2
Dimensions/Weight
8.25" H x 4.65" W x 2.30" D
(20.96cm H x 11.81cm W x 5.84cm D)
1.5 lbs. (0.68 kg)
Power Requirements
21.5 to -26VDC "B" Battery, 300mA maximum
Environment
Temperature:
0 to +50° C
Humidity:
0 to 85% (non-precipitating)
SYSTEM DESIGN
General
The Valcom V-9941A talkback control unit is
designed to provide paging access from a C. O.
position or loop start trunk port of a telephone
system. The V-9941A may also be connected to a
600 Ohm two-way page port with a contact closure or
a dedicated single line telephone. The V-9941A
contains all the VOX and handsfree amplifier
circuitry required to drive up to two Valcom 45 Ohm
talkback speakers.
Electronic Key, PABX Access or
Dedicated Single Line Telephone
The following components are required when paging
from a PABX loop start trunk port, Electronic Key
System C. O. line position or a Dedicated Single Line
Telephone:
A telephone system C. O. line port or PABX loop
start trunk port with a circuit card installed or a
dedicated single line telephone:
(1) V-9941A talkback control unit
(1) VP-624B power supply
45 Ohm talkback speakers (maximum two)
Page Port Access (600 Ohms) with
Contact Closure
The following components are required when paging
from a 600 Ohm two-way paging port:
600 Ohm two-way paging port with contact closure
(1) V-9941A talkback page control
(1) VP-624B power supply
45 Ohm talkback speaker (maximum two)
Background Music
The V-9941A provides background music input and
is designed to automatically cut off the music during
a page. If background music is to be installed, a
receiver providing an 8 Ohm output with 1-3 Watts of
output power will be required.
Inhibit Option
The V-9941A is equipped with an inhibit lead that
may be used in special applications to automatically
turn off the speakers and allow a handset
conversation between the calling party and a single
line telephone connected to the paging Tip and Ring.
To use the inhibit function you will need a dedicated
single line telephone modified for "A" Lead Control
and a 5.1K Ohm 1/4 Watt resistor.
INSTALLATION
Mounting
Remove the metal mounting plate from the rear of the
V-9941A enclosure. Using two #6 ¾ inch wood
screws, mount the plate in a vacant space on the
backboard with the telephone system common
equipment.
Both mounting holes must be utilized
to insure secure mounting of the unit.
See Figure 1A.
Open the V-9941A enclosure to access connections
and option switches. Slide the rear of the unit
(contains the board) onto the mounting plate and lock
in place with screw provided. Make connections.
Replace cover and lock in place with the #6 ¾ inch
screw provided.
C. O. Line
Position or
Loop Start
Trunk Port
Electronic Key
or PABX
V-9941A
Power
Supply
Talkback
Speaker
Figure 1 - Typical Loop Start Trunk Installation
