Page:
7 of 10
Model 1931888-3011 Page/Party
®
to Radio Coupler
Pub. 42004-245A
f:\standard ioms - current release\instr. manuals (42004)\42004-245a.doc
01/98
Time Out Timers
The coupler is equipped with two 2 timer boards labeled TMR #1 and TMR #2. The function of the
boards are provided to limit the transmission times of both the system and radio.
TMR #1
The TMR #1 board is controlled by the VOX board during party line communication from the
Page/Party
®
system to the radio. When VOX control signal is present at TMR #1’s pin 1 (system talk
mode), the output at pin 2 is pulled low to activate the VX1 relay. When party line audio is no longer
present on the line, the VOX output is removed and the VX1 relay drops-out to permit radio response.
However, if the station remains off-hook on the party line and noise levels occur, the VOX will detect the
levels on the line, and key the radio. Under this condition, the timer board will time-out and disable the
VX1 relay to remove radio keying control after approximately one minute.
TMR #2
The TMR #2 board is controlled by
SQUELCH
control from the radio to Page/Party
®
system’s party line
communications. When the
SQUELCH
control signal is present at TMR #2’s pin 3 (radio talk mode), the
output at pin 2 is pulled low to activate the SQ1 relay.
When radio
SQUELCH
control and audio is no longer present, the SQ1 relay drops-out to permit system
response. However, if the radio remains in receive mode with
SQUELCH
control, party line audio cannot
be transmitted back to the radio system. Under this condition, the timer board will time-out and disable
the SQ1 relay to remove radio
SQUELCH
control after approximately one minute.
Maintenance
Control Functions:
The Model 1931888-3011 Coupler contains four adjustment controls which have been pre-adjusted at the
factory. Minor adjustments may be necessary for optimum system performance. Refer to Figure 5.
Control Description:
•
UA VOL
: Adjusts the audio level being coupled to the Page/Party® or Call/Talk system from
the radio’s speaker out. Clockwise rotation of the control increases the audio drive level.
•
RADIO VOL
: Adjusts the audio level being coupled to the radio’s microphone-in circuitry
from the Page/Party® or Call/Talk system. Clockwise rotation of the control increases the
audio drive level.
•
VOX SENS
: Adjusts the threshold level (activation point] for the Voice Operated X switch
circuitry to activate. Clockwise rotation of the control increases the sensitivity level.
•
TRANSFER SENS
: Adjusts the threshold level for the TRANSFER detection circuitry to
activate. Clockwise rotation of the control increases the threshold level for
XFR
relay
activation when an associated Page/Party® station is off-hook.
