User's Manual

DB-15 Pinout Description
Pin Number Description
1 CS0- Least significant bit of the channel select lines. Active high 5 volt
TTL/CMOS level. Internal 10 k pull-up to +5 volts.
2 CS1- Mid bit of the channel select lines. Active high 5 volt TTL/CMOS level.
Internal 10 k pull-up to +5 volts.
3 CS2- Most significant bit of the channel select lines. Active high 5 volt
TTL/CMOS level. Internal 10 k pull-up to +5 volts.
Channel CS2 CS1 CS0 0 = Logic low
1 0 0 0 1 = Logic high
2 0 0 1
3 0 1 0
4 0 1 1
5 1 0 0
6 1 0 1
7 1 1 0
8 1 1 1
Note: Due to the internal pull-up resistors, the unit defaults to Channel 8 if
Pins 1, 2, and 3 are left open (unconnected).
4 AUDIO IN- Microphone input. This input accepts microphone-type input signals
for transmit.
5 HI/LO- This input selects between high and low RF output power. This input is
TTL/CMOS level type input with a logic low required for low power and a logic
high required for high power. Internal 10 k pull-up to +5 volts.
6,7 RELAY 1- Normally open contacts of Relay 1. Contacts are rated for 5A @
6VDC. The output can be configured for Normally Closed.
8,10 RELAY 2- Normally open contacts of Relay 2. Contacts are rated for 5A @
6VDC. The output can be configured for Normally Closed.
9 PGN IN/OUT- Connect via RITRON DTXT-PCPK PC Programming Kit to
computer for programming the unit.
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. Note that this
output level varies with the adjustment via the programmer of the AUD OUT
level.
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- Push to Talk. 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.