Valcom v-9939a Service Manual

V-9939A

MICROPHONE ADAPTOR

INTRODUCTION

These instructions provide identification, installation,
connection, operation, and maintenance information
for the V-9939A, Microphone Adaptor.

The V-9939A is a Microphone Adaptor designed to
be used with Valco m paging equipment.

SPECIFICATIONS

Purpose

• Provides microphone access to Valcom one-way

amplified speaker assemblies.

Applications

• Allows local paging access to a zone of one-way

paging speakers.

• Allows paging access to stand alone systems.

Refer to Figure 1 for a block diagram of a typical
installation.

Features

• 600 ohms balanced and 50,000 ohm inputs

• Works with most microphones with push to talk

switches

• Built in microphone preamplifier

• Mounts at microphone location

• Provides a set of form "C" contacts

• May be connected to a selected zone of a multi-

zone paging system

• Screw terminals for all connections

Capacity

Each V-9939A may be connected to one zone of a
paging system.

Dimensions/Weight

• 7.1”H x 4.7”W x 2.1"D

(18.03 cm H x 11.94 cm W x 5.33 cm D)

0.7lbs. (32kg)

VSP-V-9939A

Issue 8

Power Requirements

–21.5 to –26 Vdc filtered "A" Battery, 40 ma. max

Environment

Temperature: 0 to 50 Degrees C
Humidity: 0 to 85% non-precipitating

Nominal Specifications

Input impedance 600 ohms balanced/

50,000 ohms unbalanced
Output impedance 600 ohms
Output level -10dbm nominal

SYSTEM DESIGN

Configuration

There are two basic ways the V-9939A Microphone
adaptor may be used:

1. It may be used with a V-1094A and Valcom

one-way amplified speaker assemblies as a
stand alone paging system.

When using the V-9939A for access to a stand alone
paging system, the following will be required:

• 1 V-9939A Microphone Adaptor

• 1-Microphone (push to talk)

• 1 V-1094A Booster Control

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• Valcom one-way amplified speaker assemblies

(type determined by job requirements)

• Power Supply (type determined by style and

quantity of speakers - Consult the Valcom
One-Way Paging VSP for more information)

Microphone Requirements

A standard high impedance (50,000 ohms) or low
impedance balanced (600 ohms) microphone may be
used. The microphone will be required to provide a
dry contact closure (push to talk) for page access.

2. By using the V-9939A with a V-1101A One
Zone One-way Page Adaptor or a V-9937
One Zone Page Port Adaptor you may
automatically disconnect the speakers of one
zone from a multi-zone page adaptor and
allow microphone access to that zone.
These configurations will allow the
microphone to override the telephone
access.

NOTE: These will work only on a zone of
ONE-WAY pagi ng.

Amplified Speakers

V-9939A V-1094A

Power
Supply

Figure 1 - Block Diagram of a Typical Installation

When using the V-9939A to override an existing zone
of telephone accessed one-way paging, the following
will be required:

• 1 V-9939A Microphone Adaptor

• 1-Microphone (push to talk)

• 1 V-1101A One Zone Page Adaptor

OR

• 1 V-9937 One Zone Page Port Adaptor

• An existing Valcom one-way page system

Other configurations are possible. Contact Technical
Support {[phone]} with questions on specific
applications.

INSTALLATION

These instructions cover the installation procedures
for the Valcom V-9939A and any associated Valcom
equipment. Please consult practices for other
manufacturer's equipment if any other equipment is
being used. Refer to Figure 2 for location of sc rew
connections. Refer to Figure 3 for screw connection
designations.

The following sections contain step-by-step
instructions for wiring the V-9939A and associated
Valcom equipment. Each instruction is preceded by a
line. Place a check on the appropriate line as the
instruction is completed. The instructions also
include tests along the way to verify connections have
been made correctly. If these steps are followed
exactly, installation of your Valcom system will go
smoothly and quickly. If the results of a test do not
correspond with what is shown, DO NOT PROCEED
UNTIL THE PROBLEM HAS BEEN
CORRECTED.

NOTE: During initial system setup it is
recommended that all volume controls be set 1/2 turn
clockwise.

Mounting

• Using two #6 3/4" wood screws, mount the unit

in a convenient location near the microphone
location

NOTE: DO NOT locate the V-9939A closer than
18" to a power supply or any equipment that
generates electrical noise.

Power Connections

___ 1. Unplug power supply.
___ 2. Connect –24 Vdc "A" battery (may be

referred to as "-" or "talk battery") from
power supply to one of the PWR terminals
on the V-9939A.

___3. Connect –24 Vdc Ground ("A" ground,

"+" or "talk" ground) from power supply to
the other power terminal. This GND should
be properly grounded to an earth gro und to
alleviate hum on the system.

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Connecting Arrangements

NOTE: Place a check by the Arrangement being used
and proceed to the Figure indicated for step-by-step
instructions.

___1. Stand alone page system: Proceed to Figure

4.

___2. Override an individual zone using a

V-1101A: Proceed to Figure 5.

___3. Override an individual zone using a V-9937:

Proceed to Figure 6.

Volume
Control

V-9939A

Figure 2 - Location of Screw
and Volume

PWR MC HZ B S RING

PWR LZ1SW GND

LZ2

Figure 3 - Screw Connection

Designations

MTIP

OUT

WIRING INSTRUCTIONS

(For Figure 4)

Place a check by each step as it is completed:

___1. Mount the V-1094A near the V-9939A or at

the main frame.

___2. Connect Tip of the V-9939A to Tip of the

V-1094A input.

___3. Connect Ring of the V-9939A to Ring of

the V-1094A input.

___4. Connect Tip of the V-1094A output to the

Tip side of all the one-way amplified
speaker assemblies.

___5. Connect Ring of the V-1094A output to the

Ring side of all the speakers.

___6. Connect the microphone:

___a. Connect the audio common lead shield

from the microphone to the MC terminal
of the V-9939A. (This shield should be
strapped to power supply GND).

___b. Connect the other microphone audio lead

to HZ if using a high impedance
microphone; if using a low impedance
balanced microphone, connect (+) lead to
LZ1, and the (-) lead to LZ2.

___c. Connect one side of the microphone push

to talk switch to switch to the V-9939A
SW terminal.

___d. Connect the other side of the push to talk

switch to the GND OUT terminal.

___7. Connect –24 Vdc from the power supply to

the –24 Vdc terminal of the V-1094A.

___8. Connect Ground (+) of the power supply to

the Ground terminal of the V-1094A.

___9. Connect –24 Vdc from the power supply to

the –24 Vdc terminal (or the white lead) of
each speaker assembly.

___10. Connect Ground of the power supply to the

Ground terminal (or the black lead) of each

speaker assembly.
___11. Plug in the power supply.
___12. Volume adjustment:

___ a. Set the V-1094A volume control to 5.
___ b. Turn the screwdriver adjustable volume

control on the V-9939A about 1/2 of the

way clockwise.
___ c. Verify all speaker controls are set at 1/2.
___ d. Speak through the microphone and adjust

the V-1094A for the proper system level.
___ e. Speak through the microphone and adjust

the individual speakers to the required

levels.

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MICROPHONE

SWITCH

AUDIO

GND STRAP

V-9939A V-1094A

PWR MC HZ RING

PWR LZ1 SW GND

LZ2

AB AG BB BG

-24VDC POWER SUPPLY

MICROPHONE

SWITCH

AUDIO

GND STRAP

V-9939A

PWR MC HZ RING

PWR LZ1 SW GND

BS

MTIP

OUT

R IN -24 R OUT

T OUTT IN

GND

FIGURE 4 - STAND ALONE PAGE SYSTEM

V-1101A

WH/BL
BL/WH
WH/OR
WH/GN

RD/GN
GN/RD
RD/BN

B

OUT

BN/RD

S

MTIP

VI/BN
BN/VI
VI/SL
SL/VI

ONE-WAY
AMPLIFIED
SPEAKER
ASSEMBLIES

TO ONE ZONE
OF A PAGE
CONTROL UNIT

ONE-WAY
AMPLIFIED
SPEAKER
ASSEMBLIES

LZ2

AB AG BB BG

-24VDC POWER SUPPLY

FIGURE 5 - OVERRIDE A SINGLE ZONE WITH A V-1101A

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WIRING INSTRUCTIONS

Place a check by each step as it is completed:

___ 1. IMPORTANT: Complete installation and

testing of your page control unit and
speakers before adding the microphone
adaptor.

___ 2. Mount the V-1101A near the microphone

adaptor and connect it to a terminated 25
pair cable.

___ 3. Connect Tip of the V-9939A to Tip

(white/blue) of the V-1101A.

___ 4. Connect Ring of the V-9939A to Ring

(blue/white) of the V-1101A.

___ 5. Add a jumper on the V-1101A between the

white/orange and the white/green.

___ 6. Connect the white/orange of the V-1101A to

terminal S on the microphone adaptor.

___ 7. Connect the violet/slate of the V-1101A to

terminal M of the microphone adaptor.

___ 8. Disconnect Tip of the audio pair to the

speakers on the zone being overridden from
the Page Control unit and connect it to the
red/brown of the V-1101A.

___ 9. Disconnect Ring of the audio pair to the

speakers from the Page Control unit and
connect it to the brown/red of the V-1101A.

___10. Connect the red/green of the V-1101A to

one side of the output pair from the page
control unit for the zone to be overridden.

___11. Connect the green/red of the V-1101A to the

other side of the output pair from the page
unit for the zone being used.

___12. Connect the microphone:

___a. Connect the audio common lead shield of

the microphone to the MC terminal of the
V-9939A. This shield should be strapped
to power supply GND.

___b. Connect the other microphone audio lead

to HZ if using high impedance
microphone; if using a low impedance
balanced microphone, connect (+) lead to
LZ1 and the (-) lead to LZ2.

___c. Connect one side of the microphone push

to talk switch to the V-9939A SW
terminal.

___d. Connect the other side of the push to talk

switch to the GND OUT terminal.

___13. Connect –24 Vdc filtered talk battery from

the power supply to the brown/violet of the
V-1101A.

___14. Connect Ground (+) of the power supply to

the violet/brown of the V-1101A.

___15. Connect –24 Vdc signal battery from the

power supply to the slate/violet of the
V-1101A.

(For Figure 5)

___16. Connect signal ground of the power supply

to the violet/slate of the V-1101A.

___17. Power Test

___a. Plug in the power supply.
___b. Momentarily short between the white/slate

and slate/white of the V-1101A. If you

hear a relay activate, then go to step 18.
___c. If you do not hear a relay, then unplug the

power supply and go back to steps 13 to

16 and veri fy your connections.

___18. Volume adjustment:

___a. Turn the screwdriver adjustable volume

control on the V-9939A about 1/2 of the

way clockwise.
___b. Speak through the microphone and adjust

the V-9939A screwdriver adjustment for

the proper page level.

WIRING INSTRUCTIONS

Place a check by each step as it is completed:

___ 1. IMPORTANT: Complete installation and

testing of your page control unit and
speakers before adding the microphone
adaptor.

___ 2. Mount the V-9937 near the microphone

adaptor.

___ 3. Connect Tip of the V-9939A to pin 2 of the

V-9937.

___ 4. Connect Ring of the V-9939A to pin 17 of

the V-9937.

___ 5. Connect terminal S of the V-9939A to pin 3

of the V-9937.

___ 6. Connect terminal M of the V-9939A to pin

18 of the V-9937.

___ 7. Disconnect Tip of the audio pair to the

speakers on the zone being overridden from
the Page Control unit and connect it to pin 7
of the V-9937.

___ 8. Disconnect Ring of the audio pair to the

speakers from the Page Control Unit and
connect it to pin 22 of the V-9937.

___ 9. Connect pin 4 of the V-9937 to one side of

the output pair from the page control unit
for the zone being overridden.

___10. Connect pin 19 of the V-9937 to the other

side of the output pair from the page control
unit for the zo ne being overr idden.

___11. Connect the microphone:

___a. Connect the audio common lead shield of

the microphone to the MC terminal of the

V-9939A. This shield should be strapped

to power supply GND.
___b. Connect the other microphone audio lead

to HZ if using a high impedance

(For Figure 6)

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microphone: if using a low impedance
balanced
microphone, connect (+) lead to LZ1 and
the (-) lead to LZ2.

___c. Connect one side of the microphone push

to talk switch to the V-9939A SW
terminal.

___d. Connect the other side of the push to talk

switch to the GND OUT terminal.

___12. Connect –24 Vdc (BB) signal battery from

the power supply to pin 30 of the V-9937.

___13. Connect signal ground (BG) of the power

supply to pin 29 of the V-9937.

___14. Volume adjustment:

___a. During initial system set up, set the

screwdriver adjustable volume control on

the V-9939A 1/2 turn clockwise.
___b. Speak through the microphone and adjust

the screwdriver adjustable volume

controls on the V-9939A and output 1 of

the V-9937 to the desired page level.
___c. Access zone through the telephone

system; adjust input 3 volume control on

the V-9937 for the desired page level.

TO A ZONE OF A
PAGE CONTROL
UNIT

MICROPHONE

SWITCH
AUDIO

GND STRAP

PWR MC HZ RING

PWR LZ1 SW GND

LZ2

AB AG BB BG

-24VDC POWER SUPPLY

-24 OUT

TIP OUT 2

TIP OUT 1

GROUND OUT

GROUND OUT

RING OUT 1

SINGLE TONE

WARBLE TONE

SINGLE TONE

RING OUT 2

WARBLE TONE

GND OUT

-24 OUT

30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

-24VDC IN

GROUND IN

V-9939A

S

B

MTIP

OUT

FIGURE 6 - OVERRIDE A SINGLE ZONE WITH A V-9937

-24 OUT

IP INPUT 3

CONTROL GND IN

CONTROL GND OUT

RING INPUT 2

RING INPUT 3

ONE-WAY
AMPLIFIED
SPEAKER
ASSEMBLIES

TIP INPUT 2

TIP INPUT 1

123456789101112131415

RING INPUT 1

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OPERATION

Circuit Description

The V-9939A Microphone Adaptor has inputs for
both high impedance and balanced low impedance
microphones. It also has an input for a push to talk
contact closure. When the closure is applied, a high
gain pre-amplifier is turned on and the output relay is
activated. The unit will stay active until the contact
closure is removed. The preamplifier circuit also
contains a voice limiting circuit to limit extremely
loud inputs.

TECHNICAL ASSISTANCE

When trouble is reported, verify that power is being
supplied to the unit and there are no broken
connections. Check voltages for proper polarity on
the crossconnect block.

Table 1 identifies symptoms of some possible
problems with solutions. If a spare unit is available,
continue to troubleshoot by substituting the spare unit
for the suspected defective unit.

Assistance in troubleshooting is available from the
factory. When calling, you should have a VOM and a
test set available and be calling from the job site.
Call [phone] and ask for Technical Support,
or call [phone] for Valcom 24-hour
Automated Support or visit our website at
http://www.valcom.com.

The V-9939A is not field repairable. Valcom

equipment contains no user serviceable parts
inside. Valcom, Inc. maintains service facilities in

Roanoke, VA. Should repairs be necessary, attach a
tag to the unit clearly stating your company name,
address, phone number, and contact person; and the
nature of the problem.
Send the unit to:

Valcom, Inc.

Repair and Return Dept.

5614 Hollins Road

Roanoke, VA 24019-5056

TABLE 1 - TROUBLESHOOTING CHART

SYMPTOM

1. No relay operation in V-9939A
when microphone talk button is
pressed.

2. Relay operation but no output.

3. Audio from V-9939A but not
from V-1094A.

4. No output from V-1101A.

5. Output from V-9939A and
V-1094A or V-1101A but not
from speakers.

SOLUTION

Check for –24 VDC at V-9939A across the PWR terminals. Verify
connection from microphone to terminals SW and GND OUT (refer to
the Installation section).

Verify connections from microphone to MC and HZ or LZ terminals.
Turn volume control up (cloc kwise) .

Verify Tip and Ring connections from V-9939A to V-1094A. Verify
proper voltage and polarity at –24 VDC and GND terminals of
V-1094A. Turn up volume at V-1094A.

Recheck all connections per Figure 5. Make sure the V-1101A passes
the power test in Figure 5, step 17.

Verify proper voltage and polarity to speakers. Verify audio
connections to speakers. Verify speakers are Valcom one-way amplified
speaker assemblies.

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INPUTS

HZ
LZ1
LZ2
MC

AMPLIFIER AND
VOLUME CONTROL

TRANSFORMER TRANSFORMER

OUTPUTS

TIP

RING

SW

GND OUT

PWR
PWR

CONTROL
CIRCUITRY

RELAY

MAKE
STATIONARY
BREAK

V-9939A SIMPLIFIED SCHEMATIC

VALCOM LIMITED WARRANTY

Valcom, Inc. warrants its products to be free from defects in materials and w orkmanship under conditions of normal use and service
for a period of one year from the date of shipment. The obligation under this warranty shall be limited to the replacement, repair or
refund of any such defective device within the warranty period, provided that:

1. inspection by Valcom, Inc. indicates the validity of the claim,

2. the defect is not the result of damage, misuse, or negligence after the original shipment.

3. the product has not been altered in any way or repaired by others and that factory sealed unit s are unopened (A service

4. freight charges for the return of products to Valcom are prepaid,

5. all units ‘out of warranty’ are subject to a service charge. The service charge will cover minor repairs (Major repairs will be

charge plus parts and labor will be applied to units defaced or phy sically damaged),

subject to additional charges for parts and labor).

This warranty is i n lieu of and excludes all other warranties, expressed or implied, and in no event shall Valcom, Inc. be
liable for any anticipated profits, consequential damages, loss of time or other losses incurred by the buyer in connection
with the purchase, operation, or use of the product.

This warranty specifically excludes damage incurred in shipment. In the event a product is received in damaged condition, the
carrier should be notified immediately. Claims for such damage should be filed with the carrier involved in accordance with the
F.O.B. point.

Headquarters: In Canada

Valcom, Inc. CMX Corporation

1111 Industry Avenue 35 Van Kirk Drive #11 and 12

Roanoke, VA 24013 Brampton, Ontario L7A1A5

Phone: [phone] Phone: [phone]

FAX: [phone] FAX: [phone]

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