We’re getting into real classic rides here…
The AUX connector looked promising, but it’s lacking the signals we need
In this case we’ll have to interface the mic connector in front (GX16-6?) and EXT SP in the back:
Digirig audio cable will look like this:
GX16-6 pin 1 (MIC) → 3.5mm TRRS ring1 (RIG_AFIN)
GX16-6 pin 2 (STBY) → 3.5mm TRRS ring2 (PTT)
GX16-6 pin 6 (GND) → 3.5mm TRRS sleeve (GND)
3.5mm TRS tip (EXT SP) → 3.5mm TRRS tip (RIG_AFOUT)
3.5mm TRS sleeve (GND) → 3.5mm TRRS sleeve (GND)