ohms. Therefore, it is not recommended that this output drive loads with less than
1000 ohms unless the resultant voltage drop is accounted for.
9
PGN IN/OUT-Connect via RITRON DTXP-PCPK PC Programming Kit to computer for
programming the unit.
10
CTS-Clear-To-Send output from the unit which indicates that the unit is transmitting a
carrier at the correct frequency and power level and is ready to accept an input signal to
be transmitted. This output would normally become asserted in response to a PTT RTS
(see pin 14 description below) activation. The polarity of this output can be programmed.
The output is active low 5 volt logic with an internal 10 k ohm pull-up to 5 volts. It can
source up to 10 mA when low.
11
RX MON-This input breaks the squelch (unmutes) on the receiver i.e. allows for
monitoring the channel even when a signal not strong enough to break squelch is present.
Input levels are TTL/CMOS; polarity may be programmed. Internal 10 k pull-up to +5
volts.
12
AUDIO OUT-This is the output of the audio power amplifier. This output can drive up
to 100 milliwatts into an 8 ohm load. The output level can be controlled by
programming. De-emphasis can be applied to this output, but not independently of the
AUX OUT output.
13
DCD-Carrier detect output. This output becomes asserted when a signal strong enough to
exceed the programmed squelch threshold is present. This output is not affected by the
RX MON input. The polarity can be programmed. The output is active low 5 volt logic
with an internal 10 k pull-up to +5 volts. It can source up to 10 mA when low.
14
PTT/RTS-Push to Talk/Request to Send. This input commands the unit to transmit.
Input levels are TTL/CMOS; polarity may be programmed. Internal 10 k pull-up to +5
volts.
15
GND-System ground. All signals and voltages are referenced to this input. The negative
side of the power supply should connect here.
