Operation; Circuit Description - Valcom V-119RTHF Instruction Manual

__ 2. Strap A ground, B ground and lamp ground
common at power supply.
__ 3. Refer to Figure 1 for connecting block
layout and connections.
Limit cable runs to talkback speakers to not more
than 800 feet. Do not split pairs.
Limit audio runs to one-way amplified speakers to
not more than 5000 feet. Limit power runs to
one-way speakers to maximum recommended for
the particular speaker type (see applicable
instruction).
__ 4. Refer to Figure 2 for connections to 1A2
Key Systems.
__ 5. Refer to Figure 3 for connections to
electronic line key or PABX loop start trunk
positions.
Settings
Wire Jumper JP1 controls the 15 second Repeat Alert
Tone. The Repeat Alert Tone is disabled with the
jumper in place and is enabled by cutting or removing
the jumper.
For off-hook speaker cancel circuit, each ICM "A"
lead must be connected through a 10K 1/4 W 5%
resistor to the inhibit input (GN/V) (refer to Figure
2). When "called" station or any other party goes
off-hook, the presence of two resistance grounds
cancels or turns off speaker. "Handsfree" mode can
only be restored by terminating call and redialing
station.
Volume Controls
The phone to speaker level should be at a normal
listening level.
Speaker to phone level: this is the most critical level;
set the volume at the lowest practical level. (It is
better to set it too low than too high).

OPERATION

To make a voice page, go off-hook and dial the
number of the desired zone or station. Dial tone will
be broken after the first number is dialed. A one-half
second ringback tone will indicate that the called
zone is being signaled. After the tone, proceed with
the page. If using the talkback control unit, called
party may answer handsfree. If speaker cancel is
wired, when called party goes off-hook, speaker will
be turned off.
To re-ring the same station, press the "*" button. The
station will be signaled as long as the "*" is pressed.
Personal signaling: When initiating a call, press the
"*" and then the station number. A double tone will
be sent to the called speaker. No voice announce or
talkback will be possible.
To dial a new number (tone dial only), press the "#"
button. The speaker for the first number will be
disconnected and dial tone returned to calling party.
Dial new number and page.
NOTE: If "#" is pressed after the speakers have been
inhibited additional numbers may still be dialed. A
tone will signal the called party but no voice
announce or talkback will be possible.
To achieve maximum performance from this system,
the user should receive the following operating
instructions:
a. The calling party should speak directly into
the telephone mouthpiece and avoid
speaking too softly.
b. The called party must wait (approximately
1/2 second) before responding to the calling
party.

CIRCUIT DESCRIPTION

General Method of Operation
This unit provides dial intercom access to interface
with the telephone system being used. A one-way
(V-119RTVA) or two-way (V-119RTHF) amplifier
conditions the speech from the telephone system tip
and ring, and provides a low impedance, low level
output to the desired speaker via conventional
telephone wiring, i.e. house cable or station wire.
Detailed Description
When a station user lifts handset to make an ICM
page, the switchhook contacts in the telephone close
the tip and ring to form a loop which returns battery
back to turn on a transistor which operates relay and
logic circuit to return dial tone and lamp battery to
telephone set. Logic circuit receives dialing
information and operates relays and circuitry to
supply splash tone and voice connection for station
selected. When called or any other party goes
off-hook on ICM path, the presence of two resistance
grounds cancels or turns off speakers if inhibit
resistors are wired. "Handsfree mode" can only be
restored by terminating call and redialing station.
3 947120M