Section 3.13.8. Encryption is enabled when the f
symbol is displayed (or SCRAMBLE with the remote
control unit). When power is turned on, encryption
always reverts to the off mode.

encryption in the repeater must be disabled, it may still
be necessary to disable encryption before dialing a
number.

3.21 CONVENTIONAL SYSTEM OPERATION

3.21.1 CONVENTIONAL SYSTEMS AND GROUPS

Each group of a conventional system selects a
channel. With up to ten groups per system, this permits
up to 140 channels to be programmed with this trans­ceiver. Each channel can be programmed with Call
Guard squelch or standard carrier-controlled squelch.
Refer to Section 3.21.5 for more information on Call
Guard squelch.

3.21.2 TALK-AROUND AND RECEIVE-ONLY

CHANNELS

Each channel can be programmed as standard
(both receive and transmit), receive-only, or talk­around. If the push-to-talk switch is pressed with a
receive-only channel selected, the transmitter does not
key, the intercept tone sounds, and “TX DSBL” is
indicated in the display. If a channel is programmed as
talk-around, transmission is on the mobile receive
frequency. This permits mobile-to-mobile communica­tion when out of range of the repeater system. Talk­around is not available with Multi-Net or LTR
operation.

3.21.3 MONITORING BEFORE TRANSMITTING

Encryption is not programmable on a per system
or group basis with this transceiver. Therefore, it is not
automatically enabled or disabled when specific
systems or groups are selected and must be controlled
manually. Encrypted calls are always received regard­less of whether encryption is enabled or disabled.
However, encryption must be enabled to transmit an
encrypted call.

When making a telephone call, the DTMF tones
must always be transmitted non-encrypted. This is
necessary because encryption causes some tonal
distortion that may result in improper decoding.
DTMF tones are always transmitted non-encrypted
with this transceiver because the DTMF injection
point is after the encryption module. How-ever, if

Revised February 1997
Part No. 001-8560-381

When operating in the conventional mode, the
channel must be monitored before transmitting unless
it is done automatically as described in the next
section. If Call Guard squelch is not programmed, the
channel (group) can be monitored by simply listening
for someone talking before pressing the push-to-talk
switch. However, if Call Guard squelch is
programmed, it must be disabled so that all messages
on the channel can be heard. This is done by selecting
the monitor mode using the Auxiliary switch on the
side of the transceiver. The monitor mode is indicated
by “MON” in the lower part of the display.

A channel can also be monitored by noting if
“BUSY” is indicated in the lower part of the display.
This indication appears whenever there is a carrier

3-22

TRANSCEIVER OPERATION

present on the channel (group) being displayed. The
clear-to-talk and busy tones do not sound when a
conventional system is selected (refer to Section

3.14.4).

3.21.4 TRANSMIT DISABLE ON BUSY

The Transmit Disable On Busy feature prevents
the transmitter from keying if there is a carrier present
on the channel (“BUSY” indicated in the display).
This is a dealer-programmed transceiver feature that is
either enabled or disabled on all conventional systems.

When the transmitter is disabled by this feature,
the transceiver remains in the receive mode. As long
as the push-to-talk switch remains pressed, Call Guard
squelch is disabled so that any channel activity can be
monitored. In some systems, “BUSY” may be indi­cated and the transmitter disabled even though no one
is talking. If this is the case, the transmitter can be
keyed by releasing and then pressing the push-to-talk
switch again within 1 second. If the monitor mode is
selected by the Auxiliary switch (“MON” indicated in
display) or this feature has not been programmed, the
transmitter keys even if the channel is busy.

3.21.5 CALL GUARD SQUELCH

Introduction

Tone, digital, or inverted digital Call Guard
squelch can be programmed on each transmit and
receive channel in any order desired. There is also an
option to transmit a reverse burst or turn-off code on
transmit channels programmed with Call Guard
squelch. The reverse burst and turn-off code are
always detected by this transceiver on receive chan­nels programmed with Call Guard squelch. External
decoders are not supported by the Multi-Net version of
this transceiver.

Tone Call Guard Squelch

Tone-type Call Guard squelch utilizes subaudible
tones from 67-250.3 Hz. Although there are 38 tones
assigned, the top five are normally not used because of
their close proximity to the voice band which starts at
300 Hz. A reverse burst can be transmitted when the
push-to-talk switch is released to eliminate the squelch
tail (noise burst) in the receiving transceiver. However,
both the transmitting and receiving transceiver must be
equipped with this feature for it to be utilized. The
reverse burst is a 180-degree phase reversal for a
period of time determined by the tone frequency.

Digital Call Guard Squelch

Digital Call Guard squelch uses digital data
instead of subaudible tones to control the squelch. This
data consists of continuous repetitions of 23-bit words.
No bit or word synchronization information is used.
When the push-to-talk switch is released, a turn-off
code is transmitted which eliminates the squelch tail
similar to the reverse burst. Although there are thou­sands of possible code combinations with 23 bits, only
83 are unique with the data scheme used. The number
specified when the code is programmed is actually a
seed for a special algorithm used to generate the 23-bit
data word. The data is transmitted at a rate of 134.4
bits per second. Therefore, approximately six words
are transmitted each second. When the data is
decoded, 23-bit samples are taken and then the bits are
rotated to determine if a valid code was received.

Digital Call Guard squelch can be programmed as
normal or inverted. The only difference is that the
wave-form is inverted when “IDCG” is selected. The
inverted type may need to be programmed if the signal
is inverted by the repeater or another transceiver. If
digital Call Guard squelch does not function, try
changing to the other type.

The Call Guard squelch feature eliminates
distracting messages intended for others using the
channel. This is done by using a subaudible tone or
digital code to control the squelch. This tone or code is
unique to a user or a group on that channel. This tone
or code is transmitted with the voice signal but is not
heard because it is in the subaudible range and is atten­uated by a filter. Call Guard squelch must be used in
both the transmitting and receiving transceiver to be
functional.

3.22 DISPLAY MESSAGES

Various messages appear in the seven-character
system identification and telephone number area of the
display to indicate operating modes and error condi­tions. The messages that may be displayed are as
follows:

NO SITE - Indicates an out-of-range condition when
operating in the Multi-Net or LTR mode. Refer to

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TRANSCEIVER OPERATION

intercept tone description in Section 3.14.6 for more
information.

BUSY - Indicates that all repeaters are busy when a
Multi-Net or LTR system is selected. The conventional
mode BUSY indication is a separate indication which
appears in the lower part of the display (see Section

3.21.3).

TX TIME - Indicates the transmitter has been
disabled by the Time-Out Timer (see Section 3.5).

TX DSBL - Indicates that a receive-only channel is
selected in the conventional mode, so transmitting is
not allowed (see Section 3.21.2).

TX INHIB - Indicates that the selected group has been
detected as busy by the Multi-Net or LTR transmit
inhibit feature (see Section 3.14.5).

SYN ERR - Indicates that the frequency synthesizer is
out of lock (see Section 7.5).

PRG ERR - Indicates that no transmit frequency has
been programmed in the selected system (see Section

4.5).

RX PRI1 - Indicates that a call has been received on
the first priority ID code (see Section 3.14.3).

RX PRI2 - Indicates that a call has been received on
the second priority ID code (see Section 3.14.3).

IN SCAN - Indicates that system scanning is occur­ring (see Section 3.3).

KEYLOCK - Indicates that the keypad has been
disabled (see Section 3.9.1).

LOCKED - With 858xx transceivers, indicates that
the quick select switch position cannot be repro­grammed because it is locked by system operator
programming (see Section 3.11).

3.23 TEST MODE

accessory connector shorted together. To reselect the
normal mode again, turn power on without these pins
shorted together.

The transceiver operates as follows when the test

mode is selected:

System Select Key - Selects the 10 programmed test
channels. If no changes are made to the default test
channels, the channels shown in Table 3-2 are
programmed.

Group Select Key - Selects the following transmit
modulation types:

Group 1
(Used to set modulation balance.)

Group 2
(Used to set deviation.)

Group 3
phone.

Groups 4-10

DTMF Keypad - Operative at all times in test mode.

SCN Key - Toggles talk-around mode (“SCAN” in

display = talk-around mode).

Auxiliary Key - Pressing this key while transmitting
mutes microphone audio. The audio unmutes again
when the push-to-talk switch is released.

test mode:

: 134 Hz square wave; data filter bypassed.

: 134 Hz square wave; data filter utilized.

: No modulation other than from micro-

: Not used in test mode.

The following conditions are also present in the

• Receiver squelch is always controlled by the carrier.

• Holding the LCK key down when power is turned

on enables all segments of the LC display.

• The software version is displayed in place of a

unique system identification.

The transceiver has a test mode that is selected by

turning power on with the TxD and RxD pins of the

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Part No. 001-8560-381

3-24

Table 3-2 Default Test Channels

System Channel System Channel

117420

21208480

31809540

4 240 10 600

5 300 11-14 Not Select-

6360

able

TRANSCEIVER OPERATION

3-25

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TRANSCEIVER PROGRAMMING

SECTION 4 TRANSCEIVER PROGRAMMING

Figure 4-1 Programming Setup

4.1 GENERAL

4.1.1 PROGRAMMING SETUP

The following items are required to program this
transceiver. The part numbers of the RPI, cables, and
software are shown in Table 1-2 in Section 1. The
programming setup is shown above.

• IBM® PC or compatible computer

• E.F. Johnson Remote Programming Interface (RPI)

and interface cables

• E.F. Johnson transceiver programming software

4.1.2 COMPUTER DESCRIPTION

The transceiver programming software is
designed to run on an IBM PC or compatible
computer that meets the following minimum require­ments:

• 640K RAM

• MS-DOS

®

Version 3.0 or higher

• The program extracts into several files that require

a total of approximately 530K of disk space. There­fore, one of the following or better disk drive setups
is required:

– One 3½” or 5¼” (standard density) disk drive
and hard disk drive

– One of the above floppy disk drives and another
720K or greater disk drive

Although the program uses color to highlight
various types of information on the screen, a mono­chrome monitor also provides satisfactory operation.
Most IBM video formats are supported such as CGA,
EGA, and VGA. A serial port is required to connect
the RPI to the computer. One or two serial ports are
usually standard with most computers.

The cables between the RPI and computer and
transceiver are not included with the RPI. The latest

4-1

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RPI, Part No. 023-9800-000, has a female DB9
connector and earlier models such as 023-9750-000
and 023-5810-000 have a female DB25 connector.
Most computers have a male DB9 or DB25 serial
connector. Therefore, a M-F cable with DB9 or DB25
connectors is required to connect the RPI to the
computer. Suitable cables for this application and also
for connecting to the transceiver are listed in Table
1-2.

4.1.3 REMOTE PROGRAMMING INTERFACE (RPI)

The RPI provides the required electrical interface
between the computer and transceiver. It converts the
RS-232 logic levels of the computer to the TTL levels
of the transceiver and vice versa. The switch on the
RPI is used to turn power of a remote-mount mobile
transceiver on and off and also to select the flash
programming mode with later models. This switch can
be in either position for this application. The RPI has a
green indicator that lights when power is applied to the
transceiver and RPI.

system numbers above 14. Currently, the latest version
is 4.11 dated March 12, 1996. The 4.xx version
updates added Avenger SI/SK programming capa­bility. The screens shown in this section are from
Version 4.11.

This is a DOS program and therefore is designed
to run from the DOS operating system. If it is run from
within the Windows® 3.x, 95, or NT operating system,
it runs in the DOS mode. If the program does not run
correctly in Windows, exit Windows (3.x), select the
DOS mode (not DOS prompt) with Windows 95, or
reboot in the DOS mode (NT). The program is then
run from the DOS prompt (such as C:\>).

4.1.6 SOFTWARE INSTALLATION

When you receive the programming software,
make a backup copy and store the master in a safe
place. To make a copy of the distribution disk, use the
DOS copy command. For example, to copy all the
files on the disk in drive A: to the disk in drive B:, type
COPY A:*.* B:.

NOTE: Earlier RPIs, Part No. 023-9750-000 and 023­5810-000 can also be used to program this transceiver.
However, Part No. 023-5800-000 cannot be used.

4.1.4 EEPROM DATA STORAGE

The data programmed into the transceiver is
stored by an Electrically Erasable Programmable
Memory (EEPROM) on the transceiver logic board
(IC304). Since this type of memory is nonvolatile, data
is stored indefinitely without the need for a constant
power supply. Therefore, the battery can be removed
from the transceiver and it can even be stored indefi­nitely on a shelf without affecting programming. Since
an EEPROM is also reprogrammable, a new device is
not needed if reprogramming is necessary.

4.1.5 SOFTWARE DESCRIPTION

Besides programming the Multi-Net and LTR
85xx transceivers, the programming software is also
used to program the Avenger® SI/SK, 86xx mobile,
and 86xx remote control unit. Since this is a Multi-Net
transceiver, parameters referred to as “LTR Only” can
be ignored. In addition, some of these transceivers can
be programmed for more than 14 systems, so ignore

If you have a hard disk drive, you may want to
create a separate directory for programming. For
example, to create a directory called RADIOPRG on
drive C:, type C: to make it the current drive and then
MD \RADIOPRG (press ENTER after each
command). Then to change to that directory so that it
is the current directory, type CD \RADIOPRG.

The programming software is shipped in a
compressed format to allow it to fit on a 360K disk.
The name of the compressed file is TRUNK2.EXE,
and it unpacks into the following files:

Filename Approx. Size

TRUNKING.EXE 529K
CGINFO.WIN 3K
CRITERIA.WIN 1K
MHZ.WIN 1K
REVERT.WIN 2K
SYSINFO.WIN 3K
HELP.TXT 4K

The TRUNK2.EXE file is self extracting which
means that the files extract automatically when it is
executed. To extract these files so that the program can

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4-2

TRANSCEIVER PROGRAMMING

be used, first make the current directory the destina­tion directory for these files. For example, to make it
the \RADIOPRG directory on drive C: (if it is not the
current directory), type C: (Return) and then CD
\RADIOPRG as just described. To make it the disk in
drive B:, simply type B:. Then insert the program disk
in drive A: and type A:TRUNK2 (or B:TRUNK2 if
drive B: is being used). The program files are auto­matically extracted into the current directory or disk.

4.1.7 CONNECTING PROGRAMMING SETUP

Connect the programming setup as shown in
Figure 4-1. The transceiver is shipped from the factory
containing only test channels. After the RPI is
connected, turn transceiver power on. The green indi­cator on the RPI should light to indicate that power is
applied to the RPI.

4.1.8 STARTING PROGRAM

If your computer is running one of the Windows
operating systems, double click the icon for the
program. If the program does not run properly,
Windows must be exited and the program run from the
DOS prompt (see Section 4.1.5).

first time the program is run (if the desired configura­tion has been selected using the SETUP screen).

4.2 REMOTE CONTROL UNIT PROGRAMMING

When this transceiver is used with the optional
Vehicular Adapter (see Section 5), the remote control
unit may also be used. The remote control unit may
then need to be programmed. A different interface
cable is required between the RPI and control unit
(Part No. 597-2002-200). In addition, the Vehicular
Adapter system interface unit or junction box is
required to provide power to the control unit and RPI.

The transceiver programming software can also
be used to program the control unit. Simply select
“Multi-Net Control Unit” in the Select menu
described in Section 4.3.2. The control unit program­ming screen is shown below. The only control unit
parameters that may need to be programmed in this
application are the turn-off delay and horn alert key
enable/disable. The turn-off delay can be programmed
for 0, 10, 20, 30 minutes, 1, 2, or 4 hours, or infinite.
The factory-programmed time is 0 which causes the
transceiver to turn off immediately.

To run it from the DOS prompt, make sure the
current directory is the directory containing the
program (see preceding information) and then type
TRUNKING (the current directory should be the
directory containing the program and other files). On­screen prompts then instruct you how to proceed.

4.1.9 OPERATION WITH LCD SCREENS

With some computers (such as those with LCD
screens), information on the screen may be difficult to
see if the color mode is selected. Normally, the video
mode and other configuration information is specified
in the SETUP screen of the program (see Section

4.3.7). This information is then automatically saved to
a file called TRUNKING.CFG which is used by the
program to set the configuration the next time it is run.

However, this file is not present the first time the
program is run, so default conditions are used. If
required, the monochrome mode can be selected from
the command line by entering /L after TRUNKING
(TRUNKING /L). This should only be necessary the

The control unit can also be programmed with a
ten-character identification for each group. However,
this identification is not used because the control unit
always displays the seven-character identification
indicated by the transceiver. The control unit identifi­cation is not used because different transceivers with
different programming may be used with the same
control unit. Refer to the Vehicular Adapter Service
Manual, Part No. 001-5810-501, for more program­ming information.

4-3

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TRANSCEIVER PROGRAMMING

Figure 4-3 Select Menu

Figure 4-2 Main Menu

4.3.2 SELECT MENU

The Select menu shown Figure 4-3 is used to
select the transceiver to be programmed. Move the
highlight bar to “8560/65/70 Series” or “8585/8590
Series”, whichever is being programmed, and then
press Enter.

4.3.3 EDIT MENU

4.3 MAIN MENU PARAMETERS

4.3.1 INTRODUCTION

The opening screen indicates the version number
of the programming software. Press Enter from the
opening screen to go to the Main Menu shown in
Figure 4-2. Various screens can then be selected from
the menu bar on the top. Use the arrow keys to select
the desired menu (mouse operation is not supported)
and then select it by pressing Enter. Help menus can
be displayed by pressing F1. Error or warning
messages are displayed if a parameter is entered that is
not within the allowed limits.

When the program starts, the file
TRUNKING.DAT is always loaded. This file contains
the parameters that were selected the last time the
program was run. Information is written to this file
when the program is exited by selecting QUIT.

NOTE: To save the current configuration to a disk file
so that it can be recalled, use the FILES menu “Write
Configuration To File” function (see Section 4.3.6).

The EDIT menu shown above is used to enter the
various types of programming data. The parameters in
this menu are as follows:

Edit/Clear Current Worksheet

Normally, the parameters selected in the last
programming session are displayed (see Section 4.3.1)
when the program is started. “Edit Current Work­sheet” selects the radio and system/group parameter
programming screen without clearing the parameters.
Selecting “Clear Worksheet” erases all information in
the current worksheet and sets some parameters to
default conditions. Information programmed in this
screen is described in Section 4.5.

Edit Multi-Net UID

To display a DOS shell, select “Temporary Exit
To DOS” in the FILES menu. This allows DOS
commands to be executed without exiting the
program. The following information describes the
screens that are selected from the main menu.

Revised February 1997
Part No. 001-8560-381

This screen follows and it is used to edit the
unique ID code and group alpha tags that are
programmed for each system. This screen allows this
information to be edited without having to individu­ally display each system screen.

4-4

Edit Test Channels

When the data is programmed into the trans­ceiver, ten test channels are also programmed. The
default test channels are automatically programmed
unless they are changed using the “Edit Test Chan­nels” screen shown below. Refer to Section 3.23 for
more information on test channels and the test mode.

TRANSCEIVER PROGRAMMING

Edit/Clear Phone Numbers

This screen is shown below and it is used to
program the seven (858x) or eight (856x) telephone
numbers that can be recalled from memory in the
Phone Mode. If “Write Protect = Y”, the number
cannot be reprogrammed by the user. Refer to Section

3.19 for more information on programming these
numbers.

Edit/Clear Quick Select Assignments (858x Only)

This screen follows and it is used to program the
quick select switch positions. If the transceiver has a
telephone keypad, these positions can be repro­grammed by the user if “Lock = N”. Refer to Section

3.11 for more information.

Edit Auto-Registration Criteria (858x Only)

This screen is shown below and it is used to
program the number of good data messages that must
be detected to stay on the current site with auto-regis­tration. The higher the percentage, the sooner auto­registration occurs. Refer to Section 3.17 for more
information.

4.3.4 RADIO INTERFACE MENU

The RADIO INTERFACE menu which follows
is used to perform the actual programming of the
transceiver and also read programming data from a
transceiver. When Fast Write is selected, some
prompts are not shown and writing begins immedi-

4-5

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TRANSCEIVER PROGRAMMING

ately. One time when this menu is selected is to
program the transceiver after all required information
has been entered in the Edit Worksheet screen. When
the transceiver is in the programming mode,
“PROGRAM” is displayed.

4.3.5 SYSTEM MENU

The SYSTEM menu shown below is used to

copy, read, print, or delete a system configuration.

Copy a System

- An existing system is copied to
another system. For example, the data in System 2 can
be copied to System 5. The information in that system
can then be edited. This allows similar systems to be
set up without having to re-enter all the data.

Read a System From a Stored File

- A system stored in
a disk file is copied to a current system. A directory
listing can be displayed if desired by pressing F2 after
this function is selected.

Read Configuration

- Copies all the configuration data
from a disk file. This can be used to duplicate an
existing file so that it can be edited. A directory listing
can be displayed by pressing F2 after this function is
selected. A different directory can be specified if
desired.

Write Configuration

- Saves the current configuration
information to a disk file. The program prompts for a
file name. Up to eight characters and a three-character
extension can be entered (xxxxxxxx.xxx). A directory
listing can be displayed by pressing F2. A different
directory can be specified if desired. This operation
must be performed if you want to recall the file for use
at a later date. The current parameters are also saved to
a file called TRUNKING.DAT (see Section 4.3.1).

NOTE: Total files in the default directory are limited
to 100.

Print Current Configuration

- Prints the current config­uration information to a printer or disk file. Configura­tion information for a single system can be printed
using the SYSTEM menu “Print a System” function
described in the preceding section.

Print a System

- Prints the data programmed in the
specified system. If you want to print the entire config­uration including radio parameters and all system/
groups, use the FILES menu described in the next
section.

Delete a System

- Deletes data in the specified system

and returns it to the “Not Used” status.

4.3.6 FILES MENU

The FILES menu which follows is used to read,
write, or print a configuration file. It is also used to
temporarily shell to DOS. These functions operate as
follows:

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Part No. 001-8560-381

Temporary Entry to DOS

- Displays the DOS
command line without having to exit the program.
This allows DOS commands to be executed such as
file copies, directory listings, and disk formatting. To
return to the program, type EXIT.

4.3.7 SETUP MENU

The SETUP menu which follows is used to select
the serial port, display prompts, and video mode.
Information selected in this menu is stored in a file
called TRUNKING.CFG that is automatically loaded
the next time the program is run.

4-6

COM Port - This selects the serial port that is used by
the RPI. If the mouse is connected to COM1:, you
may want to use COM2: for the RPI. The serial port
may also be specified on the command line when the
program is run by typing /C1 (for COM1:) or /C2 (for
COM2:) after TRUNKING.

Display Prompts

- This turns the display prompts on
and off. These are prompts that request certain actions
be confirmed before they are executed such as when
exiting a level or the program. Prompts can also be
turned off on the command line by typing /N after
TRUNKING.

TRANSCEIVER PROGRAMMING

4.4 PROGRAMMING RADIO PARAMETERS

The parameters that are the same for all systems
are programmed by the radio parameters screen shown
in Figure 4-4. This screen is displayed by selecting the
“Edit Current Worksheet” function of the EDIT menu
(see Section 4.3.3). The parameters programmed in
this screen are described in Table 4-1.

Systems to be programmed are also selected from
this screen. Press the F3 key to move the cursor to the
system part of the screen and then select the system to
be programmed. When a “Not Used” system is
selected, the following screen is displayed to select the
system type. To change a system to “Not Used”, select
the SYSTEM menu and the “Delete a System” func­tion (see Section 4.3.5).

Color or Monochrome Display

- Selects either the
color or monochrome video mode. Some laptop
computers may not display information properly
unless the monochrome mode is selected. To select the
monochrome video mode from the command line,
type /L after TRUNKING (see Section 4.1.9 for more
information).

NOTE: The LTR/Multi-Net Console parameters do not
apply to this transceiver.

Figure 4-4 Radio Parameters Screen

4-7

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Figure 4-5 Multi-Net System Programming Screen

4.5 PROGRAMMING SYSTEM AND GROUP PARAMETERS

4.5.1 INTRODUCTION

When a Multi-Net, LTR, or conventional system
is selected as described in the preceding section, the
appropriate programming screen is displayed so that
the system parameters can be edited. The figure and
table which describes each of these screens is as
follows:

Multi-Net - Figure 4-5, Table 4-2
LTR - Figure 4-6, Table 4-3
Conventional - Figure 4-7, Table 4-4

4.5.2 REPEATER NUMBER PROGRAMMING

Each Multi-Net repeater site can have up to 30
repeaters, and each LTR repeater site can have up to
20 repeaters. The repeaters at the same site are
assigned a unique number from 1-30 or 1-20. With
Multi-Net systems, they can be assigned arbitrarily as
long as no two repeaters have the same number.

With LTR systems, they can also be assigned
arbitrarily. However, for maximum system efficiency,
a scheme should be used that equalizes, as much as
possible, the gaps between numbers. For example, a
five-repeater system should use numbers 1, 5, 9, 13,
and 17.

4.5.3 CHANNEL NUMBER PROGRAMMING

With LTR operation, the transceiver is
programmed with the channel number of each repeater
it can access. With Multi-Net operation, this is not
necessary because the transceiver receives “goto”
channel information over the air. The only channels
that are programmed in Multi-Net systems are the
home and status channels. This allows repeaters to be
added to the system without reprogramming the
mobiles.

Each system can be programmed with a different
home repeater if desired. However, Multi-Net systems
with the same site number must be programmed with
the same status channel number. Refer to Section 2.3
for more information on site numbers.

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4-8

TRANSCEIVER PROGRAMMING

Figure 4-6 LTR System Programming Screen

Figure 4-7 Conventional System Programming Screen

4-9

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The channel numbers used to program this trans­ceiver are listed at the end of this section. Be sure to
use the programming channel number and not the FCC
channel number. Programming channel numbers 1-600
are the same as the FCC channels, but some channels
above 600 are not the same. A –12.5 kHz offset can be
specified for channels 1-600 because they have a 25
kHz increment. However, channels above 600 have a

12.5 kHz increment, so the 12.5 kHz offset does not
apply.

4.5.4 ACCESS PRIORITY PROGRAMMING

(MULTI-NET ONLY)

Each Multi-Net encode (transmit) ID code is
programmed with an access priority number from 1-5.
As stated in Section 2.8.2, this access priority and the
current system priority being transmitted by the
repeater determine if the system can be accessed. If the
priority number being transmitted is greater than the
priority number assigned to the ID code being trans­mitted, the system cannot be accessed at that time.
There are various schemes that the repeater may use to
determine the current system priority. Refer to the
setup section of the repeater service manual for more
information.

4.5.5 SITE NUMBER PROGRAMMING

(MULTI-NET ONLY)

Each Multi-Net site must be assigned a number
from 1-255. A repeater site is defined as a group of
repeaters which share the same high-speed data bus
(see Section 2.6). The site number programmed in the
mobile is used for controlling scanning. A site number
is also transmitted in the form of DTMF tones when a
special call is made by a mobile to a different site. The
System Management Module Uses the site informa­tion to route the call. Refer to Section 3.15.2 for more
information on special calls.

If there is only one site that can be accessed by
the mobiles, the site number of the repeater system can
be selected arbitrarily. Each selectable Multi-Net
system of the mobile is then programmed with that site
number. If there are several sites that can be accessed,
each site must be assigned a unique number. Each
selectable system of the mobile is then programmed

with the number of the site that is accessed by that
system.

4.5.6 SPECIFYING RIC-EQUIPPED REPEAT­ERS (LTR ONLY)

When programming the channel numbers of LTR
systems, you can specify if the repeater is equipped
with E.F. Johnson RIC (repeater interconnect). If a
system with a transmit ID code programmed for RIC
telephone calls is then selected, the transceiver will
attempt to access only repeaters specified as equipped
with repeater interconnect. This allows both intercon­nect and non-interconnect equipped repeaters to be
programmed in each system.

Without this feature, the transceiver may trunk to
a repeater not equipped with an interconnect controller
when a telephone call is made. No dial tone or other
supervision is then returned when the PTT switch is
pressed which may be confusing to the user.

4.6 PROGRAMMING ERRORS

When proper transceiver programming has
occurred, a steady 697 Hz tone sounds. However, if an
error occurs while programming is taking place, a
busy tone sounds and MON or BUSY is displayed in
the lower part of the display, and the system and group
displays indicate the page and subpage on which the
error occurred. The two types of errors that may be
indicated are as follows:

EEPROM Error

- If an error is detected when the data
written to the EEPROM is checked, MON is displayed.
Try repeating the programming procedure. If an error
occurs again, the EEPROM is probably defective.

Communications Error

- If the communications path is
interrupted while programming is occurring, checksum
information in the data indicates an error. This error is
indicated by BUSY in the display. Check the program­ming setup cables and repeat the programming
procedure.

NOTE: Error messages that are displayed by the
program are also described in Appendix A.

Revised February 1997
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4-10

TRANSCEIVER PROGRAMMING

4.7 PROGRAMMING ONE TRANSCEIVER WITH ANOTHER (CLONING)

a. With both transceivers turned off, connect replica-

tion cable, Part No. 023-5810-013, between the
accessory connectors of each transceiver.

One transceiver can be used to program another
of the same type with identical information. One use
of this programming method is to program trans­ceivers in the field when a computer is not available.
This method of programming is slightly slower than
using a computer.

Proceed as follows to program one transceiver
with another:

b. Turn the receiving (slave) transceiver on first. Then

turn the transmitting (master) transceiver on with
the AUX button on the side pressed. Both transceiv­ers should then display “PROGRAM” as program­ming begins.

c. The system and group display indicate the page and

subpage as memory is programmed. When pro­gramming is complete, a beep sounds. Turn both
transceivers off and remove the replication cable.

Table 4-1 Radio Parameter Description

Parameter Acceptable Responses Description

Frequency Band 800 or 900 MHz 856x/858x = 800 MHz

Return Hang Time 1-7 seconds; 8 = infinite [1] Sets the length of time the home or last active system/group is dis-

played when the HOME key is pressed (see Section 3.8).

Call Delay Timer 1-7 seconds; 8 = infinite [1] Sets the delay that occurs before scanning resumes after transmit-

ting a message (see Section 3.3.3).

Receive Delay Timer 1-8 seconds; 8 = infinite [1] Sets the delay that occurs before scanning resumes after receiving a

message (see Section 3.3.3). In addition, with later model 858x
transceivers, programming “8” selects an 8-second delay the Last
Received revert (see Sections 3.3.3 and 3.3.4).

Transmit Time-Out 0.5-5.0 minutes in 0.5 minute

increments

Home System/Group Any programmed system/

group

RTN (Return) Option L = Last Selected

H = Home

Conv Tx Disable on Busy Yes, No “Yes ” programs the Transmit Disable On Busy feature on all con-

Auxiliary Tone Enable Yes, No Enables or disables the tone that sounds when the Auxiliary switch

MULTI-NET OPTIONS [2]

NOTE: The “LTR Options” do not apply to the Multi-Net version of this transceiver.

Phone System/Group Any Multi-Net or LTR system/

group that is programmed for
telephone calls (conventional
groups are not allowed)

Group Alpha Tag Yes, No Programs if group alpha tags are to be displayed on Multi-Net

Programs the Time-Out Timer (see Section 3.5).

Programs the system/group that is selected by the RTN key if the
RTN Option parameter which follows is programmed for Home
function (see Section 3.8).

Programs the system/group that is selected when the RTN key is
pressed (see Section 3.8).

ventional systems (see Section 3.21.4).

on the side is pressed. This is programmable only with 858x mod­els. It is always enabled with 856x models (see Section 3.2.1).

Programs the telephone system/group that is automatically selected
when the Phone Mode is enabled by pressing SEND key (see
Section 3.19). NOTE: Version 4.00 programming software incor-

rectly allowed only Multi-Net groups to be entered.

systems instead of system alpha tags. System alpha tags are always
displayed on LTR and conventional systems (Section 3.2.2).

4-11

Revised February 1997

Part No. 001-8560-381

TRANSCEIVER PROGRAMMING

Table 4-1 Radio Parameter Description (Continued)

Parameter Acceptable Responses Description

Fixed Revert Yes, No Programs if the revert system/group is Temporary (No) or Last

Selected (Yes) when scanning. With 858x models, to program
“Last Received”, see “Receive Delay Timer” parameter above. The
Fixed Revert programming is then ignored (Section 3.3.4).

Scan Mode M = Multi-Site

S = Single Site

Kill Setting Disallowed, w/interrogate, w/o

interrogate

Auto-Registration Yes, No Programs if auto-registration occurs while scanning (Section 3.17).

System Access Queuing Yes, No Programs if busy queuing is enabled on Multi-Net systems

System No./Type Multi-Net/LTR - standard or

with group scan, Conven­tional, Unused

[1] The “Infinite” setting is not available with 858x transceivers.

Programs the type of system scanning that is used (Section 3.3.2).

Programs if the mobile can be disabled by the SMM. If it can, also
programs if it can be interrogated after disabling (Section 2.8.5).

(Section 3.18).

Selects the system to be programmed. To change the system type,
press F2 with the system selected. The alpha tag is programmed in
the system screen (Section 4.4).

Table 4-2 Multi-Net System Parameters

Parameter Acceptable Responses Description

Mode M-Net or LTR (with or with-

out group scan), Conventional,
Unused

Alpha Tag (System) Uppercase A-Z, 0-9, – + * ( ) / Programs the unique 7-character system identification. This is not

Home Repeater 1-30 Programs the number of the repeater to which the transceiver is

Key --- This is a unique number supplied to the system operator by

UID (Unique ID) 1-8163 Programs the unique ID of the mobile (Section 2.8.1). This can

Status Channel No. 1-840 (800 MHz)

1-479 (900 MHz)

Site ID 1-255 Programs the site number of the system (Section 4.5.5).

Home Channel No. 1-840 (800 MHz)

1-479 (900 MHz)

Offset (-12.5 kHz) Yes, No Programs if channels are offset 12.5 kHz on the low side. This can

Emergency Switch System/Group, Automatic -

Y/N

Identifies the type of system that is programmed. To change the
system type, go to the Radio Parameters screen and press F2 with
the system selected. For information on group scan, see Section

3.4.

displayed by the transceiver on Multi-Net systems if Group Alpha
Tag were selected in Radio Parameters screen (Section 3.2.2).

assigned (Section 4.5.2).

Transcrypt (Section 2.8.9).

also be programmed using the “Edit Multi-Net UID” screen
(Section 4.3.3).

Programs the channel number of the status repeater (Section 2.3).
Channel numbers are shown in the table at the end of this section.

Programs the channel number of the home repeater (Section 2.3).
Channel numbers are shown in the table at the end of this section.

be programmed on 800 MHz channels 1-600 only (Section 4.5.3).

Programs the operation of the Emergency switch (Section 3.16).

Revised February 1997
Part No. 001-8560-381

4-12

TRANSCEIVER PROGRAMMING

Table 4-2 Multi-Net System Parameters (Continued)

Parameter Acceptable Responses Description

Transmit Inhibit Block 1-225 Programs the transmit inhibit block of ID codes (up to all 225). If a

code within this block is decoded up to 5 seconds before the PTT
switch is pressed, the transmitter does not key (Section 3.14.5).

Block Decode 1-225 Programs a block of ID codes (up to all 225) that are decoded

regardless of the group selected (Section 3.14.2).

Fixed Priority 1/2 1-225, 236, 237 [1] Programs the Fixed Priority 1 and 2 decode codes if they are used

(Section 3.14.3).

Call Light Yes, No Programs if Call indicator is enabled when the code is detected on

the ID code (Section 3.6).

Horn Yes, No Each of the fixed priority decode ID codes can be programmed to

enable the horn alert when the Vehicular Adapter and Remote
Control Unit are used (Section 3.7).

Data Priority Group N/A This feature is not available with this transceiver.

GROUP INFORMATION

Alpha Tag (Group) Uppercase A-Z, 0-9, - + * ( ) / Programs the unique five-character group identification. This is

displayed only if group alpha tags were enabled in the Radio
Parameters screen (Section 3.2.2). This can also be programmed
using the “Edit Multi-Net UID” screen (Section 4.3.3).

Selectable
Groups (1-11)

Priority (Tx) 1-5 Each of the selectable encode codes must be programmed with an

Call Light Yes, No Each of the selectable decode ID codes can be programmed to

Horn Yes, No Each of the selectable decode ID codes can be programmed to

[1] 236 = Auxiliary calls, 237 = Telephone (Interconnect) calls. Refer to Section 3.15.2 for more information.

1-225, 236, 237 [1] Programs the selectable decode (receive) and encode (transmit)

IDs (Section ). Both IDs in a group must be programmed.

access priority. “1” is the highest priority and “5” is the lowest pri­ority (Section 2.8.2).

enable the Call indicator (Section 3.6).

enable the horn alert when the Vehicular Adapter and Remote
Control Unit are used (Section 3.7).

Table 4-3 LTR System Parameter Description

Parameter Acceptable Responses Description

Mode LTR standard, LTR with group

scan, Conventional, Unused

Alpha Tag Uppercase A-Z, 0-9, – + * ( ) / Programs the 7-character system alpha tag that is displayed

Home Repeater 1-20 Programs the number of the home repeater to which the transceiver

Area 0, 1 Selects the area of the LTR repeater system. This is usually 0

Scan Weighting Not applicable This LTR feature is not used or needed with the Multi-Net version

Identifies the type of system that is being programmed. To change
the system type, go to the Radio Parameters screen and press F2
with the system selected.

(Section 3.2.2).

is assigned (see Section 4.5.2).

unless two systems are close enough to interfere with each other.
One system then uses 0 and the other uses 1.

of this transceiver.

Revised February 1997

4-13

Part No. 001-8560-381

TRANSCEIVER PROGRAMMING

Table 4-3 LTR System Parameter Description (Continued)

Parameter Acceptable Responses Description

Repeater Interconnect
(RIC) ID Code Block

Transmit Inhibit Code
Block

Block Decode Code
Block

Emergency System/Group
Auto-Tx

Fixed Priority ID codes Priority 1 = 1-250

Call Light Yes, No Programs if the call indicator lights when a call is received on that

Horn Yes, No Each of the fixed priority decode ID codes can be programmed to

Data Priority N/A This feature does not apply to this transceiver.

Repeater/Channel Num­bers

Selectable Group ID
Codes

Transpond Not applicable This LTR feature is not available with the Multi-Net version of this

1-250 Programs the block of ID codes (1 up to all 250) that are used for

RIC telephone calls. If an ID code within this block is detected
when receiving or transmitting, the transceiver enters the RIC
operating mode and calls can be placed and received.

1-250 Programs the transmit inhibit block of ID codes (1 up to all 250). If

the PTT switch is pressed within 5 seconds of detecting an ID code
within this block, the transmitter does not key (Section 3.14.5).

1-250 Programs the block of ID codes (up to all 250) that are decoded

regardless of the group that is selected (see Section 3.14.2).

System/Group ID, Auto Tx ­Y/N

Priority 2 = 1-250

Repeater No. = 1-20
Channel No. = 1-920

Groups = 1-10
ID codes = 1-250

Programs the operation of the Emergency switch. Only manual
operation is available in the LTR mode, so Auto Tx is always “N”
(Section 3.16).

Programs the Fixed Priority 1 and 2 ID codes if they are used
(Section 3.14.3).

priority ID code (Section 3.6).

enable the horn alert when the Vehicular Adapter and Remote
Control Unit are used (Section 3.7).

Programs the channel number of each repeater that can be accessed
(the offset applies only to 800 MHz channels 1-600). Also pro­grams if it is RIC-equipped. Channel numbers are shown at the end
of this section (Sections 4.5.3 and 4.5.6).

Programs the encode (transmit) and decode (receive) ID code for
the selectable groups. Up to ten groups can be programmed, and
the encode and decode IDs for each can be different. Both codes
for each group must be programmed (Section ).

transceiver.

Revised February 1997
Part No. 001-8560-381

4-14

TRANSCEIVER PROGRAMMING

Table 4-3 LTR System Parameter Description (Continued)

Parameter Acceptable Responses Description

Call Light Yes, No Each of the selectable decode ID codes can be programmed to

enable the call indicator (Section 3.6).

Horn Yes, No Each of the selectable decode ID codes can be programmed to

enable the horn alert when the Vehicular Adapter and Remote
Control Unit are used (Section 3.7).

Table 4-4 Conventional System Parameter Description

Parameter Acceptable Responses Description

System Type LTR standard, LTR with group

scan, Conventional, Unused

Alpha Tag Uppercase A-Z, 0-9, – + * ( ) / Programs the 7-character system alpha tag that is displayed when

Group No./ Channel No. Group = 1-10

Channel = 1-479

Rx CG Type None, CG, DCG, IDCG Programs the type of receive (decode) Call Guard squelch for that

CG = Tone (CTCSS), DCG = Digital (CDCSS), IDCG - Inverted digital

Rx CG Value Tone number or digital code If CG was selected, the tone number from 1-38 is entered. If digital

Tx CG Type None, CG, DCG, IDCG Programs the type of encode (receive) Call Guard squelch for that

Tx CG Value Tone number or digital code If CG was selected, the tone number from 1-38 is entered. If digital

Tx Disable Yes, No If “Yes ” is programmed, the group is receive-only and transmitting

Send Turnoff Yes, No If “Ye s” is programmed, the Call Guard squelch turn-off code is

Identifies the type of system that is being programmed. To change
the system type, go to the Radio Parameters screen and press F2
with the system selected.

the system is selected (Section 3.2.2).

Programs the channel number for the selectable groups being used.
The –12.5 kHz offset does not apply to 800 MHz channels above
channel 600 (Section 4.5.3). Channel numbers are shown at the end
of this section.

group (Section 3.21.5).

was selected, the digital code is entered. These numbers are listed
in Table 4-5 or they can be displayed by moving the cursor to
“Va lu e” and pressing F1.

group (Section 3.21.5).

was selected, the digital code is entered. These numbers are listed
in Table 4-5 or they can be displayed by moving the cursor to
“Va lu e” and pressing F1.

is disabled (Section 3.21.2).

transmitted when the PTT switch is released (Section 3.21.5).

4-15

Revised February 1997

Part No. 001-8560-381

TRANSCEIVER PROGRAMMING

Table 4-4 Conventional System Parameter Description (Continued)

Parameter Acceptable Responses Description

Talk-Around Yes, No If “Ye s” is programmed, transmitting occurs on the receive fre-

quency (Section 3.21.2).

Call Light Yes, No Each of the selectable groups can be programmed to enable the call

indicator (Section 3.6).

Horn Yes, No Each of the selectable groups can be programmed to enable the

horn alert when the Vehicular Adapter and Remote Control Unit
are used (Section 3.7).

Emergency System/Group
Auto-Tx

Data Priority Grp Position N/A This feature does not apply to this transceiver.

System/Group ID, Auto Tx ­Y/N

Programs the operation of the Emergency switch. Only manual
operation is available in the conventional mode, so Auto Tx is
always “N” (Section 3.16).

Table 4-5 Call Guard Codes and Tones

Tone Call Guard Codes

Code Freq Code Freq Code Freq Code Freq Code Freq

00 00.0 08 88.5 16 114.8 24 151.4 32 203.5

01 67.0 09 91.5 17 118.8 25 156.7 33 210.7

02 71.9 10 94.8 18 123.0 26 162.2 34* 218.1

03 74.4 11** 97.4 19 127.3 27 167.9 35* 225.7

04 77.0 12 100.0 20 131.8 28 173.8 36* 223.6

05 79.7 13 103.5 21 136.5 29 179.9 37* 241.8

06 82.5 14 107.2 22 141.3 30 186.2 38* 250.3

07 85.4 15 110.9 23 146.2 31 192.8

* These tones normally are not used because of their close proximity to the voice frequencies.
** This tone is normally is not used because it may cause interference with adjacent tones.

Recommended Digital Call Guard Codes

023 065 131 172 261 346 431 532 654 743

025 071 132 174 263 351 432 546 662 754

026 072 134 205 265 364 445 565 664

031 073 143 223 271 365 464 606 703

032 074 152 226 306 371 465 612 712

043 114 155 243 311 411 466 624 723

047 115 156 244 315 412 503 627 731

051 116 162 245 331 413 506 631 732

054 125 165 251 343 423 516 632 734

Revised February 1997
Part No. 001-8560-381

4-16

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

SECTION 5 BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

5.1 BATTERY PACK

CAUTION

Dispose of these nickel-cadmium batteries in accor­dance with local regulations. Do not dispose in a
landfill. Do not incinerate because an explosion may
result.

5.1.1 GENERAL

Standard 1400 mAH Battery Pack, Part Number
587-8565-171, contains six size Af nickel-cadmium
(Ni-Cd) batteries connected in series. Also inside the
pack are a diode, thermistor, and resistor (refer to
Figure 5-1). Diode CR1 protects against reverse
polarity when charging and also prevents discharge of
the battery through the charger. Thermistor RT1 is
used by the rapid and vehicular chargers to sense
battery temperature, and resistor R1 sets the charge
rate. With the trickle charger, RT1 turns on the charge
indicator, and R1 is not used.

Intrinsically Safe 1400 mAH Battery Pack, Part
Number 587-8565-162, is similar to the standard pack
except that it has a series resistor connected to the
negative terminal of the battery. This resistor limits
current if a short circuit occurs.

The battery pack is a sealed unit that is not
intended to be serviced. If the pack fails to hold a
charge or is defective for some other reason, it must be
replaced with a new unit. The batteries in this pack
have a nominal capacity of 1400 mAH. Typical oper­ating time before recharge is 13 hours. This time
assumes that the transceiver is in the standby mode
(receive, audio squelched) 90% of the time, the
receive mode (receive, rated audio out) 5% of the
time, and the transmit mode 5% of the time.

5.1.2 BATTERY CARE

With proper care, a battery pack should provide
many months of service. One major cause of short­ened battery life is repeated deep discharge. There­fore, recharging should occur soon after the trans­ceiver low battery indication appears. This indication
appears when the battery pack voltage drops to

Figure 5-1 Battery Schematic

approximately 1 volt per cell or 6 volts for these
packs. Do not continue operating the transceiver until
it is completely nonfunctional.

Another cause of shortened battery life is
frequent use at temperature extremes. Maximum
battery life is achieved if the ambient temperature
when using or recharging a battery is 68-

86° F (20-30°

C). The recommended temperature ranges for the
various battery functions are as follows:

Function Fahrenheit Celsius

Charging +50 to 104
Actual Use –4 to +140

° +10 to 40
° –20 to +60°

Storage –22 to +122° –30 to +50°

5-1

Revised February 1997

Part No. 001-8560-381

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

Table 5-1 Battery Charge Times

Charger Part No.

Rapid Chargers (∆T/∆t) 239-5800-400/-476 2

Rapid Chargers (standard) 239-5800-300/-376 3

Vehicle Adapter 239-5810-500 2

In-Line (100 mA) 563-0001-003 16

[1] Charge times shown are in hours and are for a pack discharged to the point at which the trans­ceiver low battery indication appears.

With the -300/-376 chargers, charging a battery
pack at the temperature extremes may cause over­charging if temperature is low or undercharging if
temperature is high. The reason for this is that these
chargers sense battery temperature to determine when
the pack is fully charged, and at the temperature
extremes, this temperature may not accurately indicate
the battery charge. With the new technology -400/-476
chargers, this is not a problem because rapid charging
does not occur if battery temperature is not in the
normal range.

Another cause of shortened battery life is regu­larly leaving fully charged battery packs in the charger
for extended periods. In addition, short circuiting a
battery pack may cause overheating which can also
reduce life.

Charge Time [1]

1400 mAH Pack

packs in the rapid and trickle chargers. The pack can
be installed in the charger backwards. When this
happens, the charge indicator does not turn on and no
charging occurs. The pack can be charged while
attached to the transceiver. However, charge time may
be slightly longer, especially with the trickle charger.
Typical charge times are shown in Figure 5-1.

NOTE: The E.F. Johnson Company recommends the
use of the new technology battery chargers described
in the next section. They result in more charge/
discharge cycles, longer operating time, faster
charging, and reduced heat generation than the other
chargers described in this section.

5.2.2 FIVE-UNIT AND SINGLE-UNIT RAPID CHARGERS (-400/476 MODELS)

It is possible that a battery pack could develop a
characteristic called “memory”, even though these
battery packs are designed to minimize this effect.
When a battery develops a memory, it reacts as though
it is totally discharged even though it has greater
capacity. The memory effect may be caused by consis­tently discharging a pack only slightly and then
recharging it, charging at too high a temperature, or
extended storage. If a pack develops this problem, it
can usually be corrected by performing three complete
discharge/charge cycles.

5.2 BATTERY CHARGERS

5.2.1 INTRODUCTION

Chargers currently available to charge this battery
pack are listed in Table 1-2. Charger Inserts, Part No.
032-0757-233, are required to charge the 857x/859x

Revised February 1997
Part No. 001-8560-381

The new technology -400/-476 rapid chargers use
state-of-the-art
in time) and -

∆Τ/∆t (change in temperature/ change

∆V (negative change in voltage) sensing

to determine when the battery is nearly fully charged.
This type of sensing prolongs battery pack life
because overcharging is minimized.

The -400 five-unit and -476 single-unit chargers
operate basically the same. Operation is in the fast
charge mode until the battery pack is approximately
95% charged. Charging is then in slow mode until the
pack is removed from the charger. The charge rate in
the fast mode is determined by resistor R1 in the
battery pack. With these battery packs, the fast rate is
approximately 1000 mA (1400 mAH pack) and the
slow rate is approximately 70 mA.

When the battery is inserted in the charger, the
charge indicator usually turns on continuously to indi-

5-2

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

cate that charging in the fast mode is occurring. If this
indicator flashes slowly when the pack is inserted, it
indicates that charging is occurring at the slow rate.
This occurs if the battery temperature is not in the
required range of +50 to +1

04° F (+10 to +40° C) or if

the battery voltage is below 6 volts. When these
parameters return to the normal range, the charger
automatically switches to the fast rate.

The primary method used by these chargers to
detect a fully charged battery is to sense the point at
which the battery temperature begins increasing at a
faster rate. This normally provides the first indication
that the battery is fully charged. If this method does
not indicate a charged battery, the charger also detects
a negative change in battery voltage (minus

∆V). This

also indicates a fully charged battery.

To provide fail-safe operation, the charger also
switches to the slow rate if the battery temperature
rises above approximately 113

° F or total charge time

in the fast mode exceeds approximately 3 hours.
(Sensing 113

° F results in operation similar to that of

the -300/-376 chargers described in the next section.)
When the battery is fully charged, the charge indicator
begins flashing rapidly and the slow rate is selected.
Flashing and the slow rate continue until the battery is
removed from the charger.

5.2.3 SIX-UNIT AND SINGLE-UNIT RAPID

CHARGERS (-300/376 MODELS)

The -300 six-unit charger and -376 single-unit
chargers have been replaced by the chargers discussed
in the preceding section. The six-unit and single-unit
models operate basically the same. Operation is in the
rapid charge mode until the battery pack is approxi­mately 80% charged. Charging is then in slow mode
until the battery pack is removed from the charger. The
charge rate in the rapid mode is determined by resistor
R1 in the battery pack. With these battery packs, the
rapid rate is approximately 850 mA (1400 mAH pack)
or 750 mA (1000 mAH pack) and the slow rate is
approximately 90 mA.

When the battery is inserted in the charger, the
red FAST indicator normally lights to indicate that
charging in the rapid mode is occurring. If this indi­cator does not light, the pack may be installed in the
charger backwards or the battery temperature may not

be in the required range of +50 to +1
+45

° C). When the temperature is not in this range,

13° F (+10 to

charging is at the slow rate.

When the battery temperature reaches approxi-

mately 113

° F, the battery is almost fully charged and

charging switches to the slow mode which is approxi­mately 90 mA. This mode is indicated when the green
SLOW indicator lights.

5.2.4 TRICKLE CHARGER

The trickle charger is a single-unit charger
designed to recharge the battery pack in about 16
hours as indicted in Figure 5-1. This charger consists
of base, Part No. 239-5800-371, and in-line charger,
Part No. 563-0001-003. The in-line charger plugs into
117 VAC power and provides 100 mA of charge
current at 7.5 VDC.

When the battery pack is inserted in the charger,
the red charge indicator should light. If it does not, the
battery pack may be in the charger backwards or it
may be fully discharged. If the pack is fully
discharged, it may need to charge for a short time for
the indicator to light. If it still does not light, try
partially charging it in a rapid charger.

NOTE: It is recommended that one of the rapid
chargers be used whenever possible. The battery packs
are optimized for rapid charging and will usually
provide more charge/discharge cycles when charged
in a rapid charger.

5.2.5 VEHICULAR ADAPTER

When the transceiver is plugged into the optional
vehicle adapter, the battery pack is charged by a
charger circuit in the system interface unit that oper­ates basically the same as the -300/-376 rapid chargers
described in the preceding section. Differences are that
the rapid charge rate is approximately 1.0 ampere, and
a powered-up transceiver is sensed by monitoring the
switched 7.5-volt supply. When a powered-up trans­ceiver is detected, the charger current increases by
approximately 65 mA. The FAST and SLOW indica­tors are located on the interface connector that is
plugged into the transceiver accessory connector. If
Vehicle Charger, Part No. 239- 5810-511, is used, a
trickle charge of approximately 80 mA is provided.

5-3

Revised February 1997

Part No. 001-8560-381

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

5.3 VEHICULAR ADAPTER

The optional Vehicle Adapter, Part No. 239-5810­500, is shown in Section 5-3. This accessory allows
this transceiver to be used as a mobile transceiver
(mounted in a vehicle). A handheld transceiver is
converted to mobile use by simply sliding it into a
special connector mounted in the vehicle. This
connects it to vehicle antenna and also to the system
interface unit. The system interface unit provides
battery charging and interconnection with such things
as a remote control unit and external speaker.

When the remote control unit is not used with this
adapter, the only transceiver function that can be
controlled remotely is transmitter keying which can be
performed by a handheld microphone. The micro­phone and push-to-talk switch of the transceiver can
also be used if desired. However, the backlight and
auxiliary switches on the side are not accessible.

An external speaker is always required because
the audio to the internal speaker automatically mutes
when the transceiver is plugged into the interface
connector. This speaker is driven by an amplifier in the
interface unit, and the volume level is controlled by
the transceiver volume control. Transceiver power
turns on and off with the vehicle ignition switch. Refer
to the Vehicle Adapter and Charger Service Manual,
Part No. 001-5810-501, for more information.

5.4 VEHICULAR CHARGER

Vehicular Charger, Part No. 239-5810-811,
provides a low-cost means of converting to vehicle
operation. This charger consists of a cable and small
junction box as shown in Section 5-2. The junction
box provides jacks for connecting vehicle power and
the vehicle antenna. It does not have jacks for
connecting a microphone, speaker-microphone, or
speaker. However, locations for these jacks are
provided on the junction box PC board and the end
panels have the required knockouts. The part numbers
of these jacks and a speaker-microphone for this appli­cation are as follows.

Description Part No.

Modular microphone jack 515-2006-040
Speaker-mic jacks (both req’d)

Miniature for speaker 515-2002-012

3.6 mm for microphone 515-2001-011
Speaker-microphone 589-0015-011
Speaker jack, 3.6 mm 515-2001-011

The difference between the -811 charger and the ­511 charger designed for the 5876 transceiver is that
the -811 does not have the magnets required by the

5876. These magnets switch the antenna and speaker
when the transceiver is plugged into the interface
connector. They are not required with the 85xx trans­ceivers because this switching is accomplished by
sensing a load on those outputs. The vehicular charger
provides an 80 mA trickle charge which is usually
adequate to maintain the charge of the battery. To
recharge a battery, one of the chargers described in
Section 5.2 should be used.

Figure 5-2 Vehicular Charger Components

Revised February 1997
Part No. 001-8560-381

5.5 ADAPTER INSTALLATION COMPONENTS

The components required for installation are
shown in Figure 5-3. The part numbers of the compo­nents identified by item number are shown in
Table 5-5. Vehicular Adapter Assembly, Part No. 239­5810-500, includes items 1-5 and also the required
mounting hardware such as screws and a microphone
hanger. The -545 hinge mount is used if the adapter
must be tilted from the mounting surface. The -550
interface connector has a female BNC connector for
interfacing with the vehicle antenna.

5-4

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

NOTE: To connect an antenna with a Type N
connector to the BNC connector on the cable, adapter,
Part No. 515-3102-015, is required.

When the remote control unit is used, the addi­tional accessories which may be required are listed in
Table 5-4. When the remote control unit is ordered
using the 250 number listed in Table 5-4, the junction
box and power cable which are not required are not
included. If one of the optional mounting brackets are
required, the standard mounting plate must still be
used.

Installation instructions (Part No. 004-5810-500)
are included with the Vehicular Adapter. These
instructions describe installation of the interface
connector, system interface unit, and control unit.
They also describe control unit programming.

5.6 ADAPTER TELEPHONE CALLING

If telephone calls are placed, a DTMF micro­phone can be used in place of, or in addition to, the
keypad on the transceiver. However, a DTMF micro­phone cannot be used to program numbers into
memory or enter numbers into the phone mode buffer.
When the remote control unit is used and the phone
mode has been selected by the P1 key, the P2 key can
be used to step through the eight phone numbers
stored in memory. This can be done even if the trans­ceiver does not have the telephone keypad (as long as
there are dealer-programmed telephone numbers).

5.7 REMOTE CONTROL UNIT

the Remote Control Unit Service Manual, Part No.
001-8610-502. The remote control unit cannot be used
with the -811 charger because the data lines are not
brought out to the box.

5.7.2 CONTROLS AND INDICATORS

The equivalent transceiver and control unit
switches are shown in Table 5-2. Likewise, the equiv­alent transceiver and control unit display characters
are shown in Table 5-3.

5.7.3 MISCELLANEOUS CONTROL UNIT

INFORMATION

Microphone Hanger - The microphone hanger
controls the monitor mode similar to the Monitor key
(off-hook = monitor). In addition, taking the micro­phone off-hook disables system and group scanning if
it is enabled.

Turning Power On and Off - Power to both the
transceiver and control unit is controlled by the
control unit PWR switch. However, the vehicle’s igni-
tion switch also normally controls power. Therefore, it
must be in the On or Accessory position for power to
turn on. When the ignition switch is turned off and
power has not been turned off by the PWR switch,
power remains on for the programmed delay period
(see next description). The control unit can also be
installed so that the ignition switch does not control
power. Power is then controlled only by the PWR
switch and a turn-off delay is not available. The trans­ceiver on-off/volume control is nonfunctional when
the control unit is used with the vehicular adapter.

5.7.1 INTRODUCTION

NOTE: Early remote control units cannot be used
because several hardware and software changes are
required for this application. These changes have been
incorporated into control units with a revision letter of
“C” or higher. These units were manufactured after
approximately October 1989.

The remote control unit shown in Figure 5-4 can
be used with the vehicular adapter (see Section 5.3).
The remote control unit enhances operation by making
the transceiver controls more accessible. Service
information for the remote control unit is located in

Turn-Off Delay - When the ignition switch controls
power as described in the preceding paragraph, there
is a turn-off delay that can be programmed (see
Section 4.2). This delay can be 0, 10, 20, or 30
minutes, 1, 2, or 4 hours, or an infinite time (no turn­off occurs). The delay period begins when the igni­tion switch is turned off with the control unit power
on. It can be canceled by turning power off using the
PWR switch or turning the ignition switch back on.
This delay can

be used to keep functions such as the

Call indicator, horn alert, and battery charger func­tional for a limited time after the vehicle is turned off.
It can also be used to prevent accidental discharge of
the vehicle battery.

Revised February 1997

5-5

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BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

Table 5-2 Equivalent Control Unit Switches

Function

Volume Control On-Off/Vol VOLUME

System Select S SYSTEM

Group Select G GROUP

Scan List Prog LCK LOCK

Phone Mode Select PHON P1

Return/RCL No. RTN P2

Monitor Auxiliary Sw MON/AUX

Horn Alert None HORN

Send Phone No. SEND CALL

Enable Volume Set
Tone

Push-To-Talk PTT Switch Mic PTT Sw

Transceiver

Switch

None SET

Control Unit

Switch

Mic Hanger

Horn Alert - When the remote control unit is used, a
horn alert feature is available to signal an incoming
call when the user is away from the vehicle. With LTR
systems, each of the two fixed priority ID codes and
the selectable ID codes can be programmed to enable
the horn alert. With conventional systems, each
channel can be programmed so that the horn alert is
activated when a call is received.

Table 5-3 Equivalent Control Unit Indicators

Function

Transmitter Keyed TX XMIT

Monitor Mode MON MON

Horn Alert Enable None HORN

Call Indicator CALL CALL

High Power Sel None HI

Low Power Sel None LO

Scan List Delete

Scan Mode Sel SCN SCAN

Phone Mode Sel PHONE P1

Telephone Group None

Busy Conv Chan BUSY BUSY

Key Press Tone
Mute

Overflow Digits None

Low Battery None

Transceiver

Indicator

▼ (LCK) ←LOCKOUT→

MUTE None

Control Unit

Indicator

When a call is received that activates the horn
alert, the horn alert turns on once per second for 3
seconds and then deactivates. The horn alert output is
on the system interface unit, and is active only when
the ignition switch is off with the control unit in its
turn-off delay. The horn alert is turned on and off by
the HORN button on the control unit. It is enabled
when “HORN” is displayed. More information is
located in the Vehicular Adapter and Charger Service
Manual, Part No. 001-5810-501.

Control Unit Display - The control unit displays the
same unique 7-character system or 5-character group
identification as the transceiver display. Other infor­mation displayed in that area of the transceiver display
is also indicated by the control unit display.

Table 5-4 Control Unit Accessories

Item

No.

10 Std Ctrl Unit Mounting Plate -

& hard (included w/item 9)

Control Unit Mounting Brackets

11 Floor Mount 023-1154-221

12 Hinge 023-1154-226

13 Swivel 023-1154-530

Junction Box Assembly 023-8610-520

Accessory Part No.

Revised February 1997
Part No. 001-8560-381

5-6

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

Figure 5-3 Vehicular Adapter Components

Table 5-5 Vehicle Adapter Accessories

Item

No.

Vehicle Adapter Accessory 239-5810-500

Includes:

1 Interface Connector 023-5810-550

2 System Interface Unit 023-5810-500

3 Power Cable 023-4144-410

4 Horn/Ignition Cable 023-5810-520

5 Mounting Bracket 017-2222-128

Accessory Part No.

5-7

Table 5-5 Vehicle Adapter Accessories

Item

No.

Other Optional Accessories:

Microphones:

6 Amplified Dynamic 250-0740-300

- DTMF 250-0751-021

7 Hinge Mount 023-5810-545

8 Speaker, 15W 3.2 ohm 250-0151-005

9 Remote Control Unit 250-8610-506

14 BNC-N adapter 515-3102-015

Accessory Part No.

Revised February 1997

Part No. 001-8560-381

BATTERY & VEHICULAR ADAPTER/CHARGER INFORMATION

5.7.4 SENDING STATUS INFORMATION

When the remote control unit is used, status
information can be transmitted to a dispatcher when a
Multi-Net system is selected. This feature is available
if the STATUS key has been enabled by control unit
programming and status messages have been
programmed into the control unit. One of up to eight
status conditions can then be selected using the
STATUS key. The number representing the currently

POWER SWITCH
SYSTEM/GROUP IDENTIFICATION
SYSTEM NUMBER
GROUP NUMBER
VOLUME LEVEL
VOLUME UP/DOWN SWITCHES
SYSTEM UP/DOWN SWITCHES
GROUP UP/DOWN SWITCHES

selected status condition is transmitted whenever the
transmitter is keyed.

To momentarily display the currently selected
status, press the STATUS key once. To change the
status, press this key again while this information is
displayed. This cycles through the available choices.
For example, status conditions such as AT SITE, LVG
SITE, or UNLOADING can be displayed. This infor­mation is not displayed by the transceiver display.

Revised February 1997
Part No. 001-8560-381

Figure 5-4 Remote Control Unit

5-8

SECTION 6 CIRCUIT DESCRIPTION

CIRCUIT DESCRIPTION

6.1 6.1 GENERAL

6.1.1 INTRODUCTION

This transceiver has ten separate modules and a
logic board which connect to a mother board. All these
assemblies can be plugged into the mother board
except for the TCXO and power amplifier modules
which must be unsoldered. Three flexible circuits
provide interconnection between the mother board and
the top-panel controls and connector, side-panel
controls, and battery terminals. The information which
follows provides a general description of each of these
sections. Later sections then provide a detailed
description.

The logic board is mounted on the inside of the
front cover and unplugs from the mother board when
the front cover is removed. Therefore, the extension
test cable in Table 1-2 is required to operate the trans­ceiver with the front cover removed. Removing the
back cover exposes the bottom of the mother board.
Most troubleshooting is done from the bottom of the
mother board because module components are gener­ally not accessible with the modules installed.

All circuitry of the transceiver is protected
against short circuits by a 2-ampere fuse on the bottom
of the mother board. This fuse is F201 and it is located
near the battery end of the board.

In the circuit description which follows and also
the schematic diagrams, the various modules have
been grouped into synthesizer, receiver, transmitter,
and audio/logic sections. The modules which make up
each section are as follows:

Section Modules

Synthesizer VCO

Synthesizer
Doubler/Filter
TCXO

Receiver RF Amplifier/Mixer

IF

Transmitter Transmitter

Filter/Antenna Switch
Transmit Audio/Power Ctrl [1]

Audio/Logic Logic Board

Data Filter/Receive Audio
Transmit Audio/Power Ctrl [1]

[1] The power control section of this module is on the

transmitter schematic and the transmit audio section is
on the audio/logic schematic.

6.1.2 SYNTHESIZER

The synthesizer output signal is produced by a
VCO (Voltage-Controlled Oscillator) on the VCO
module. This signal is then fed to doubler/filter
module, doubled, and then fed to the receiver as the
first injection signal and the transmitter as the transmit
signal.

Channels are selected by programming the
counters in synthesizer chip U351 on the synthesizer
module to divide by a different number for each
channel. This programming data comes from the
microcomputer on the logic board. The frequency
stability of the synthesizer in both the receive and
transmit modes is determined by the stability of
TCXO Y610. The stability of Y610 is 2.5 PPM from –
22 to +140 degrees F (–30 to +60 degrees C).

6.1.3 RECEIVER

The receiver is a double-conversion type with
intermediate frequencies of 44.9625 MHz and 450
kHz. Receiver selectivity is enhanced by a four-pole

44.9625 MHz crystal filter. Two three-pole bandpass
filters in the front end attenuate the image, half IF,
injection, and other frequencies which could degrade
receiver performance.

The first injection frequency of 44.9625 MHz is
slightly offset from 45 MHz so that the injection
frequency is not the same as the transmit frequency
(the mobile transmit channels are 45 MHz below the
receive channels). This minimizes desensitization of
nearby repeaters caused by slight radiation of the
injection signal.

6-1

Revised February 1997

Part No. 001-8560-381

CIRCUIT DESCRIPTION

Revised February 1997
Part No. 001-8560-381

Figure 6-1 Transceiver Block Diagram

6-2

CIRCUIT DESCRIPTION

6.1.4 TRANSMITTER

The transmitter module amplifies the synthe­sizer signal to produce a power output of 1 watt. All
audio and data modulation occurs in the synthesizer. A
power control circuit on the transmit audio/power
control module maintains a constant power output by
sensing current to the transmitter module.

6.1.5 AUDIO/LOGIC SECTION

Microcomputer-based control logic on the logic
board provides synthesizer programming, system scan,
Multi-Net data encoding and decoding, and other
functions. Channel information and other operating
parameters are stored by EEPROM U804 (refer to
Section 4.1.5 for more information). The audio ampli­fier is also located on the logic board.

Data and receive audio filtering and transmit
audio processing are also part of the audio/logic
section. The data filtering circuitry located on the data
filter/receive audio module provides filtering of the
receive and transmit data and Call Guard signals. The
receive audio circuitry on this module attenuates
frequencies below 300 Hz and above 3 kHz. The
transmit audio processing circuitry located on the
transmit audio/power control module provides
processing of the transmit audio/data signal that is fed
to the synthesizer.

The reference input to the phase detector (fR) is
the 14.8375 MHz TCXO frequency divided by the
reference counter in U351. The reference frequency is

6.25 kHz for all channels. Refer to Section 6.2.8 for
more information.

The input from the VCO (fV) is divided down by
prescaler U352 and the N counter in U351. These
counters are programmed for each channel to produce
an input to the phase detector which is the same as the
reference frequency (fR) when the VCO is oscillating
at the correct frequency. The prescaler divide number
is controlled by the A counter in synthesizer U351.
The three counters in U351 are programmed by micro­computer U801 on the logic board.

6.2.2 VOLTAGE-CONTROLLED OSCILLATOR

Oscillator (Q301!

The voltage-controlled oscillator (VCO) is
formed by Q301, several capacitors and varactor
diodes, and a section of microstrip*. It oscillates at
half the transmit frequency in the transmit mode and
half the first injection frequency in the receive mode
(about 400 MHz). Biasing of Q301 is provided by
R305, R306, and R309. RF choke L305 blocks the
flow of RF through R309, and R308 provides isolation
between the tank circuit and Q301. An AC voltage
divider formed by C313, C314, C315, and C316
initiates and maintains oscillation and also matches
Q301 to the tank circuit.

6.2 SYNTHESIZER CIRCUIT DESCRIPTION

6.2.1 INTRODUCTION

A block diagram of the synthesizer is shown in
Figure 6-1. The synthesizer output signal is produced
by a voltage-controlled oscillator (VCO) on the VCO
module. The VCO frequency is controlled by a DC
voltage produced by the phase detector in synthesizer
chip U351. This phase detector senses the phase and
frequency of the two input signals. One signal is a
reference frequency from the TCXO (fR) and the other
signal is from the VCO (fV). If these signals are not
the same frequency, the phase detector changes the
VCO control voltage which changes the VCO
frequency until both input signals are synchronized.
The VCO is then said to be locked on frequency.

The microstrip is grounded at one end and
provides distributed series inductance and shunt
capacitance to the tank circuit. C310 and a tuning stub
of the microstrip are used to tune the tank circuit to the
desired frequency range. The tuning stub is laser
trimmed at the factory.

*

Microstrip is a form of transmission line with series inductance

and shunt capacitance. The characteristic impedance is determined

by the width of the line and the PC board material and thickness.

Frequency Control and Modulation

The VCO frequency is controlled by the DC
voltage across varactor diode CR304. As the voltage
across a reverse-biased varactor diode increases, its
capacitance decreases. The result is that the VCO

Revised February 1997

6-3

Part No. 001-8560-381

CIRCUIT DESCRIPTION

frequency increases as the control voltage increases
and vice versa. The VCO control line is isolated from
tank circuit RF by choke L304 and bypass capacitor
C312. The amount of frequency change produced by
CR304 is controlled by C311 which is in series with
CR304.

The VCO frequency is modulated in a similar
manner. The transmit audio/data signal is applied
across varactor diode CR303. This varies the VCO
frequency at an audio rate. C307 and C308 in series
with CR303 set the amount of deviation produced by
the modulation signal. L303 provides a DC ground on
the anode of CR303. Resistors R303 and R304 provide
summing of the 5-volt bias and the modulation signal.
C225 on the mother board provides DC blocking so
that changes in the transmit audio circuit bias supply
do not affect the TCXO frequency. Potentiometer
R201 on the mother board balances the VCO and
TCXO modulation signals. Refer to Section 6.2.3 for
more information.

C309 provides compensation so that modulation
remains flat over the entire bandwidth of the VCO.
This compensation is required because modulation
tends to increase as the capacitance of CR304 gets
lower (VCO frequency gets higher).

Talk-Around Mode Frequency Shift

A circuit formed by PIN diode CR301 and
several inductors and capacitors is used to increase the
operating band of the VCO when transmitting in the
talk-around mode. In this mode, transmission is on the
receive frequency to permit mobile-to-mobile commu­nication. The VCO frequency must therefore increase
half the 45 MHz transmit/receive spacing or 22.5 MHz
(the VCO frequency is later doubled). If this large of a
shift was achieved by increasing the control voltage,
the required VCO gain would be undesirably large.
Therefore, the VCO frequency is increased by
switching additional inductance into the tank circuit.
This inductance is provided by a section of microstrip
on each side of CR301. This microstrip switched into
the circuit as follows:

Programming data for synthesizer chip U351 is
shifted through U353 which is an eight-stage shift
register. The output of the last stage (QS) programs
U351, and the Q3 and Q4 outputs control VCO
frequency shifting. After U351 is programmed, bits

remain in the Q3 and Q4 stages. In the talk-around
mode, the Q3 output is high and the Q4 output is low
which forward biases PIN diode CR301. When a PIN
diode is forward biased, it has a very low impedance.
Therefore, C301, the two sections of microstrip, and
C302 are effectively part of the tank circuit which
increases the frequency by approximately 22.5 MHz.
In the normal (not talk-around) mode, the Q3 and Q4
outputs of U353 are the opposite states, so CR301 is
reverse biased. It then presents a high impedance and
the two sections of microstrip are effectively switched
out of the tank circuit. C301/C302 provide DC
blocking, L301 is an RF choke, and R301 provides
current limiting.

6.2.3 VCO AND TCXO FREQUENCY MODULATION

Both the VCO and TCXO are modulated in order
to achieve the required frequency response. If only the
VCO was modulated, the phase detector in U351
would sense the frequency change and increase or
decrease the VCO control voltage to counteract the
change (especially at the lower audio frequencies). If
only the TCXO frequency was modulated, the VCO
frequency would not change fast enough (especially at
the higher audio frequencies). However, by modu­lating both the VCO and TCXO, the two phase
detector inputs remain in phase and no frequency shift
is sensed. This produces a flat audio response. Potenti­ometer R201 on the mother board balances the modu­lating signals.

6.2.4 ACTIVE FILTER (Q305)

Q305 functions as a capacitance multiplier to
provide filtering of the 5.7-volt supply to Q301. R318
provides transistor bias, and C328 provides the capaci­tance that is multiplied. If a noise pulse or other
voltage change appears on the collector, the base
voltage does not change significantly because of
C328. Therefore, the base current does not change and
transistor current remains constant. CR305 decreases
the charge time of C328 to shorten the start-up time of
the oscillator when power is turned on. R307 provides
isolation, and C322 is an RF bypass capacitor.

6.2.5 BUFFER (Q303, Q304)

A cascode amplifier formed by Q303 and Q304
provides amplification and also isolation between the

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Part No. 001-8560-381

6-4

CIRCUIT DESCRIPTION

VCO and doubler/filter module. A cascode amplifier
is used because it provides high gain and consumes
only a small amount of power. The input signal to this
amplifier is tapped from the collector of VCO Q301.
Capacitor C320 provides DC blocking and L307
provides impedance matching. Bias for the amplifier is
provided by R314-R317. RF bypass is provided by
C329, C323, C324, and C326. The output of Q303/
Q304 is matched to the doubler/filter module by L308
and C327. Resistor R313 is used to lower the Q of
L308 to broaden its response.

6.2.6 PRESCALER BUFFER (Q302), PRESCALER (U352)

Q302 provides amplification and isolation
similar to Q303/Q304. The input signal is tapped from
the emitter of VCO Q301 with C317 providing
matching and DC blocking. R311 and R312 provide
biasing, R310 provides supply voltage isolation, and
C318 is an RF bypass capacitor. Impedance matching
with prescaler U352 is provided by L306 and C319.

U352 is a dual-modulus prescaler. A prescaler is
a digital counter capable of operating at high frequen­cies, and dual modulus refers to the two divide
numbers, 128 and 129. This counter divides an input
signal in the 400 MHz range down to the 3 MHz range
so that it is within the operating range of the counters
in synthesizer U351. Since the prescaler utilizes
emitter-coupled logic (ECL), the logic swing is rela­tively small and the device may feel warm to the
touch. The prescaler divides by 128 when the control
signal from U351 on pin 6 is high, and by 129 when it
is low.

6.2.7 DOUBLER/FILTER (Q431, Q432, Q433)

and transmitter. C441, R440, and C437 provide
impedance matching between the filter and Q432.
Impedance matching on the output of Q432 is
provided by a section of microstrip and C439.

The same bias current is shared by Q431 and
0432 in order to conserve power. This bias current is
controlled by Q433 which functions as a constant
current source. Q433 provides base bias current to
Q432 which in turn provides collector-emitter current
for Q431. Current flows through Q431 and Q432 so
that the voltage across R433 is equal the voltage
across R431 (minus the base-emitter drop of Q433).
Several 0.01 µF and 100 pF capacitors in the circuit
bypass RF frequencies.

6.2.8 SYNTHESIZER INTEGRATED CIRCUIT

(U351)

Introduction

A block diagram of synthesizer chip U351 is
located in Figure 6-2. This device contains the
following circuits: R (reference), N, and A counters;
phase and lock detectors; and counter programming
circuitry. The basic operation of U351 was described
in Section 6.2.1.

Channel Programming

Channels are selected by programming the R, N,
and A counters in U351 to divide by a certain number.
These counters are programmed by microcomputer
U801 on the logic board. The counter programming
numbers are stored in EEPROM U804 when the trans­ceiver is programmed. These counters are
programmed as follows:

The VCO signal from buffer Q303/Q304 is
applied to doubler Q431 on the doubler/filter module.
Impedance matching between these stages is provided
by R442, R435, C434, and L431. The output signal
from Q431 is applied to a bandpass filter formed by
microstrip. This filter attenuates the VCO frequency
and other unwanted signals above and below approxi­mately 800 MHz. Impedance matching with the filter
is provided at twice the VCO frequency by a section of
microstrip, C436, and R439.

From the filter the signal is fed to buffer Q432
which provides isolation and also drive to the receiver

Data to be loaded into U351 is clocked through
shift register U353. It is applied to the DATA input
(pin 10) of U351 and clocked in a bit at a time by a
low to high transition on the CLOCK input (pin 11).
Data is first loaded into the 1-bit register (refer to
Figure 6-2), and then into the 7-, 1O-J and 14-bit
registers. The last bit loaded is present in the 1-bit
register and it determines which counters will be
programmed. If this bit is a 1, the data is latched into
all three counters when the latch ENABLE input (pin

11) goes high. If this bit is a 0, data is latched into only
the A and N counters.

Revised February 1997

6-5

Part No. 001-8560-381

CIRCUIT DESCRIPTION

U351 Operation

As previously stated in Section 6.2.1, the counter
divide numbers are chosen so that when the VCO is
operating on the correct frequency, the VCO-derived
input to the phase detector (fV) is the same frequency
as the TCXO-derived input (fR).

The fR input is produced by dividing the 14.8375
MHz TCXO frequency by 2374. This produces a
reference frequency (fR) of 6.25 kHz. Since the VCO
frequency is later doubled, this frequency allows chan­nels to be changed in 12.5 kHz steps if required. The
reference frequency is 6.25 kHz for all channels
selected by this transceiver.

The fV input is produced by dividing the VCO
frequency using prescaler U352 and the N counter in
U351. As stated in Section 6.2.6, the prescaler divides
by 128 or 129. The divide number of the prescaler is
controlled by the N and A counters in U351. The N
and A counters function as follows:

Both the N and A counters begin counting down
from the number that they are programmed with.
When the A counter reaches zero, it halts until the N
counter reaches zero. Both counters then reset and the
cycle repeats. The A counter is always programmed
with a smaller number than the N counter. While the A
counter is counting down, the modulus control output
to the prescaler on pin 12 is low and the prescaler
divides by 129. Then when the A counter is halted, the
modulus control output is high and the prescaler
divides by 128.

To illustrate the operation of these counters, an
example will be used. Assume a transmit frequency of

818.5125 MHz (Channel 500). Since the VCO
frequency is half this frequency, it must be 409.25625
for this channel. To produce this frequency, the N and
A counters are programmed as follows:

N = 511 A = 73

56,064 + 9417 or 65,481. The VCO frequency of

409.25625 MHz divided by 65,481 equals 6.25 kHz
which is the fR input to the phase detector. The overall
divide number K can also be determined by the
following formula: K= 128N + A Where, N = N
counter divide number and A = A counter divide
number.

NOTE: Section 7.5.6 describes how the N and A
counter numbers can be calculated for other channels.

6.2.9 LOCK DETECT (Q357)

When the synthesizer is locked on frequency, the
LOCK DETECT output on pin 7 of U351 is basically
a high voltage because only narrow negative-going
pulses are present. Then when the synthesizer is
unlocked, the negative-going pulses become much
wider.

When the synthesizer is locked, the 5-volt level
filtered by R361 and C363 turns Darlington amplifier
Q357 on and a logic 0 is applied to the PA3 input of
microcomputer U801 on the logic board. When the
synthesizer is unlocked, the negative-going pulses
widen and discharge C363 and C364 through CR354
and R362. The base voltage of Q357 drops below its
turn-on point and a logic 1 (5 volts) is applied through
R363 to the PA3 input of the microcomputer. When
the microcomputer detects an out-of-lock synthesizer,
“SYN ERR” is displayed and the audio is muted in the
receive mode or the transmitter is disabled in the
transmit mode.

6.2.10 VOLTAGE MULTIPLIER (Q355, Q356)

The voltage multiplier circuit provides the 12­volt DC supply to the charge pump circuit. The output
signal on pin 14 of U351 is the buffered 14.8375 MHz
TCXO signal. Q355 and Q356 are in a push-pull
configuration, so one stage is turning off while the
other is turning on. The output voltage on the emitter
is approximately 4.7 volts P-P.

To determine the overall divide number of the
prescaler and N counter, the number of VCO output
pulses required to produce an N counter output pulse
can be counted. In this example, the prescaler divides
by 129 for 129 x 73 or 9417 input pulses. It then
divides by 128 for 128 x (511-73) or 56,064 input
pulses. The overall divide number K is therefore

Revised February 1997
Part No. 001-8560-381

C356, C357, and C358 and several diodes form a
three-stage voltage adder circuit. CR351A initially
charges C358 to approximately 4.3 volts (assuming a
drop of 0.7 volt across the diode). The voltage across
C359 is then approximately 8.3 volts DC after the 4.7­volt P-P signal is added and the CR351B drop

6-6

CIRCUIT DESCRIPTION

Figure 6-2 Synthesizer U351 Block Diagram

subtracted. This charges C357 to approximately 7.6
volts DC and process repeats across C360 and C361/
C362 to produce an output voltage of approximately
15 volts. That voltage is limited to approximately 12
volts by zener diodes CR355 and CR356.

6.2.11 CHARGE PUMP (Q351-Q354), LOOP FILTER (C353, C354)

The charge pump circuit charges and discharges
C353, C354, and C355 in the loop filter to produce the
VCO control voltage. Pulses which control the charge
pump are fed out of U351 on pins 15 and 16. When
both phase detector inputs are in phase, these output
signals are high except for a very short period when
both pulse low in phase. If the frequency of the fR
input to the phase detector is higher than that of the fV
input (or if the phase of fR leads fV), the VCO
frequency is too low. The negative-going pulses on the
UP output (pin 16) then become much wider and the
DOWN output (pin 15) stays essentially high. If the
frequency of the fV input is greater than fR (VCO
frequency too high), the opposite occurs.

Q351 and Q352 are level translators which make
the 5-volt levels of U351 compatible with the 12-volt
supply to Q353 and Q354. Capacitors C351 and C352
momentarily bypass R351 and R355 when negative­going pulses occur. This speeds up the turn-off time of
Q351 and Q352 by minimizing the effect of the base
charge.

When a negative-going pulse occurs on pin 16,
Q351 turns on which turns on Q353. The loop filter
capacitors then charge through Q353 and R354 which
increases the VCO control voltage. When a negative­going pulse occurs on pin 15, Q352 turns on which
turns on Q354 and the loop filter capacitors discharge
through Q354 and R358.

The loop filter formed by R359, R360, C353,
C354, and C355 provides low-pass filtering of the
signal from the charge pump. This filtering controls
synthesizer stability and lock-up time and suppresses
the 6.25 kHz reference frequency.

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CIRCUIT DESCRIPTION

6.3 RECEIVER CIRCUIT DESCRIPTION

6.3.1 CERAMIC FILTER (Z200, RF AMPLIFIER (Q501)

The receive signal from the antenna is fed
through the low-pass filter and antenna switch circuit
in the transmitter to bandpass filter Z201 on the
mother board. This is a three-pole dielectric filter with
a center frequency of 860.5 MHz, a bandwidth of 19
MHz, and an insertion loss of approximately 1.5 dB.
This filter attenuates the image and other unwanted
frequencies and also prevents the injection signal from
being fed back to the antenna.

The signal is then fed to RF amplifier Q501.
Impedance matching between the filter and Q501 is
provided by a section of microstrip* and C510. RF
amplifier Q501 provides approximately 9 dB of gain
to recover filter losses and increase the sensitivity of
the receiver. CR501 limits the negative-going peaks of
high-level input signals to prevent damage to Q501.

Q503 is a switched constant current source which
provides a base bias for Q501 that sets the collector
current of Q501 to 3 mA. In the receive mode, pin 8 is
0 volts and CR503A is reverse biased. Q503 base bias
is then provided by R501 and R504. Current flows
through R508 so that the voltage across it equals the
voltage across R504 (minus the base-emitter drop of
Q503). In the transmit mode, pin 8 goes to 7.5 volts
which forward biases CR503A and turns Q503 off.
This removes the bias from Q501 which disables that
stage in the transmit mode. This prevents noise and RF
from being amplified by Q501 and fed back on the
first injection line (particularly in the talk-around
mode when the transmit and receive frequencies are
the same). CR503A isolates the transmit 7.5-volt
supply from the 5-volt supply applied through R504.

The output from the RF amplifier is fed to band­pass filter Z202. This filter is the same as Z201 and
provides additional filtering. Impedance matching
with Q501 is provided by a section of microstrip and
C506. RF is bypassed by C511 and C501.

* Microstrip is a form of transmission line with series inductance
and shunt capacitance. The characteristic impedance is deter­mined by the width of the line and the PC board material and
thickness.

6.3.2 FIRST MIXER (Q502), CRYSTAL FILTER (Z521)

First mixer Q502 mixes the receive frequency

with the first injection frequency to produce the

44.9625 MHz first IF. Since low-side injection is used,

the injection frequency is 44.9625 MHz below the
receive frequency. Q502 and Q504 are similar in
design to Q501 and Q503 except that the collector
current of Q502 is set for 2 mA. Buffering and attenu­ation of the injection signal are provided by C509,
C511, R511, R513, and C512.

CR502, R510, and C508 are part of a network
which controls the routing of the synthesizer signal. In
the transmit mode, 7.5 volts is applied through R227
and CR207 on the mother board to pin 10. Current
then flows through PIN diode CR502 and R510. When
a PIN diode is forward biased, it presents a very low
impedance. Therefore, C508 effectively grounds the
quarter-wave line which exists between CR207 on the
mother board and pin 10. When one end of a quarter­wave line is grounded, the other end presents a high
impedance to the quarter-wave (transmit) frequency.
This effectively blocks the synthesizer signal from the
receiver in the transmit mode. In the receive mode, the
input to R227 is 0 volts, so both CR207 and CR502
are reverse biased. When a PIN diode is reverse
biased, it presents a high impedance (low capacitance).
Therefore, the synthesizer signal is blocked from the
transmitter and applied to the first mixer because the
quarter-wave line is no longer grounded by C508.

Several components on the output of Q502
provide impedance matching with the crystal filter.
They include L501, C507, C505, C525, L524, and
C524. Resistor R503 lowers the Q of L501 to make it
less frequency selective. C502, C503, and C504 are
RF bypass capacitors. The output impedance of pin 14
of the RF amp/mixer module is 50 ohms as is the input
impedance of pin 8 of the IF module.

Z521 is a four-pole crystal filter with a center
frequency of 44.9625 MHz and a –3 dB passband of
+7.5 kHz. This filter attenuates wideband noise, adja­cent channels, frequencies resulting from intermodula­tion, and other frequencies close to the receive
channel. The filter sections are a matched pair, and a
dot on the case of each section indicates which leads
connect together. Impedance matching on the output is

Revised February 1997
Part No. 001-8560-381

6-8

provided by C539, C523, L525, and C522. Variable
inductors L524 and L525 allow the networks to be
tuned for the best match.

6.3.3 SECOND MIXER/DETECTOR (U521)

U521 contains second mixer and oscillator,

limiter, detector, and squelch stages (refer to Figure 6-

3). The 44.9625 MHz first IF signal is fed into U521
on pin 1 which is the input of the internal mixer stage.
This signal is mixed with the 44.5125 MHz signal
from an internal oscillator to produce a second IF of
450 kHz.

The internal oscillator which produces the

44.5125 MHz injection signal uses LC network L523/
C534 to provide coarse frequency adjustment. An
internal varicap diode is then used to provide fine
frequency adjustment similar to the VCO described in
Section 6.2.2. The DC voltage across this diode is
adjusted by potentiometer R522. C541 provides RF
decoupling. The third harmonic of the TCXO
frequency is then used to lock the oscillator on

44.5125 MHz. Applying a signal near the operating
frequency of the oscillator tends to pull it to that
frequency. C535, C536, L522, and C540 form a band­pass filter tuned to the third harmonic, C537 is a
coupling capacitor, and R529 and R535 provide buff­ering.

The 450 kHz second IF is then fed out to ceramic
filter Z522. This filter has a center frequency of 450
kHz and a bandwidth of 15 kHz, and it is used to atten­uate wideband noise. The 450 kHz signal is then
applied to limiter stage in U521. The limiter amplifies
the 450 MHz signal and then limits it to a specific
value. This clips off part of the noise present in the
signal.

From the limiter the signal is fed to the quadra­ture detector. An external phase-shift network
connected to pin 12 shifts the phase of one of the
detector inputs 90 degrees at 450 kHz (the other inputs
are unshifted in phase). When modulation occurs, the
frequency of the IF signal changes at an audio rate as
does the phase of the shifted signal. The detector,
which has no output with a 90 degree phase shift,
converts the phase shift into an audio signal. Z523 is
adjusted to provide maximum undistorted output from
the detector. The audio signal is then fed out of U521
on pin 13.

CIRCUIT DESCRIPTION

Figure 6-3 Mixer/Detector U521 Block

Diagram

Pin 10 is an output from an internal RSSI (receive
signal strength indicator) circuit which provides
squelch control. Refer to the next section for more
information. C529 and several 0.047 and 0.01 µF
capacitors are used to decouple the 450 kHz and other
RF signals. R533 drops the supply voltage to U521 to
approximately 2.5 volts which also reduces current.

6.3.4 AUDIO/DATA AMPLIFIER (U522B),

SQUELCH COMPARATOR (U522A)

U522B amplifies the detected audio and data
signal and also shifts the DC bias level to 2.25 volts.
R531 and R537 set the gain at approximately three,
and R536 and R530 provide a DC reference level.
C538 bypasses the 450 kHz IF signal and C533
bypasses other frequencies. The output signal is then
fed to the data filter module which is described in
Section 6.6.2.

The output signal on pin 10 of U521 is a current
that is proportional to the strength of the 450 kHz IF
signal. When this signal reaches a preset level, the
output of comparator U522A goes high. The reference
voltage on pin 3 of U522A is provided by R534,
RT535, R526, R527, and R528. Thermistor RT535
provides temperature compensation of the reference
level, and R528 provides hysteresis to prevent an
intermittent squelch indication when receiving a weak
or fading signal. A voltage divider formed by potenti­ometer R521 and R523 sets the input level. Adjusting
R521 sets the squelch threshold, and C528 decouples
RF. This circuit operates as follows: When the signal

6-9

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Part No. 001-8560-381

CIRCUIT DESCRIPTION

strength increases, more current flows through R521
and R523, so the input voltage on pin 2 of U552A
decreases. When it drops below the reference on pin 3,
the output on pin 1 goes high and carrier detect is indi­cated to the logic. The reference voltage on pin 3 then
increases, providing hysteresis, so the input voltage on
pin 2 must increase by that amount for the output to go
back low and indicate loss of carrier.

6.4 TRANSM1TTER CIRCUIT DESCRIPTION

6.4.1 TRANSMITTER MODULE (U400)

The input to the transmitter module U400 is the
modulated transmit frequency from the doubler/filter
module shown on the synthesizer schematic. Trans­mitter module U400 amplifies the 1 milliwatt input
signal to approximately 1 watt. The gain of the module
is controlled by the DC voltage from the power control
circuit applied to a PIN diode attenuator consisting of
CR207 and CR502.

Pins 2, 3, and 4 are the supply voltage inputs to
the four amplifier stages in the module. The supply
voltage on pin 2 is the transmit switched 7.5-volt
supply, and the supply voltage to the last two stages
(pins 3 and 4) is the unswitched 7.5-volt supply direct
from the battery (through fuse F201). This supply
flows through resistors R207 and R217 on the mother
board. The voltage drop across these resistors is used
for power control as described in Section 6.4.5.

the RF line (pin 9) and ground. This resistance causes
Q451 to turn on because base current flows through
L455 and R456. The line between L455 and the
connector is a half-wave long. Therefore, when no
external antenna is connected, the line appears as an
open circuit where it connects to L455.

When Q451 is turned on, PIN diode CR454 is
forward biased by current flowing through R455 and
L454. Since a forward biased PIN diode presents a low
impedance, the discrete quarter-wave line formed by
C463 and L455 is effectively AC grounded at one end.
When one end of a quarter-wave line is grounded, the
other end presents a high impedance to the quarter­wave frequency. Therefore, the transceiver antenna is
effectively disabled when the transceiver is plugged
into the vehicle adapter. Capacitor C456 tunes out the
series inductance of CR454 when the diode is forward
biased, and C459 bypasses RF.

When the transceiver is not plugged into the
vehicle adapter, Q451 is turned off by R457. PIN
diode CR454 is then reverse biased and presents a
high impedance. Therefore, the quarter-wave line i no
longer grounded, so it provides a low-impedance path
to and from the transceiver antenna for the transmit
and receive signals. C457 provides DC blocking and
R454 dissipates static build-up on the antenna.

6.4.4 TRANSMIT/RECEIVE ANTENNA SWITCH

(CR452, CR453)

6.4.2 HARMONIC FILTER

The output from U400 is coupled by C452 and
CR451 to a harmonic filter formed by microstrip
printed on the ceramic substrate of the module. This is
a low-pass filter which attenuates frequencies occur­ring above the transmit band. The output of this filter
is fed to either the transceiver antenna or a mobile
antenna connected to the accessory connector.

6.4.3 EXTERNAL/INTERNAL ANTENNA

SWITCH (CR454, Q451)

The antenna switch formed by CR454, Q451, and
several other components controls which antenna is
used. When the transceiver is plugged into the optional
vehicle adapter interface connector, a resistance in the
connector of approximately 1k ohms is applied across

Revised February 1997
Part No. 001-8560-381

An antenna switch formed by PIN diodes CR451­CR453 and several other components switches the
antenna to the receiver in the receive mode and the
transmitter in the transmit mode. In the transmit mode,

7.5 volts is applied to pin 2 of the module through
L201 on the mother board. Current then flows through
CR451, L452, CR452, R451, L453, CR453, and R452.
Since a forward 1S biased PIN diode presents a low
impedance to the RF signal, the transmit signal is fed
through CR451 to the harmonic filter and antenna.

A discrete quarter-wave line formed by C461,
L452, and C462 is AC grounded at one end by CR452
and CR453 similar to the way the line described in the
preceding section was grounded by CR454. Therefore,
the transmit signal is blocked from the receiver. Two
PIN diodes are used to provide the required isolation.
C453 and C454 tune out the series inductance of

6-10

CIRCUIT DESCRIPTION

CR452 and CR453, respectively, when the diode is
forward biased. R451 and R452 provide current
limiting.

In the receive mode, the input to L201 is 0 volts,
so none of the PIN diodes are forward biased. Since an
“off” PIN diode presents a high impedance, the
receive signal is not fed through CR451 to the trans­mitter. The quarter-wave line is also no longer
grounded, so it provides a low impedance path into the
receiver. L451 tunes out the capacitance of CR451
when it is “off” which increases transmitter isolation.
C451 provides DC blocking.

6.4.5 POWER CONTROL (U601A)

The power control circuit maintains constant
power output by sensing the current to the last ampli­fier stages in transmitter module U400. This is done by
sensing the voltage drop across R207 and R217 on the
mother board. The voltage across those resistors is
applied to pin 5 of amplifier U601A. That stage ampli­fies the difference between that voltage and the refer­ence voltage on pin 6. The reference voltage is
produced by zener diode CR601, potentiometer R601,
and R602 and R603.

6.5 LOGIC BOARD DESCRIPTION

6.5.1 MICROCOMPUTER (U801)

Introduction

The digital control logic is based on a
68HC05C9 eight-bit CMOS microcomputer. This
particular device contains a 7744 byte ROM, 176 byte
RAM, 24 input/output lines, and two serial ports. The
operating speed of the microcomputer is set by crystal
Y801. The 4 MHz frequency of the crystal is divided
in half by an internal divider to produce an internal
operating frequency of 2 MHz.

Program Memory

The ROM (Read-Only Memory) in U801 is part
of the microcomputer chip and is mask programmed
when the device is manufactured. This memory
contains the operating program of the transceiver.
Other information which changes from transceiver to
transceiver, such as channels and operating features, is
stored in EEPROM U804.

Reset

The potentiometer effectively sets the power
output level when it sets the reference voltage. R608
and R609 on the output of U601A set the input level to
the transmitter module, and CR602 limits this input
level to 3.9 volts. Gates U602B and U602C prevent
current flow through U601 when power is off (U601 is
powered by the unswitched 7.5-volt supply).

The power control circuit operates as follows: If
the output power attempts to increase, current to the
transmitter module increases. The voltage drop across
R207 and R217 increases which causes the input
voltage on pin 5 of U601A to decrease. The output
voltage on pin 7 then decreases which causes the
power output of the transmitter module to decrease
and maintain a constant power output. If the power
output attempts to decrease, the opposite occurs.

The microcomputer is reset when transceiver
power is turned on and when the 5-volt supply drops
below a specific level. Reset clears several internal
registers, disables the serial ports, and restarts the
operating program. Reset prevents improper micro­computer operation resulting from low-voltage condi­tions.

Power-on reset occurs automatically for 4064
clock cycles whenever power is applied to the VDD
input of the microcomputer. Low-voltage reset is initi­ated by 5-volt regulator U805. When the 5-volt supply
drops below approximately 4.75 volts, the ERROR
output of U805 goes low. This brings the RESET input
(pin 1) of the microcomputer low which causes reset
and also halts operation for as long as it is low.

Data Input/Output Ports

The internal eight-bit data bus of the microcom­puter has three data input/output ports. These ports
have eight lines each, giving a total of 24 input/output

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CIRCUIT DESCRIPTION

lines. These ports are designated as PA, PB, and PC.
Each line of these ports can be configured for input or
output as required. There is also a fourth port
consisting of PD0-PD5 and PD7. This port can be used
for fixed inputs or if the serial ports are used, PD0­PD5 provide the serial port signals. In this applica­tion, the serial ports are used, so PD0-PD5 provide the
RDI, TDO, MISO (not used), MOSI, and SCK signals.
The following is a brief description of the functions
performed by each of these lines.

Port A

PA0 - Not used in Multi-Net versions of this trans-

ceiver because an external decoder is not supported.
With the LTR version, this pin is used as the squelch
control input from the decoder. This input can be
either active high or low to indicate when the trans­ceiver should unsquelch (enable the audio).

PA1 - Squelch input. A high on this input indicates
that a carrier is being detected.

PA2 - Low-battery detect. A low on this input indi­cates that the battery needs recharging.

PA3 - Synthesizer lock detect. A low on this input
indicates that the VCO is locked on frequency.

PA4 - Push-to-talk (PTT) detect. This input goes low
when the transmitter is keyed by the PTT switch on the
side of the transceiver or by an external PTT switch
connected through the accessory connector. When this
input goes low and transmission is allowed, the micro­computer keys the transmitter by programming the Q4
output of shift register U204 to go high (U2Q4 is
located on the mother board).

PA5 - Power off detect. This input goes high when
power is turned off by the power switch on top of the
transceiver or by a power switch connected through
the accessory connector. Although these switches are
turned off, power does not actually turn off for approx­imately 200 milliseconds because C223 on the mother
board must charge through R223. During this delay,
the microcomputer stores the current operating param­eters in the EEPROM.

PA6 - Chip select output to U802. This output goes
high when data is to be written to display controller

U802 on serial port SCK/MOSI. Refer to Section 6.5.4
for more information.

PA7 - Busy input from U802. This input goes low
when display controller U802 is busy. Refer to Section

6.5.4 for more information.

PORT B

PB0/PB1 - Generate the Multi-Net data or Conven-

tional Call Guard waveforms. R826 and R827 form a
voltage divider which provides up to four different
voltage levels from the two bits of information
produced by these outputs. When Multi-Net data is
generated, a four-step waveform provides pulse
shaping in order to obtain the desired response in the
data filter (refer to Section 6.6.2). When digital Call
Guard signaling is produced, a two-step signal is used;
and when tone Call Guard signaling is produced, a
four-step waveform is used. When no signal is being
produced, both outputs are in a high-impedance state.

PB2 - Synthesizer enable. When a positive-going
pulse appears on this output, data is latched in shift
register U353 and synthesizer U351 on the synthe­sizer module.

PB3 - Shift register U204 enable. When a positive­going pulse appears on this output, data in shift
register U204 on the mother board is latched. In addi­tion, when this output remains high, the Q outputs of
U204 are enabled.

PB4/PB5 - Used to read columns 4 and 5 of the
keypad. Refer to Section 6.5.5 for more information.

PB6 - Serial clock output to tone generator U803 and
EEPROM U804. This is a software-generated serial
clock. Data is valid on the rising edge of this clock.
Refer to Sections 6.5.2 and 6.5.3 for more information.

PB7 - Serial bidirectional data line to tone generator
U803 and EEPROM U804. Refer to Sections 6.5.2 and

6.5.3 for more information.

PORT C

PC0SPC1/PC2/PC3 - Used to read the rows of the

keypad. Refer to Section 6.5.5 for more information.

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CIRCUIT DESCRIPTION

PC4/PC5/PC6 - Used to read columns 1-3 of the
keypad. Refer to Section 6.5.5 for more information.

PC7 - Control output to display controller U802. A
high selects the command format and a low selects the
data format.

PORT D

RDI/TDO (PD0/PD1) - Asynchronous serial data

port. RDI is the receive data input and TDO is the
transmit data output. These pins provide serial data
communication with external equipment including the
RPI when programming the transceiver and the remote
control unit when the transceiver is used in mobile
applications. Data is in an NRZ format at 9600 baud.

MOSI/SCK (PD2/PD4) - Synchronous serial data
port. These outputs are used to program display
controller U802, shift register U353 on the synthe­sizer module, and shift register U204 on the mother
board. MOSI (master out, slave in) is the data output,
and SCK (serial clock) is the clock signal. The clock
rate is 1 MHz, and an eight-bit data format is used.
The data transferred into the shift registers is latched
by a positive-going pulse on the ENABLE output
(PB3) and into the display controller by a low on the
chip select output (PA6).

MISO/SS (PD3/PD5) - Synchronous serial data port
pins that are not used.

PD6 - Not assigned.

PD7 - Input for receive Multi-Net data or Call Guard

signaling.

OTHER PINS

6.5.2 EEPROM (U804)

U804 is an Electrically Erasable Programmable
Memory (EEPROM). This type of device can be
reprogrammed over and over again by the microcom­puter. Since it is also a nonvolatile memory, battery
backup is not required to maintain the stored data
when transceiver power is off or the battery is
removed. This device can store 2048 eight-bit data
words. The memory is arranged as eight 256 x 8
pages.

The AFA2 pins are not used and are tied low. A
software-generated synchronous serial port on the PB6
and PB7 outputs of the microcomputer is used to read
and write to this device. The clock rate is approxi­mately 100 kHz and data is valid on the positive-going
edge of the clock signal. The SCL input of U804 is the
serial clock and the SDA pin is the serial data input/
output. One control word is written to the device to
specify the type of operation (read or write) and the
page location, and another word specifies the location
on that page. The actual data is then transferred.

6.5.3 TONE GENERATOR (U803)

U803 generates the DTMF tones that are trans­mitted when telephone calls are placed. In addition, it
generates the supervisory tones heard in the Multi-Net
mode such as the busy and intercept tone. The serial
bus used to program EEPROM U804 also programs
this device. When a tone is to be produced, the micro­computer writes the digital code for that tone to the
tone generator. The tone is then generated and fed out
of the logic board on pin 7 and applied to both the
receive and transmit audio circuits. This allows the
tone to be heard by the user and also transmitted if
necessary.

TCMP - Audio amplifier control output. This is the
timer compare output used to disable the audio ampli­fier stages. The audio is muted when this output is
high. Receive audio is also muted by gate U203D as
described in Section 6.6.1.

IRQ - Emergency switch input. The emergency switch
is used in Multi-Net transceivers only. When this inter­rupt request input goes low, the microcomputer inter­rupts normal operation and vectors to the section of
the program which services the emergency switch.

6.5.4 DISPLAY CONTROLLER (U802)

U802 is an intelligent alphanumeric LCD (liquid
crystal display) controller/driver. It communicates
with the microcomputer through the same synchro­nous serial bus that is used to program the synthesizer
and shift register U204. The functions of the various
input and output pins are as follows:

SI (Serial Input) - Input for serial data from the
MOSI output of the microcomputer. Data on this input

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CIRCUIT DESCRIPTION

is valid on the rising edge of the clock signal on the
SCK input.

SCK (Serial Clock) - Clock signal input which
synchronizes the eight-bit data transfers.

BUSY - Handshake output which indicates when the
device is ready to receive data. This output goes low
after a byte is received and then back high when
another byte can be received.

C/D - Command/Data input. This input indicates
whether the byte of data just received is a command or
display data. A high indicates a command and a low
indicates display data.

CS (Chip Select) - A low on this input selects the
device for data input. The display is updated when this
input is high.

RESET - A low on this input after power up resets the
device much the same as microcomputer reset
described in Section 6.5.1.

key is released. They then return to the condition
described in the preceding paragraph.

6.5.6 FIVE-VOLT REGULATOR (U805), LOW­BATTERY DETECT (U806)

The output of regulator U805 is set for 5 volts by
connecting the 5-volt tap (pin 6) to the feedback input
(pin 7). The error output on pin 5 goes low when the 5­volt supply drops below approximately 4.75 volts.
This resets microcomputer (see Section 6.5.1) and
display controller.

The voltage output on pin 6 of U805 is a very
stable 1.23 volts. Therefore, it is a good reference for
low-battery detector U806. When the battery voltage
drops below approximately 6.2 volts, the noninverting
input of U806 drops below the 1.23-volt reference on
the inverting input. The output then goes low and a
low-battery condition is indicated to the microcom­puter.

6.5.7 AUDIO AMPLIFIER (U808-U810)

CL1/CL2 - Clock pins. CL1 is the input and CL2 is
the output of the internal clock oscillator.

VLCD1-VLCD3 - LCD bias supply inputs to the
internal LCD voltage controller.

S0-S31 - LCD segment driver outputs.

COM0-COM3 - LCD backplane driver outputs.

6.5.5 KEYPAD DECODING

The microcomputer detects which key is pressed
by reading the columns and then the rows of the
keypad. When no key is being pressed, the row pins
(PC0-PC3) are outputs that are continuously low, and
the column pins (PC4-PC6, PB4/PB5) are inputs in a
high-impedance state (tri-state) except when they are
periodically read.

When a key is pressed, a low is detected on the
column of that key. After a 30 millisecond debounce
delay, the row and column states reverse so that the
rows are inputs and the columns are low outputs. The
active key is then determined by which row is low.
The rows and columns remain in this state until the

CAUTION

Do not connect a meter across the internal speaker
that does not have floating inputs because grounding
either speaker terminal will seriously damage U809 or
U810.

The receive audio signal is applied to a three­stage audio amplifier formed by U808-U810. The gain
of U808 is set at about 26 by R852 and R854. R850
and R851 provide biasing, and C820 and C821
provide DC blocking, and C823 and R853 provide
stabilization. C822 causes frequencies above the audio
range to be attenuated. The output of U808 provides
drive to U809/U810 and also to an external speaker if
one is used. Power output from U808 is 125 milliwatts
with a 16-ohm load.

U809 and U810 form a push-pull audio ampli­fier. Therefore, the output voltage of one stage is
increasing while the output voltage of the other stage
is decreasing. This produces nearly twice the output
voltage swing that is possible with a single stage. The
gain is set by R857/R858, and C825/R859 and C826/

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CIRCUIT DESCRIPTION

R855 provide stabilization. Power output from U809/
U810 is 500 milliwatts with a 16-ohm load.

When a high voltage is applied to pin 8 of U808­U810, the audio is muted. The voltage on these pins is
controlled by the TCMP output of the microcomputer
and also by Q801. The microcomputer mutes the audio
when no tones are sounding and no message is being
received which conserves power. The receive audio
signal may also be muted by gate U203D as described
in Section 6.6.1.

Q801 shuts down U809 and U810 to mute the
audio to the internal speaker whenever a load of 1k
ohm or less is connected to pin 5 of the accessory
connector. This load could be an external speaker or
the system box. When Q801 turns on, 5 volts is
applied to pin 8 of U809 and U810. However, pin 8 of
U808 is still controlled by the microcomputer because
of R860, so U808 operates normally.

Q801 is controlled by several resistors located on
the mother board. The base current of Q801 flows
through R830, R232, R234, and R233. When a load of
1k ohm or less is connected to the external speaker
line, the voltage at the junction of R231 and R233
drops to a level which causes Q801 to turn on. R234,
C245, and R232 provide isolation between the low and
high level receive audio lines.

6.6 RECEIVE AUDIO AND DATA PROCESSING

6.6.1 AUDIO AND DATA ROUTING (U551, U555)

6.6.2 RECEIVE AUDIO PROCESSING (U553A/B)

The receive audio and data signal from detector
U521 on the IF module is applied to the data filter
module on pin 3. Gates U551C and U555A pass the
signal in the receive mode and block it in the transmit
mode. Therefore, in the transmit mode, U551C
prevents the receive audio signal from interfering with
the data signal, and U555A blocks the transmit data
signal from the receive audio circuit. Gate U555B
passes the DC bias signal from R579/R582 in the
transmit mode. This maintains bias on the audio line to
prevent an audible “click” when going from the
transmit to the receive mode.

The receive audio signal is then fed to a bandpass
filter formed by U553A, U553B, and several resistors
and capacitors. This filter passes frequencies from
300-3000 Hz and provides de-emphasis of the audio
signal. This attenuates LTR or Multi-Net data, Call
Guard signaling, and high-frequency harmonics.

The signal is then fed to audio gate Ur~03D
located on the mother board. This gate is controlled by
shift register U204 (refer to Section 6.7.3). The audio
is blocked by this gate whenever no message intended
for the user is being received. The receive audio signal
is also muted at the audio amplifier as described in the
preceding section. On the output of U203D, the signal
is combined with the DTMF or supervisory tones if
present. The signal is then fed to the volume control
and to the audio amplifier located on the logic board
(refer to preceding section).

Several gates on the data filter module are used
to control routing of the audio/data signal in the
receive and transmit modes. These gates are controlled
by the signal on pin 5 of the module. In the receive and
test modes, this signal is low; in the transmit mode, it
is high. When the control input of a gate is high, it
passes the signal; and when it is low, it blocks the
signal. Gate U551A functions as an inverter. The func­tion of these gates in the receive, transmit, and test
modes is described in the following information.

6.6.3 RECEIVE AND TRANSM1T DATA PRO­CESSING (U553A/B, U552A-U552D)

Receive Mode Processing

In the receive mode, gate U551B blocks any
transmit data signal and gate U551C passes the receive
data/audio signal. This routes the receive LTR or
Multi-Net data and also Call Guard signal to the data
filter circuit formed by U552A/B and several resistors

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CIRCUIT DESCRIPTION

and capacitors. This is a low-pass filter which attenu­ates voice and harmonic frequencies above the data
band.

The passband of the filter is controlled by Q551.
When LTR or Multi-Net data, digital Call Guard data,
or a low-frequency Call Guard tone is transmitted or
received, Q551is turned on and the cutoff frequency is
approximately 150 Hz. However, when a high­frequency Call Guard tone is transmitted or received,
Q551is turned off and the cutoff frequency is approxi­mately 190 Hz. Turning Q551 on switches additional
capacitance into the filter which lowers the cutoff
frequency.

From the filter the receive data signal is applied
to a DC restoration circuit formed by U552C and
U552D. Gate U555D passes the signal to the DC
restoration circuit in the receive mode. The function of
the DC restoration circuit is to convert the signal from
AC floating at half the supply voltage to a digital
signal at 0- and 5-volt levels that can be read by the
microcomputer. U552C is a standard noninverting
amplifier with a gain of approximately 2.7 set by R555
and R560 (R555is AC grounded by C565). Diodes
CR551A and CR551B charge and discharge C565 to
establish a DC reference on U552, pin 6 and U552D,
pin 9. This reference is the average of the positive- and
negative-going alternations of the data signal.

The amplified data signal is applied to pin 10 of
U552D. When this level rises above the reference
level on pin 9, the output on pin 8 goes high (5 volts).
Conversely, when the data signal falls below the refer­ence level, the output goes low (0 volts).

Gate U555D blocks the signal in the transmit
mode so that it is not fed to the DC restoration circuit.
Gate U555C passes the DC bias signal from R579/
R582 in the transmit mode in order to maintain the DC
level on pin 5 of U552. This ensures that the DC resto­ration circuit is ready to receive data when the receive
mode is again enabled.

Test Mode Processing

In the test mode, the group select switch selects
different modulation schemes in the transmit mode as
described in Section 2.15. Group 1 selects a 134 Hz
square wave with the data filter bypassed, and Group 2
selects the same 134 Hz signal with the data filter
utilized. When Group 1 is selected, the gates are
configured as in the receive mode described in the
preceding information. The transmit data signal is then
fed through U551D and applied directly to the transmit
audio circuit without going through the data filter. This
passes harmonic frequencies so that a wide range of
frequencies are available for setting modulation
balance. When Group 2is selected, the gates are in the
normal configuration for the transmit mode.

6.6.4 TRANSMIT AUDIO PROCESSING

High-Pass Filter (U601B)

The microphone audio signal is applied to a
high-pass filter formed by U601B and several resistors
and capacitors. This filter has a –3 dB cutoff frequency
of approximately 300 Hz to attenuate frequencies
which could cause interference with the Multi-Net
data or Call Guard signals.

Transmit Mode Processing

In the transmit mode, gate U203B on the mother
board and gate U551B on the module pass the signal,
and gates U551C and U555A block the signal. There­fore, the transmit data or Call Guard signal on pin 6 of
the module is applied to the filter. The operation of
this filter was described in the preceding paragraphs.
This filtering attenuates harmonics present in the
synthesized waveform produced by the PB0 and PB1
outputs of the microcomputer. The output of the data
filter is fed through gate U302B and applied to pin 4 of
the transmit audio/power control module.

Revised February 1997
Part No. 001-8560-381

The signal is then fed through gate U602D which
is controlled by the Q1 output of U204 on the mother
board. A high on the control input of this gate passes
the signal and a low blocks the signal. When micro­phone audio is being transmitted, the Q1 output is
high. The 7.5-volt supply applied through R610 is
used to increase the 5-volt high level from U204 that is
applied to the gate. If DTMF tones are being trans­mitted, the microphone audio signal is blocked by this
gate because the Q1 output of U204 is low. This
prevents feedback of tones from the speaker to the
microphone. The microphone audio signal is also
blocked at other times such as in the receive mode to
prevent modulation of the receive signal.

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CIRCUIT DESCRIPTION

Limiter (U603A)

C607 and R615 on the input of U603B provide
pre-emphasis of the transmit audio signal. U603A
functions as a limiter to prevent overmodulation
caused by high input levels from the microphone. This
stage is an amplifier which limits by saturating. A 2.6­volt bias to this stage and also U601B is produced by
voltage divider R613/R614.

Combiner (U603B)

U603B combines the transmit audio and tone
signal with the transmit data signal. The output of this
stage is the difference between the input signals. The
gain of the input signals is set by R621, R623, R622,
R619, and R620. Capacitor C613 causes frequencies
above approximately 3 kHz to be attenuated. The
output signal is applied across potentiometer R624
which sets the deviation level. The data and micro­phone audio levels are preset by fixed resistors, so are
not adjustable.

Low-Pass Filter (U603C, U603D)

U603C, U603D, and several resistors and capaci­tors form a low-pass splatter filter which attenuates
frequencies above approximately 3 kHz. This prevents
adjacent channel interference caused by harmonic
frequencies resulting from amplitude limiting. The
output from the filter is then fed to the synthesizer
where it frequency modulates the transmit signal.

6.7 MOTHERBOARD POWER SWITCHING,

REGULATORS, AND SHIFT REGISTER

R212. This reverse biases CR204 and also applies a
high voltage to the PA5 input of the microcomputer
through pin 11 of the logic board. C223 then begins
discharging through R223 which keeps Q201 turned
on for a short time after the power switch is turned off.
During this delay, the microcomputer stores the
current transceiver operating parameters in the
EEPROM.

6.7.2 TRANSMIT SWITCH (Q202, Q204)

Q202 functions as an inverter and driver. When
the Q4 output of the shift register goes high, Q202
turns on. This turns on Q204 and 7.5 volts appear on
the collector. R213 and R215 ensure that these stages
turn off when the Q4 output of the shift register goes
low.

6.7.3 SHIFT REGISTER (U204)

Shift register U204 is used as a port expander to
provide additional microcomputer control outputs.
Information is loaded into this device using the same
serial bus used to program the synthesizer and display
controller. Data on the DATA input is clocked into
U204 by a positive transition of the CLOCK input.
The data is latched into the register by a negative tran­sition of the ENABLE input. This input functions as a
chip select to select this device as the destination for
information on the data bus. After data is loaded into
this device, the ENABLE line is held high which
causes gate U203A to conduct. This places a logic 0
on pin 15 which enables the Q outputs.

6.7.4 REGULATORS (U201, U202)

6.7.1 POWER SWITCHING (Q201, Q203)

The switched 7.5-volt supply is controlled by
Q201 which is a P-channel MOSFET. This transistor
turns on when the gate is low and off when it is high.
When the transceiver on-off switch or an external on­off switch is turned on, Q203 is turned on by 7.5 volts
applied through R222 and R211. CR204 is then
forward biased and Q201 turned on.

When both the transceiver and external on-off
switches are off (open), Q203 turns off. The collector
then goes high because 7.5 volts is applied through

Five-volt regulator U202 functions similar to
U805 described in Section 6.5.6. Regulator U201 is
similar except that resistor network R219 and R220 is
used to provide the feedback voltage instead of the 5­volt tap. The values of these resistors are chosen to
provide an output voltage of 5.7 volts. The shutdown
input (SD) is connected to the Q2 output of shift
register U204. When this input is high, the regulator
turns off and the output goes to zero volts. This input
is currently not used, so it is always low.

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SECTION 7 SERVICING

SERVICING

7.1 GENERAL

7.1.1 PERIODIC CHECKS

This transceiver should be put on a regular main­tenance schedule to ensure that it continues to operate
properly. Important checks are receiver sensitivity and
transmitter frequency, deviation, and power output.
Performance tests for checking these and other param­eters are located in Sections 8.5 and 8.6. It is recom­mended that the transceiver be checked at least
annually.

7.1.2 SCHEMATIC DIAGRAMS AND

COMPONENT LAYOUTS

Schematic diagrams and component layouts for
the various modules used in this transceiver are
located in the back of this manual. There are sche­matics for the synthesizer, receiver, transmitter, audio/
logic, and mother board. Modules performing a similar
function are shown on the same schematic. For
example, the receiver schematic shows the RF ampli­fier/mixer and IF modules. The mother board sche­matic shows the interconnections between the various
modules and also how the various modules are
grouped together for schematic purposes. Component
layouts are located with the schematic diagrams.
These layouts permit easy location of components and
measurement points.

7.1.3 REPLACEMENT PARTS

A replacement parts list containing the Johnson
part numbers of aU parts used in this is transceiver is
located in Section 9. The parts for all modules are
combined together in one listing. Parts are listed
alphanumerically according to designator. For infor­mation on ordering parts, refer to Section 1.9. Also
included in Section 9 are exploded views which show
the location of mechanical parts.

7.1.4 TEST MODE

This transceiver has a test mode that must
usually be selected to perform testing. The test mode is

described in Sections 3.15 and 8.1. The test mode is
especially useful if the transceiver is programmed for
Multi-Net operation because the logic normally
inhibits operation unless a data handshake with a
Multi-Net repeater is completed.

7.2 MODULE TROUBLESUOOTING

7.2.1 TROUBLESHOOTING TO MODULE LEVEL

This transceiver consists of ten separate modules,
a logic board, and a mother board. The logic board and
all ten modules connect to the mother board. All plug
into the mother board except the power amplifier and
TCXO modules which are soldered in place. There­fore, an inoperative transceiver can usually be returned
quickly to service by simply replacing a module. (A
ground strap must be unsoldered to replace some of
the modules.)

The easiest way to determine if a module is
defective may be to replace it with a new one. The
servicing information which follows can also be used
to measure module input and output signals to deter­mine if a module is operating properly. The first thing
to check is the supply voltages that are indicated on
the schematic diagram. Other voltages shown on the
schematic diagram should then be checked.

Field repair of modules may be difficult because
components and test points are generally not acces­sible while the module is installed. Therefore, a special
extender card or test fixture may be required to
perform troubleshooting with the module operating.
Factory repair of some of the modules may be avail­able. Contact Customer Service as described in
Section 1.7 for more information.

NOTE: The VCO and a portion of the synthesizer
module and mother board have been coated to protect
against moisture. Therefore, a sharp probe may be
required to pierce this coating when servicing these
components.

7-1

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Part No. 001-8560-381

SERVICING

7.2.2 VCO AND TCXO MODULES NOT SERVICEABLE

The VCO and TCXO modules cannot be
repaired in the field. With the VCO module, a ceramic
substrate is used and a tuning stub is laser trimmed at
the factory to set the VCO for the correct frequency. It
is also coated to protect against moisture. The TCXO
is not field serviceable because if a part is changed, a
factory recalibration must be performed to ensure that
it stays within its 2.5 PPM tolerance.

CAUTION

The ceramic substrate of the VCO and antenna filter
modules may break if the module is dropped on a hard
surface or flexed excessively.

7.2.3 ACCESSING MODULE PINS

The signals on all input and output pins of the
modules and logic board can be measured on the
bottom of the mother board. The bottom of that board
is accessed by removing the back cover of the trans­ceiver. The front cover must be removed to access the
modules and also components on the logic board.
However, removing the front cover unplugs the logic
board which is attached to the inside of that cover.
Therefore, an extension test cable such as Part No.
023-8560-910 shown in Table 1-2 must be used to
operate the transceiver with the front cover unplugged.

7.4 CMOS HANDLING TECHNIQUES

Several of the integrated circuits used in this
transceiver, including microcomputer U801, are
CMOS devices. The part number of CMOS integrated
circuits usually has a ~3t as the fourth digit (544-3m­m). CMOS devices have a very high open circuit
impedance, so are particularly susceptible to damage
from static charges. Damaging static charges may be
present even if no static arcs are observed. In addition,
damage may not be immediately apparent because the
device may only be weakened. When handling CMOS
devices, observe the following precautions:

• Before touching the transceiver or a CMOS device,

discharge any built-up static charge on your body by
touching a good earth ground.

• Ground all test equipment and make sure that the

soldering iron tip is grounded.

• Connect ground leads before test probes. Leave the

CMOS device in its conductive shipping container
until it is inserted in the PC board.

Once the device is installed in the PC board, it is
protected by internal diode protection circuits, so the
chance of damage is reduced. A service bench protec­tion kit, Part No. 299-0026-001, can be ordered from
the Service Parts Department. This kit includes a
conductive mat, wrist strap, and grounding strap with a
1 megohm resistor to eliminate static build-up on the
body.

7.3 SURFACE-MOUNTED COMPONENTS

Surface-mounted components are used exten­sively in this transceiver. Because of the small size of
these components and the PC board traces they are
mounted on, special care must be used when replacing
them. Multi-leaded components such as integrated
circuits must usually be removed using a heat gun or
some other type of heat source that heats the entire
component. Care must then be used so that any nearby
heat-sensitive components are not damaged. Surface­mounted components should not be reused since they
may be damaged by the unsoldering process. For more
information on replacing surface-mounted devices,
refer to the Surface-Mounted Device Handbook, Part
No. 001-0576-001.

Revised February 1997
Part No. 001-8560-381

7.5 SYNTHESIZER TROUBLESHOOTING

7.5.1 INTRODUCTION

When there is a synthesizer malfunction, the
VCO is usually not locked on frequency. When an
unlocked VCO is detected by the lock detector circuit,
pin 15 of the synthesizer module goes high (5 volts).
When this unlock indication is detected by the micro­computer, it will not allow the transmitter to be keyed
or the receiver to unsquelch. In addition, “SYN ERR”
is indicated in the upper part of the display.

When the VCO is unlocked, the fR and fV inputs
to the phase detector are usually not in phase (refer to
Figures 6-1 and 6-2 in Section 6). The phase detector

7-2

SERVICING

in U351 then causes the VCO control voltage to go to
the high or low end of its operating range. This in turn
causes the VCO to oscillate at the high or low end of
its frequency range.

As shown in Figure 6-1 in Section 6, a loop is
formed by VCO Q301, prescaler U352, and the N
counter and phase detector in U351. Therefore, if any
of these components begin to operate improperly,
improper signals appear throughout the loop.
However, correct operation of the counters can still be
verified by measuring the input and output frequencies
to check the divide number.

Proceed as follows to check the input and output
signals of the synthesizer modules to determine if they
are operating properly.

7.5.2 TCXO MODULE

Check the signal at pin 5 of the TCXO. It should
be 14.8375 MHz at a level of approximately 1.5 V P-P.
If the TCXO is defective, it is not serviceable and
must be replaced with a new unit as described in
Section 7.2.2.

7.5.3 VCO MODULE

NOTE: If the VCO module is defective, field repair
should not be attempted for the reasons stated in
Section 7.2.2.

Output Level

The output levels on pins 10 and 12 of the VCO
module can be measured with an RF voltmeter or
some other type of high-impedance meter. The
minimum output levels should be as follows:

Pin 10 = 5 dBm

Pin 12 = 0 dBm

Control Voltage

Check the DC voltage at pin 8 of the VCO
module with a channel near the center of the band
selected. If the VCO is locked on frequency, it should
be a steady DC voltage near 6.5 volts. If it is not
locked on frequency, it should be near the lower or
upper end of its range (1 or 12 volts).

Output Frequency

Check the VCO frequency at pin 10 or 12. If the
VCO is locked on frequency, it should be stable as
follows for the receive and transmit modes:

Rx Mode VCO Freq =

Tx Mode VCO Freq =

Chan Freq – 44.9625 MHz

2

Channel Frequency

2

If the VCO is not locked on frequency, the VCO
control voltage at pin 8 is probably near 1 or 12 volts.
The VCO frequency should then be as follows:

Pin 8 near 1 volt

- VCO frequency should be less than

403 MHz.

Pin 8 near 12 volts

- VCO frequency should be greater

than 413 MHz.

The VCO control voltage can also be controlled
using a power supply if the synthesizer module is first
removed. Connect the + lead of the power supply to
pin 8 of the VCO module. At 3 volts the frequency
should be about 403 MHz and then it should increase
linearly up 10 volts when it should be approximately
413 MHz.

Talk-Around Switch

The levels on pins 1 and 2 of the VCO module
should be approximately as follows in the standard and
talk-around modes:

Mode Pin 1 Pin 2

Standard 4.5V 0.5V
Talk-around 4.5 V 0.5V

7.5.4 SYNTHESIZER MODULE

Introduction

To check the talk-around, VCO control, and
VCO RF input signals, refer to the preceding section.
A locked or unlocked condition should be indicated by
those checks. The lock detect output on pin 15 should
then be as follows:

7-3

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Part No. 001-8560-381

SERVICING

VCO Pin 15

In lock 0.5 volt
Out of lock 5 volts

If further troubleshooting of the synthesizer
module is desired in order to isolate a problem to a
defective component, refer to the information which
follows. However, to access components on this
module, an extender card of some type is probably
needed and a shield must be removed.

If a problem seems to be caused by the control
logic, check transceiver programming to make sure
that is it correct before performing other logic trouble­shooting. The A and N counter divide numbers
referred to in the following information can be calcu­lated as described in Section 7.5.6.

Synthesizer U351 Troubleshooting

Reference Counter - If the TCXO checked out okay
as described in Section 7.5.2, the reference counter in
U351 can be checked. The reference counter divides
by 2374 for all channels. Dividing the TCXO
frequency of 14.8375 MHz by 2374 produces an
output from the reference counter of 6.25 kHz. This
frequency can be measured at U351, pin 13, and it
should be present even if the VCO is not locked on
frequency. If the TCXO frequency is correct and the
frequency on pin 13 is not correct, U351 may be
defective or the control logic may be programming the
reference counter with the wrong divide number.

N Counter - To check the operation of the N counter,
the input and output frequencies can be measured to
check the divide number. The divide number for the
channel you have selected is calculated as described in
Section 7.5.6. The input and output frequencies can be
measured as follows:

U351, pin 8 Frequency
U351, pin 3 Frequency

= N Counter Div No.

measured. If the VCO is not locked on frequency, the
input and output frequencies may be different, but the
divide number should be the same.

3.18125 MHz

6.25 kHz

= 509 6.25 kHz

NOTE: If a changing control voltage is causing the
VCO frequency to be unstable, momentarily ground
the control line at pin 2 of the module.

The preceding frequencies may not be exactly as
calculated due to counter accuracy and resolution limi­tations. If the divide number is not correct, U351 may
be defective or the control logic may be programming
the N counter with the wrong number. If the divide
number is correct, continue the checks which follow.

Phase Detector - When the VCO is not locked on
frequency, the fR and fV inputs to the phase detector
are probably not the same frequency. Measure the
frequency at fR (pin 13) and fV (pin 3) and then check
the phase detector outputs (DOWN and UP pins). If
the phase detector is operating properly, these outputs
should be as follows:

fV greater than fR

- The negative-going pulses on the
DOWN output (pin 15) should be much wider than the
negative-going pulses on the UP output (pin 16). The
DC voltage on pin 2 of the module should be near 1
volt.

fV less than fR

- The negative-going pulses on the UP
output (pin 16) should be much wider than the nega­tive-going pulses on the DOWN output (pin 15). The
DC voltage on pin 2 of the module should be near 12
volts.

If the preceding phase detector output signals are
not measured when the VCO is out of lock, U351 or
the charge pump circuit may be defective. If the phase
detector and charge pump are operating properly,
check the lock detector and prescaler as described in
the following information.

For example, the N counter divide number for
channel 375 (receive) is 509. If the VCO is locked on
frequency, the following frequencies should be

Revised February 1997
Part No. 001-8560-381

When the VCO is locked on frequency, the
following waveforms should be observed at the points
indicated (all pulses should occur simultaneously

7-4

SERVICING

Prescaler U352 Troubleshooting

The prescaler divide number can be checked by b
measuring the input and output frequencies. The t
prescaler divide number is calculated as follows.
(Refer to Section 7.5.6 to calculate A and N counter
divide numbers.)

Prescaler divide number =

Lock Detector - When the VCO is locked on
frequency, the waveform at U351, pin 7 should be as
follows. The lock detect output on pin 15 of the
module should then be low. When the VCO is
unlocked, the negative-going pulses should be much
wider than those shown and the output on pin 15
should be high (5V).

Modulus Control Signal - The frequency of the
modulus control output on U351, pin 12 should be
equal to the N counter output frequency on pin 3
(either in or out of lock). When the VCO is in lock,
this frequency should be 6.25 kHz.

128 +

A Counter Divide Number
N Counter Divide Number

For example, for channel 375 (receive):

Prescaler divide number =

128 + 80/509 or 128.1572

Measure the prescaler input frequency at pin 6 of
the synthesizer module. Then measure the output
frequency at pin 4 of U352 and calculate the divide
number. If the VCO is not locked on frequency, the
divide number should still be correct. The measured
frequencies may not be exactly as calculated due to
counter accuracy and resolution limitations. For
example, for channel 375 (receive) with the VCO
locked on frequency, the following frequencies should
be measured:

407.700 MHz (pin 6)

3.18125 MHz (pin 4)

= 128.1572

The duty cycle of the modulus control signal
determines the divide number of the prescaler. The
duty cycle should be as follows:

T1
T2

A Counter Divide Number

=

N Counter Divide Number

If the modulus control signal is not correct, U351
may be defective or the logic may not be programming
the correct divide number.

If the divide number is not correct, the modulus
control signal from U351 may not be correct. To over­ride this signal, tie pin 6 of U351 high and low and
check the divide number. The divide number should be
as follows:

Pin 6 high (5V) = Divide by 128
Pin 6 low (0V) = Divide by 129

If the divide number is now correct, U352 is
probably okay and the problem may be with U351.

Revised February 1997

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VCO

Freq

=

860.3625 – 44.9625 MHz

2

= 407.700 MHz

N Counter Divide No. =

407.700 MHz

0.8

= 509.625

VCO Freq (MHz)

0.00625

– (N Counter Div No. x 128)

407.700 MHz

0.00625

– (509 x 128)

7.5.5 DOUBLER/FILTER MODULE

Check the input and output signals as follows:

Input Signal - The signal on pin 7 can be checked as
described in Section 7.5.3 under “Output Level” and
“Output Frequency”.

Output Signal -The output signal should be twice the
VCO frequency at a level of approximately 0 dBm.

7.5.6 CALCULATING N AND A COUNTER DI­VIDE NUMBERS

N COUNTER

For example, for channel 375 (receive):

7.6 RECEIVER SERVICING

7.6.1 RF AMPLIFIER/MIXER MODULE

Check the DC voltages at pins 7 and 8. To deter­mine if this module is defective, inject the signals at
the output and input as shown on the schematic
diagram. If this indicates that this module and the IF
module are operating properly, the problem may be in
the antenna switching circuitry in the transmitter.

7.6.2 IF MODULE

If the tests in the preceding section indicated a
problem with the IF module, first check the 5-volt
supply on pin 3. Then check the TCXO signal on pin 6
to make sure that it is 14.8375 MHz at a level of
approximately 1.5 V P-P. To check the squelch and
audio outputs, measure the audio and noise voltages
shown on the schematic diagram.

7.7 TRANSMTTER SERVICING

Integer (whole number) of 509.625 = 509

“A” COUNTER

“A” Counter Divide Number =

For example, for channel 375 (receive):

“A” Counter Divide Number =

A = 65,232 – 65,152
A = 80

NOTE: To determine the N and A counter divide
numbers for 12.5 kHz offset channels from 1-600,
calculate using a VCO frequency 6.25 kHz below that
used for the standard channel frequency. Channels
601-910 are already numbered for a 12.5 kHz spacing.

Revised February 1997
Part No. 001-8560-381

7.7.1 GENERAL

To isolate a transmitter problem to a defective
module or stage, measure the DC and RF voltages
shown on the schematic diagram.

7.7.2 REPLACING TRANSM1TTER MODULE

a. To replace the transmitter module, the rubber PTT/

auxiliary/light switch assembly on the side of the
transceiver must first be removed. Proceed as fol­lows:

b. Unsolder the ground strap from the transmitter mod-

ule shield and bend it out of the way.

c. Unplug the transmit audio/power control module

adjacent to the transmitter module. Also unsolder
the transmitter module pins and shield.

d. Remove the two E clips (HW11) on the inside of the

chassis that hold the switch assembly (MP4/S1) in
place (refer to the exploded view in Section 9).

e. Carefully pull the switch assembly out enough to

access the transmitter module screws (be careful not

7-6

SERVICING

to break the flex circuit traces near where they attach
to the switch board). Remove the old module.

f. Apply thermal grease to the new module and install

it by reversing the above procedure.

7.8 AUDIO/LOGIC SERVICING

7.8.1 LOGIC BOARD SERVICING

CAUTION

Do not connect test equipment to the speaker that
does not have floating inputs. Grounding either
speaker terminal will seriously damage the audio
amplifier.

To isolate a problem in the audio amplifier
section, measure the AC voltages shown on the sche­matic diagram. If a problem is suspected with the
digital circuits such as the microcomputer or display
controller, several of the input and output signals can
be checked. The signals on these pins are described in
Section 6.5.

If the microcomputer or display controller must
be replaced, it may be difficult to do so in the field
because of the miniature size and the large number of
leads of these surface-mounted components.
Replacing the display may also be difficult because
contact surface cleanliness and correct pressure on the
Z-strip are very important for proper operation. There­fore, if there is a problem with these parts, the entire
logic board should probably be replaced. If the
EEPROM is defective, an error will usually occur
during programming. Refer to Section 4.5 for more
information.

7.8.2 DATA FILTER/RECEIVE AUDIO MODULE

First check the 5-volt supply at pin 4. Also verify
that the voltage at pin 8 is high (5 volts) except when
transmitting or receiving a Call Guard tone above
approximately 130 Hz. The voltage at pin 5 should be
high in the transmit mode and low in the receive mode
and when Group 1 of the test mode is selected.

To check bandpass filter U553A/B, modulate a
receive signal with 1 kHz at 3 kHz deviation and
measure the voltages shown on the schematic diagram.

To check the data filter and DC restoration
circuits, modulate the receive signal with a 100 Hz at 1
kHz deviation and measure the voltages shown on the
schematic diagram.

7.8.3 TRANSMIT AUDIO/POWER CONTROL

MODULE

NOTE: The power control part of this module is
shown on the transmitter schematic.

Check the following DC supply voltages:

Pin 2 - 5.5V
Pin 10 - 7.5V unswitched
Pin 11 - 7.25V in transmit

To check the operation of the transmit audio
stages, inject a 200 mV rms, 1 kHz signal at the micro­phone input (pin 5 of the accessory connector). Also
select Group 2 of the test mode to generate a data
signal. The voltages and waveforms measured should
be similar to those shown on the schematic diagram.

7.9 SURFACE MOUNTED DEVICES (SMDs)

7.9.1 SERVICING TECHNIQUES

Most of the components used in this transceiver
are the surface mounted type. Since these components
and the circuit traces on which they are mounted are
very small in size, special care must be used when they
are replaced. Multi-leaded components such as inte­grated circuits must usually be removed using a heat
gun or some other type of heat source that heats the
entire device. Take care so that nearby components are
not damaged. Surface mounted components should not
be reused since they may be damaged by the unsol­dering process.

7.9.2 IDENTIFYING SMD RESISTORS

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Part No. 001-8560-381

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0 = 0
1 = 10
2 = 100
3 = 1000
4 = 10,000
5 = 100,000
6 = 1,000,000
7 = 10,000,000

8 = .01
9 = .1

Multiplier

Value in ohms

X X X

The value of resistors is indicated by a number
printed on the resistor. A three-digit number is used to
identify ±5% and ±10% resistors, and a four-digit
number is used to identify ±1% resistors. Refer to the
following information.

± 5% And ± 10% Resistors (P.N. 569-0115-

XXX)

The three-digit number used to identify ±5% and
±10% resistors corresponds to the last three digits of
the Transcrypt part number. This number is derived as
follows. For example, “273” indicates a 27k ohm
resistor and “339” indicates a 3.3 ohm resistor.

± 1% Resistors (P.N. 569-0111-xxx)

Some resistors with a ±1% tolerance are identi­fied by a four-digit number and others may not have a
marking. When identified with a four-digit number,
the first three digits are the value and the fourth is the
multiplier. For example, “5761” indicates a 5.76k ohm
resistor.

7.9.3 SMD CAPACITOR IDENTIFICATION

Ceramic SMD Capacitors (P.N. 510-36XX-

xxx)

Ceramic SMD capacitors are identified using
either an American or Japanese EIA standard. The
American standard uses a single letter or number to
indicate the value, and the color of this letter or
number to indicate the multiplier. The Japanese stan­dard uses a letter to indicate the value followed by a
number to indicate the multiplier. The values for both
standards are shown in the following table. For
example, if there is a single black “E” on the capacitor,
it uses the American standard and its value is 15 pF.

Revised February 1997
Part No. 001-8560-381

The same value is identified with the Japanese stan­dard by “E1”.

The Japanese standard may also utilize a bar to
indicate the temperature coefficient. The following
coefficients are indicated by this bar. For example,
“A2” indicates a 100 pF NPO capacitor.

XX

= NPO XX = N150 XX = N220

XX

= N330 XX = N470 XX = N750

|XX = X7R

Table 7-1 Ceramic SMD Capacitor Identification

American EIA Standard Japanese EIA Standard

First Letter/

Number

A10A1.0

B11B1.1

C12C1.2

D13D1.3

E15E1.5

H16F1.6

I18G1.8

J20H2.0

K22 J2.2

L24K2.4

N27L2.7

O30M3.0

R33N3.3

S36P3.6

T39Q3.9

V43R4.3

W47 S4.7

X51T5.1

Y56U5.6

Z62V6.2

368W6.8

475X7.5

782Y8.2

991Z9.1

7-8

Va lu e

(pF)

First Letter/

Number

Va lu e

(pF)

SERVICING

Table 7-1 Ceramic SMD Capacitor Identification

American EIA Standard Japanese EIA Standard

Color

Orange 0.1 0 1

Black 1 1 10

Green 10 2 100

Blue 100 3 1000

Violet 1000 4 10,000

Red 10,000 5 100,000

Multi-

plier

Second

Number

Multi-

plier

Tantalum SMD Capacitors (P.N. 510-26xx-xxx)

Tantalum SMD capacitor identification varies
with vendor and physical size of the capacitor. The
positive (+) end is usually indicated by a colored band
or beveled edge. The value and voltage may be indi­cated by printing on the capacitor or by using a special
code.

7.9.4 SMD INDUCTOR IDENTIFICATION

SMD inductors (P.N. 542-9000-xxx) use three
colored dots to indicate the value. The two dots on the
left side indicate the first and second digits of the
value in nanohenries, and the single dot on the right
side indicates the multiplier (see Table 7-2). For

example, brown, black, and red dots indicate a value
of 10 nH x 100 which is 1000 nH (1.0

µH). The last

three digits of the part number are also the value and
multiplier.

Table 7-2 SMD Inductor Identification

Color 1st Digit 2nd Digit

Black 0 0 1 (7)
Brown 1 1 10 (8)
Red 2 2 100 (9)
Orange 3 3 1000 (0)
Yellow 4 4 10,000 (1)
Green 5 5 100,000 (2)
Blue 6 6 --­Violet 7 7 --­Gray 8 8 --­White 9 9 0.1 (6)

Multiplier

(Last PN Digit)

7.9.5 TRANSISTOR/DIODE IDENTIFICATION

Surface mounted transistors and diodes are identi­fied by a special number. Refer to page 10-1 for more
information.

7-9

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Revised February 1997
Part No. 001-8560-381

7-10

ALIGNMENT PROCEDURE AND PERFORMANCE TESTS

SECTION 8 ALIGNMENT PROCEDURE AND PERFORMANCE TESTS

8.1 GENERAL

8.1.1 INTRODUCTION

The alignment described in this section may be
required if repairs are made that could affect the
factory alignment. To perform this alignment, the test
mode described in the next section must be selected. In
addition, the following cables and connectors are
required:

a. Extension Test Cable, Part No. 023-8560-910, or a

similar cable is needed to operate the transceiver
with the logic board unplugged from the mother
board. This cable connects between the 24-pin con­nectors on these boards. The logic board is mounted
to the inside of the front cover and must be
unplugged to access the adjustment points.

b. A test cable should be fabricated to allow signals to

be injected and measured at the accessory connec­tor. A diagram of this cable is shown in Figure 8-1.
The connector is available in Connector Kit, Part
No. 023-5810-109.

c. A female SMA connector (with outside threads) is

needed to connect equipment to the antenna jack.
An SMA-BNC adapter is listed in Table 1-2.

8.1.2 TEST MODE

Introduction

This transceiver has a test mode that is selected to
perform this alignment. The test mode is used because
the transceiver cannot be keyed or unsquelched in the
LTR mode unless a data handshake is completed. The
test mode is entered by turning transceiver power on
with the TxD and RxD pins (10 and 13) of the acces­sory connector shorted together. The normal operating
mode is automatically selected again when power is
turned on without those pins shorted. The following is
a summary of test mode operation. Refer to Section

3.23 for more test mode information.

Figure 8-1 Test Cable Fabrication

Test Channels

Test channels are programmed into the trans-

ceiver when it is programmed as described in Section

4. The following test channels are programmed if the
default channels are not changed.

Table 8-1 Default Test Channels

System Channel System Channel

117420

21208480

31809540

4 240 10 600

5 300 11-14 Not Select-

6360

able

8-1

Revised February 1997

Part No. 001-8560-381