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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