Midian RT-2 - Hardware Alignment; Radio Programming; Operation

HARDWARE ALIGNMENT
RX Audio Input: On the RT-2 adjust R65 so that Pin 14 of U2 (TP1) doesn’t quite clip when a 1 KHz tone
modulated at 3.3 KHz deviation from a signal generator is applied. Additionally, monitor TP2 (U2 Pin 8) for a clean
symmetrical square wave. If more level is needed remove R63 by cutting JU1.
TX Audio Output: In a wide band system, set the modulation pot R22 to 3.3 KHz (66% of 5 KHz) of deviation per
EIA specifications. In a narrow band system, set the modulation pot R22 to 1.65 KHz (66% of 2.5 KHz) of
deviation per EIA specifications. Set CTCSS deviation to 750 Hz – 1 kHz. In Low-Z mic circuits, it may be
necessary to short R23 and/or increase C20.
RADIO PROGRAMMING
The RT-2 is a generic module that wires into most radios. Any radio specific programming, if available, would be
found on any Application Notes available for those radios. You may visit our website or call us for application
notes.
OPERATION
Decode: Upon decode the unit will ring, via the Alert Tone/Speaker Audio line, according to the ring code
programmed. The unit will also give the following outputs depending on the hardware configuration:
1. Momentary Horn Output: This will give an open collector output to ground for 1-9 seconds/minutes depending
on the programmed horn time.
2. Latched Monitor/Squelch Output: This output can either go from low to high or from high to low. With JU-5
installed and the squelch polarity programmed for V+ the output will go from high to low. With JU-6 installed
and the squelch polarity programmed for Ground the output will go from low to high.
3. Disable Output: If used, the Horn Output is not available. It will be necessary to reconfigure the hardware
jumpers from the Horn to the Disable line. To use this output it is necessary to program the ring code as “Unit
deadbeat disable”. Upon receiving the decode sequence the output will latched and stay latched until it
receives the sequence again.
Resetting of Outputs: The momentary output will automatically reset after 1-9 seconds/minutes depending on
how the unit is programmed. The Monitor/Squelch output can be reset by cycling power, sending another
sequence with the ring code of “Turn off call lamp/mute” or by grounding the monitor input. These reset options
depend upon the programming of the unit.
Transpond: If programmed under the Transpond Mode field, the unit will key the PTT Output generate a tone or
tone sequence via the TX Tone Out wire. Transpond only works on Decode Register 1.
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