I have a TM-431A which I want to use as a half-duplex link. I can easily get audio in and output, but I'm stumped on how to get a voltage change when the squelch opens for COS (Carrier-operated-squelch)
Ideally I'd like a voltage that swings only when the CTCSS is detected as well as squelch open, but I'd settle for one that is just the squelch. My controller is an ICS linker. Does anyone know the proper point to connect to, or does anyone have a service manual for this unit? Thanks, Jeff WB0LRX