I had an unused GM1200 that should be interfaced to a SVXlink node. Turns out that it is not as easy as I thought. I wanted to use the CTCSS decoder and a hardware squelch signal. The CPS offers different options that can be programmed per FM channel. The essence is the option “Data Channel”. That enabled unfiltered raw output on pin 25 of the accessory connector. The audio input can be connected to pin 24. The hardware squelch can be used on pin 8. It carries +4.5V if the squelch is closed and drops to GND if the squelch opens.
