Adtran TRACERT1L7, TRACERT1L8 User Manual

61280.003L1-1B PAGE I

TRACER USER’S MANUAL

6/18/98

PAGE II 61280.003L1-1B

RADIO FREQUENCY INTERFERENCE STATEMENT

This equipment has been tested and found to comply with the limits for
an intentional radiator, pursuant to Part 15, Subpart C of the FCC Rules.
This equipment generates, uses, and can radiate radio frequency energy.
If not installed and used in accordance with the instructions, it may
cause interference to radio communications.

The limits are designed to provide reasonable protection against such
interference in a residential situation. However, there is no guarantee
that interference will not occur in a particular installation. If this
equipment does cause interference to radio or television reception, which
can be determined by turning the equipment on and off, the user is
encouraged to try to correct the interference by one or more of the
following measures:

• Reorient or relocate the receiving antenna of the affected radio or
television.

• Increase the separation between the equipment and the affected
receiver.

• Connect the equipment and the affected receiver to power outlets
on separate circuits.

• Consult the dealer or an experienced radio/TV technician for help.

W A R N I N G

Changes or modifications not expressly approved by ADTRAN
could void the user’s authority to operate the equipment.

SHIELDED CABLES

A shielded-type power cord is required in order to meet FCC emission
limits and also to prevent interference with nearby radio and television
reception when using the AC voltage adapter. It is essential that only
the Adtran-provided power cord be used.

FCC OUTPUT POWER RESTRICTIONS

The FCC does not require licensing to implement this device. However,
the FCC has established restrictions regarding maximum output power
and the adjustments required when employing directional gain antennae.
(Refer to “Setting the Transmitter Power” in Section 2 of this manual).
These restrictions are detailed in FCC Part 15.247 (b)(1), (b)(3)(i), and
(3)(iii). It is the responsibility of the individuals designing and
implementing the radio system to assure compliance with these and any
other pertinent FCC Rules and Regulations. This device must be
professionally installed.

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61280.003L1-1B PAGE III

EXPOSURE TO RADIO FREQUENCY FIELDS

This device is designed to provide a maximum power output of 100 mW.
This level of RF energy in itself is below the Maximum Permissible
Exposure (MPE) levels specified in FCC OET 65:97-01. The installation
of high gain antenna equipment in the system configuration may create
the opportunity for exposure to levels higher than recommended for the
general population at a distance less than one meter from the center of
the antenna. The following precautions must be taken during installation
of this equipment:

• The installed antenna must not be located in a manner that allows
exposure of the general population to the direct beam path of the
antenna at a distance less than one meter. Installation on towers,
masts, or rooftops not accessible to the general population is
recommended; or

• Mount the antenna in a manner that prevents any personnel from
entering the area within one meter from the front of the antenna

• During antenna installation, be sure that power to the Tracer
equipment is turned off in order to prevent any energy presence
on the coaxial connector.

• During installation and alignment of the antenna, do not stand in
front of the antenna assembly.

• During installation and alignment of the antenna, do not handle
or touch the front of the antenna.

6/18/98

These simple precautions must be taken to prevent general population
and installation personnel from exposure to RF energy in excess of
specified MPE levels.

PAGE IV 61280.003L1-1B

6/18/98

61280.003L1-1B PAGE V
INSTALLATION

CONTENTS

PAGE

SECTION 1TRACER DESCRIPTION ..................................................... 1

INTRODUCTION .............................................................. 1

ISM BAND SPREAD SPECTRUM ................................... 1

APPLICATIONS ...............................................................2

SPREAD SPECTRUM ........................................................2

Direct Sequence ........................................................... 3

Coding .......................................................................... 3

CHANNEL SELECTION.................................................3

FORWARD ERROR CORRECTION ....................................4

T1 OPERATION ....................................................... 4

Framing ........................................................................ 4

Line Code ..................................................................... 4

DS1/DSX-1 Interface .................................................... 5

Line Buildout or LBO.................................................... 5

TRACER SYSTEM CONFIGURATION ..................................6

Baseband Processor or BBP........................................ 6

DS1/DSX-1 Interface .................................................... 6

VT-100 RS-232 Interface ............................................. 8

Alarm Contacts ............................................................. 8

IF Signal ....................................................................... 8

AC/DC Power................................................................ 9

Controls and Indicators ............................................... 9

Radio Frequency Convertor or RFC ........................... 11

Antenna ......................................................................13

SECTION 2INSTALLATION ..............................................................15

UNPACK, INSPECT ........................................................15

RACK-MOUNTED RFC CONFIGURATION .........................15

MAST-MOUNTED RFC CONFIGURATION .........................15

INSTALLATION ..............................................................16

LOCATION ............................................................16

POWER REQUIREMENTS ........................................... 16

GROUNDING ......................................................... 16

DS1/DSX-1 INTERFACE ........................................ 18

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PAGE VI 61280.003L1-1B

LINK PLANNING ...........................................................19

ANTENNA FEEDLINE LOSS ......................................... 20

ANTENNA GAIN ......................................................20

PATH LOSS ..........................................................21

PATH AVAILABILITY .................................................21

SETTING THE TRANSMITTER POWER ...................................22

SETTING THE RFC FREQUENCY PLAN ................................23

CONNECTING THE BBP AND THE RFC .............................. 24

APPLYING POWER ........................................................25

SETTING THE BBP FREQUENCY PLAN ................................ 25

SPREADING CODE ........................................................25

CO-LOCATING MULTIPLE 2.4 GHZ SYSTEMS .......................25

ANTENNA ALIGNMENT .................................................... 26

RF LOW ...................................................................27

REMOTE BERT ..........................................................27

ALARM CONTACTS ........................................................27

SECTION 3OPERATION ................................................................29

VT-100 USER INTERFACE .............................................29

RS-232 INTERFACE .................................................... 29

CABLE CONNECTIONS ....................................................29

PASSWORD ................................................................30

MAIN MENU SELECTIONS ............................................... 31

SYSTEM STATUS PAGE .............................................31

MAIN MENU PAGE ................................................. 32

T1 STATUS PAGE .................................................. 32

CHANNEL A STATISTICS PAGE ....................................33

CHANNEL B STATISTICS PAGE ....................................33

ALARM PAGE ........................................................34

TEST MENU .........................................................34

CONFIGURATION MENU ............................................35

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61280.003L1-1B PAGE VII

SECTION 4TROUBLESHOOTING .......................................................37

GENERAL .................................................................. 37

PROBLEM DESCRIPTIONS AND RECOMMENDED ACTIONS ........... 38

TROUBLESHOOTING USING THE FRONT PANEL INDICATORS .....38

“Link Error” light is lit, or link is down...................... 38

“BPV” light on T1-A or B is lit ....................................39

RED light on T1-A or B is lit .......................................39

“LBK-A” or “LBK-B” is lit ............................................ 40

“AIS/YEL” on T1-A or T1-B is lit.................................. 40

“AIS/YEL” indicator is flashing................................... 41

No “Power” light......................................................... 41

“Test” light is lit or blinking ....................................... 42

“TST” light is lit after pressing “Remote Test button .42
“Fail” light is lit after pressing “Remote Test” button 43

“RF Low” light is on ...................................................43

TROUBLESHOOTING USING THE VT-100 USER INTERFACE..44

RED Alarm ..................................................................44

BLV Alarm................................................................... 44

YEL/AIS Alarm ............................................................ 45

RF Link Alarm or Code Sync Alarm ............................ 46

Carrier Sync Alarm or T1 Mux Framer Alarm ............ 47

ES Values in T1 Status Menu...................................... 48

SES Values in History Menu .......................................48

SECTION 5SPECIFICATIONS ........................................................... 49

TRANSMITTER .............................................................49

RECEIVER ..................................................................49

FREQUENCY PLANS .......................................................49

SPREAD SPECTRUM DATA PUMP ......................................49

INTERFACE SPECIFICATIONS ............................................. 50

USER INTERFACE ......................................................... 50

VT-100 TERMINAL INTERFACE ........................................50

MECHANICAL & ENVIRONMENTAL .......................................50

POWER.....................................................................51

SECTION 6WARRANTY, ORDERING AND RETURN INFORMATION .................53

WARRANTY ................................................................53

SALES ......................................................................53

REPAIRS AND RETURNS ................................................. 53

TECHNICAL SUPPORT .................................................... 54

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PAGE VIII 61280.003L1-1B

GLOSSARY .............................................................................55

ACRONYMS USED IN THIS MANUAL .................................... 55

APPENDIX ACABLE CONNECTIONS ................................................... A-1

TERMINAL CONNECTION (DB25).................................... A-1

PERSONAL COMPUTER CONNECTION (DB9) ....................... A-1

MODEM CONNECTION (DB25) ...................................... A-2

APPENDIX B FCC REGULATIONS .....................................................B-1

AFFIDAVIT FOR CONNECTION OF CUSTOMER PREMISES
EQUIPMENT TO 1.544 MBPS AND/OR SUBRATE

DIGITAL SERVICES.......................................................B-3

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61280.003L1-1B PAGE IX

ILLUSTRATIONS

1-1. Typical Application ......................................... 2

1-2. Bandwidth Division ........................................3

1-3. BBP................................................................ 6

1-4. BBP Rear Panel .............................................6

1-5. BBP Block Diagram ....................................... 7

1-6. BBP Front Panel (with door closed) .............. 9

1-7. BBP Front Panel (with door open)................. 9

1-8. RFC Module.................................................. 11

1-9. RFC Function Block Diagram ....................... 12

1-10.Mast-Mount RFC Housing .............................13

1-11.Rack-Mount RFC Housing ............................13

2-1. Diplexer .......................................................23

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3-1. System Status Page......................................31

3-2. Main Menu Page ..........................................32

3-3. T1 Status Page............................................. 32

3-4. Channel A Statistics Page ............................33

3-5. Channel B Statistics Page ............................33

3-6. Alarm Page ..................................................34

3-7. Test Menu.....................................................34

3-8 T1 Loopback Locations ................................35

3-9. Configuration Menu .....................................35

PAGE X 61280.003L1-1B

6/18/98

61280.003L1-1B PAGE 1

SECTION 1 TRACER DESCRIPTION

INTRODUCTION

The Tracer provides dual T1 transport by way of a spread spectrum
microwave link for distances up to 20 miles or more depending
on path engineering. System performance is determined, in part,
by the engineering of the microwave link. Each end of a Tracer
link is composed of two units -- the baseband processor (BBP)
and the radio frequency converter (RFC). Two DS1/DSX-1 (T1)
interfaces are provided on the rear of the BBP, which can be
mounted in a 19" rack. The DS1/DSX-1 interface provides
connections up to 6000 feet from T1 equipment. A single coaxial
cable connects the BBP to the RFC and another connects the RFC
to the antenna.

ISM BAND SPREAD SPECTRUM

The Federal Communications Commission (FCC) has established
several portions of the radio frequency (RF) spectrum for use in
Industrial, Scientific, and Medical (ISM) applications. Part 15.247
of the FCC rules describes the requirements of systems that operate
in these bands. The three bands set aside, 902-928 MHz,
2400-2483.5 MHz, and 5725-5850 MHz, are designated for use
by spread spectrum transmitters, either frequency hopping or
direct sequence. The Tracer operates in the 2400 to 2483.5 MHz
band using direct sequence spread spectrum (DSSS) transmission.

4/12/99

PAGE 2 61280.003L1-1B
SECTION 1

APPLICATIONS

Any application that would typically use metallic T1 as a transport
can use the Tracer instead. The figure below illustrates a typical
application.

Antenna Antenna

RF Cable

Mast Unit

TRACER
Baseband Processor

VT-100

RS-232

Terminal

Switch

2xT1, Mast-mounted RFC

IF Cable

TRACER

T1A

T1B

TRANSCEIVER

BPV

BPV

POWER

AIS

AIS

DATA LOSS

DATA LOSS

T1
T1

MSC

RF Cable

TRACER
Baseband Processor

TRACER

T1A

T1B

TRANSCEIVER

BPV

BPV

POWER

AIS

AIS

DATA LOSS

DATA LOSS

TRACER

T1
T1

Cell Radio

Cellular/PCS Site

2xT1, Rack-mounted RFC

Rack-mount RFC

Mast and Rack mount RFCs may be mixed to accommodate individual system requirements.

Figure 1-1. Typical Application

The Tracer can be used in any application requiring that data be
shared at a high rate of speed. In addition to telephony
applications, Tracer can be used in data communications such as
inter-networking, video conferencing, and telemetry.

SPREAD SPECTRUM

Spread spectrum is a form of communication in which the
bandwidth of a message signal is intentionally increased or
“spread.” The FCC rules allow two methods of spreading -­frequency hopping and direct sequence. Tracer employs direct
sequence spread spectrum.

4/12/99

61280.003L1-1B PAGE 3
TRACER DESCRIPTION

DIRECT SEQUENCE

A direct sequence transmitter spreads the signal by mixing the
data with the output of a pseudorandom number generator which
changes state at a rate higher than the data rate. This rate is called
the “chipping” rate. The Tracer chipping rate is twelve times the
data rate.

CODING

Many different pseudorandom sequences exist. The sequences
are called pseudorandom because, although they appear noise­like, they are determinant and repeat after a specific number of
chips. The longer a code is, the better correlation characteristics
it possesses. These traits allow multiple spread spectrum systems
to operate in the presence of one another with minimal interference
if they are operating with different sequences. The Tracer allows
the selection of one of ten different 120-bit long sequences.

CHANNEL SELECTION

4/12/99

The FCC has allocated 83.5 MHz of spectrum in the band in which
the Tracer operates. A Tracer system fully uses the available
bandwidth -- transmitting in one half and receiving in the other.
The figure below illustrates the bandwidth division.

2400 MHz

2441 MHz

2483.5 MHz

Figure 1-2. Bandwidth Division

PAGE 4 61280.003L1-1B
SECTION 1

The transmitter at one end (TxA) of a link will transmit in the
lower half of the spectrum. Consequently the receiver at the other
end will receive in the lower half of the band and transmit in the
upper half. Thus, a system will operate in one of two frequency
plans -- transmit in the upper and receive in the lower or vice
versa. These two plans are called Plan A and Plan B. One end of
a path will be on Plan A and the other will be on Plan B. Shipment
of a link will consist of an A and a B unless specified otherwise.

FORWARD ERROR CORRECTION

With the addition of overhead data, error detection and correction
capability can be added to a data stream. Error correction can be
accomplished by allowing the receiver to request the re­transmission of an errored block once detected. The Tracer, on
the other hand, implements forward error correction (FEC) which
adds enough overhead data for the receiver to detect and correct
errors in the data stream. This capability comes at the cost of
bandwidth. The addition of FEC decreases the required signal­to-noise (S/N) ratio by approximately 5.5␣ dB to achieve a given
bit error rate (BER).

T1 OPERATION

FRAMING

The data in a T1 stream is delimited by framing bits. The pattern
of the framing bits follows one of two formats -- extended
superframe (ESF) or superframe (SF). The T1 interface must be
prepared for the format that will be used.

LINE CODE

A mark in the data stream is coded as a pulse on the T1 line. A
space is coded as “no activity” on the T1 line. As a form of error
detection, subsequent marks in the data stream are coded as pulses
of alternating polarity, either positive going or negative going. This
type of line coding is called alternate mark inversion (AMI).

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61280.003L1-1B PAGE 5
TRACER DESCRIPTION

For the T1 receiver to operate correctly, a minimum number of
“1s” must exist on the T1 facility. If the data cannot be guaranteed
to meet this requirement, then another line coding format is used.
In the bipolar 8 zero substitution (B8ZS) scheme, a string of eight
“0s” is replaced by a special sequence of eight bits that contains a
bipolar violation. The receiver, upon recognizing this sequence,
reinserts the eight “0s” and the data is recovered intact.

DS1/DSX-1 INTERFACE

When connecting the interface to the public switched network,
an ADTRAN-provided cross-over cable (part number

3125.M011@A) is required to meet FCC part 68 and IC CS03
requirements. This cable is required to cross-over the Tx and Rx
pairs to meet the connecting arrangement of a network interface
device. This cable is included with the BBP and is labelled “T1
Crossover.”

LINE BUILDOUT OR LBO

4/12/99

The DS1/DSX-1 interface provides two different types of line
buildouts (LBOs), respectively. When set for DS1, LBOs for 0␣ dB,

-7.5 dB, -15 dB, and -22 dB are available. The DS1 interface can
operate on line lengths up to 6,000 feet. When set for DSX-1
interface, LBOs for 0-133 feet, 266-399 feet, 399-533 feet, and
533-655 feet are available.

PAGE 6 61280.003L1-1B
SECTION 1

Tracer SYSTEM CONFIGURATION

A Tracer system is composed of three major subsystems -- a
baseband processor, a radio frequency convertor, and an antenna.
The following section describes the system components.

BASEBAND PROCESSOR OR BBP

The BBP (ADTRAN part number 1280.003L1) is a 1-U, 19" rack­mountable unit that provides the system electrical interfaces, user
controls and indicators, and performs the spread spectrum
processing for the system. The rear panel provides all of the
electrical interface points -- DS1/DSX-1 interface, DS1/DSX-1
monitor, VT-100 terminal, alarm contacts, IF signal, DC power
(from facility), and power (from AC adapter). The BBP and its
rear panel are illustrated in the figures below.

TRATRACERCER

Figure 1-3. BBP

Figure 1-4. BBP Rear Panel

DS1/DSX-1 INTERFACE

Two DS1/DSX-1 interfaces, labelled “T1A” and “T1B,” are provided
for connecting to the T1 equipment. Two types of physical
interfaces are provided -- RJ-48C and bantam jacks.

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61280.003L1-1B PAGE 7
TRACER DESCRIPTION

The interfaces are illustrated in the BBP Block Diagram below.
The functions of the BBP are partitioned into three printed circuit
boards or PCBs, all contained in the same enclosure.

Baseband Processor Board

RS-232

µCUART DSP

T1A

T1B

IF

-48Vdc

T1

T1

T1C

Multiplex

Fc = 140 MHz

Filter

Fc = 70 MHz

IF Interface Board

Viterbi

Encoder/

Decoder

Σ

Spread

Spectrum

Data

Pump

90

90

Figure 1-5. BBP Block Diagram

The DS1/DSX-1 interfaces provided for each channel are the same.
The upper bantam connectors, labeled “Monitor,” provide isolated
monitor points for testing. The lower bantam jacks provide signal
insertion points. The insertion of a bantam jack disconnects the
RJ-48C connector from the circuit. The DS1/DSX-1 interface can
operate on line lengths up to 6000 feet.

4/12/99

When connecting either T1 interface to the public switched
network, an ADTRAN-provided cross-over cable (part number

3125.M011@A) is required to meet FCC part 68 and IC CS03
requirements. This cable is included with the BBP and is labelled
“T1 Crossover.” This cable is required to cross-over the TX and
RX pairs to meet the connecting arrangement of a network interface
device.

PAGE 8 61280.003L1-1B
SECTION 1

For connections to other CPE-type equipment, such as an
ADTRAN TSU-100, a straight-through T1 cable is provided by
ADTRAN (part number 3127.004) and is included with the BBP.

VT-100 RS-232 INTERFACE

A serial interface port using RS-232C signal levels is provided for
attaching a VT-100-compatible terminal. The connection is made
via a DB-25 connector on the rear panel. The data rate is configured
for 9600 bps, 8 data bits, no parity, and 1 stop bit.

ALARM CONTACTS

Two sets of alarm contacts are provided on the rear of the BBP:
major alarm and minor alarm. A major alarm indicates the radio
link is not operational. A minor alarm indicates that system
performance is degraded or that the T1 interfaces are experiencing
errors. Normally-open and Normally-closed contacts are provided
for both alarm types. Under normal operating conditions there is
no continuity between the Normally-open and Common contacts,
and, under an alarm condition, continuity between those contacts
exists. The Normally-closed and Common contacts normally have
continuity, while under alarm conditions, these contacts are open.

IF SIGNAL

The N-type connector on the rear panel provides the interface
point between the BBP and the RFC. This connection provides
the data signal, power, and configuration information to the RFC.
A coaxial cable (ADTRAN part number 3125.001@A) is provided
for connecting the BBP to the RFC for the rack-mount model .
Cable for connecting the BBP to a mast-mount RFC must be
provided by the customer after the length of cable has been
determined.

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61280.003L1-1B PAGE 9
TRACER DESCRIPTION

AC/DC POWER

The unit receives power via one of two connectors. Power for the
entire system is provided by these interfaces. The three-pin circular
DIN connector is provided to connect an optional ADTRAN
desktop AC adapter (ADTRAN part number 1360.DSK24VL1),
providing 24 volts DC. The three-pin terminal block allows the
connection of any DC power source providing between 21 and 56
volts DC. The power consumption of the entire system is 30 watts.

CONTROLS AND INDICATORS

The system may be configured via the front panel, which is
accessible behind a drop-down panel on the right half of the BBP.
The front panel is illustrated in the figure below.

4/12/99

Figure 1-6. BBP Front Panel (with door closed)

Figure 1-7. BBP Front Panel (with door open)

Options that are set from the front panel can be overridden via
the terminal interface. As a rule, a green LED indicates a good
situation, a red LED indicates an error situation, and a yellow LED
indicates a configuration option. LEDs indicating overall system
integrity are listed below.

Test .............. Red indicates that the self-test has completed and

failed

PWR............. Green indicates that DC voltage is applied

PAGE 10 61280.003L1-1B

ECTION 1

S

The LEDs associated with the DS1/DSX-1 interfaces are listed
below. There are two sections of identical indicators -- one for
each DS1/DSX-1 interface.

BPV .............. Red if the incoming T1 stream contains bipolar

violations

RED ............. Red if there is no signal present at the T1 interface

LPBK ............ Yellow if the T1 interface is in loopback

YEL/AIS ....... Flashes to indicate a T1 Yellow Alarm; remains On

(solid) to indicate an AIS alarm (when the DS1/DSX-1

is receiving a Blue code)

The LEDs indicating error conditions are listed below.

RF Low ................ Red indicates the received RF carrier level is too

low

Link Down........... Radio path is down

The front panel pushbutton controls are listed below.

Reset .................... Reset the system

LBKA ................... Toggles the T1-A between no loopback and line

loopback

LBKB .................... Toggles the T1-B between no loopback and line

loopback

Plan Sel ................ Toggles between frequency plans A and B (must

match frequency plan cabling on RFC). Refer to
“Setting the RFC Frequency Plan” in Section 2 of
this manual.

Remote Test ......... Initiate a remote test across the RF link

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61280.003L1-1B PAGE 11

R

X

T

X

I

F

RSSI

GND

TX-PWR

TRACER DESCRIPTION

The monitor points provided on the front panel of the system are
listed below

I............................ Demodulated received baseband output

Q .......................... Demodulated received baseband output

CLK ..................... Recovered clock for observing EYE pattern

RSSI ..................... DC voltage indicating strength of the received

signal at the antenna

+5 ......................... System 5 volts

-5.......................... System -5 volts

+12 ....................... System +12 volts

-12........................ System -12 volts

RF PWR ............... Voltage supplying RF power

GND .................... System ground

RADIO FREQUENCY CONVERTER OR RFC

The radio frequency converter or RFC (ADTRAN part number

1280.005L1) provides the RF interface between the BBP and the
antenna.

The RFC module is illustrated in the figure below.

Figure 1-8. RFC Module

The RFC is partitioned, functionally, into two major components

-- the transmitter and the receiver. It is partitioned physically into
three printed circuit boards.

The major connections illustrated are the transmit signal, receive
signal, and the IF signal connection.

The three SMA connectors located on the RFC module provide
the transmitted RF, received RF, and IF connection points. Two
test points are provided for monitoring the received signal strength

4/12/99

indicator or RSSI. The voltage (relative to the GND test point)
present on this test point represents the level of the received signal.

PAGE 12 61280.003L1-1B
SECTION 1

This signal is used to align the antenna during installation and to
verify that the link is performing as designed. A third test point is
provided to monitor the transmitter output power during system
configuration.

The only connections that must be made in the field are a coax
connection between the BBP and the RFC and a coax connection
between the RFC and the antenna.

The “IF” connector provides the connection between the BBP and
the rack or mast-mounted RFC. (A blue 6-inch IF cable [ADTRAN
part number 3125.001@A] is provided for rack-mount systems.
ADTRAN does not provide IF cable for mast-mount systems.) The
“ANTENNA” connector provides the connection between the RFC
and the antenna.

A block diagram of the RFC functions is shown in the figure below.

Rx

Tx

SAW

2018

2018
2058

2058

PA

2321
2281

LPF

333

RF2

Splitter

AGC

IF

Splitter

AGC

Figure 1-9. RFC Function Block Diagram

The RFC unit is enclosed in a metal housing measuring
approximately 10.5" x 5.5" x 1" and may be mounted in a 1-U
nineteen-inch rack space or in a weather-tight enclosure suitable

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61280.003L1-1B PAGE 13
T

RACER DESCRIPTION

for mast-mounting near the antenna for enhanced system
performance. The RFC mast-mount and rack-mount housings
are illustrated below.

WARNING

Housing Assembly and Guide

Mounting Clearances

for Mounting Bracket

Holes

Figure 1-10. Mast-Mount RFC Housing

TRATRACERCER

Figure 1-11. Rack-Mount RFC Housing

4/12/99

ANTENNA

Tracer is intended to be coupled with an antenna that is directional
and provides signal gain. There are several reasons for this
requirement:

• Tracer operates in point-to-point applications; therefore, an
omnidirectional antenna is not needed.

• The FCC provides no recourse in this band in the event of nearby
interference, so a highly directional antenna reduces the
likelihood of interference in the antenna pattern.

• The low power transmitter is intended to be used with a high­gain antenna for long links.

The antenna requirements are listed below.

Minimum gain .................... 15 dBi

Minimum return loss .......... 15 dB

Connector ........................... N-type

Impedance ........................... 50Ω