Here are the relevant excerpts from the manual:
Based on this the audio cable for Digirig will look like this:
3.5mm TRS tip (DATA OUT) → 3.5mm TRRS tip (RIG_AFOUT)
3.5mm TRS ring (DATA IN) → 3.5mm TRRS ring 1 (RIG_AFIN)
3.5mm TRS sleeve (GND) → 3.5mm TRRS sleeve (GND)
RCA center (PTT) → 3.5mm TRRS ring 2 (RIG_PTT)
RCA shell (GND) → 3.5mm TRRS sleeve (GND)
Serial CAT control cable will look like this:
DIN pin #1 (GND) → 3.5mm TRRS sleeve (GND)
DIN pin #2 (S. OUT) → 3.5mm TRRS tip (RIG_RXD)
DIN pin #4 (S. IN) → 3.5mm TRRS ring1 (RIG_TXD)
I referenced other sources and the signal names in manual are apparently from TNC’s perspective. This is always confusing and manuals should be do better with this ambiguity.
Per note in the manual this should work with logic levels configuration, 4800 baud.
This serial CAT cable is the same as in TS-450 kit with the difference that pins #3 and #5 are connected for hardware flow control loopback in the transceivers exposing RTS and CTS signals there. This should not affect FT-736 because pin #5 is not connected there.
Radios that can use serial cable are:
- Kenwood TS-50 (with IF 100 installed)
- Kenwood TS-140
- Kenwood TS-440
- Kenwood TS-450
- Kenwood TS-711
- Kenwood TS-790
- Kenwood TS-850
- Kenwood TS-690
- Kenwood TS-940
- Kenwood TS-950
Please report your results if you decide to give it a go.