Cable for Motorola MCS2000

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Based on the above pinout sourced from the depths of the interwebs the audio cable to Digirig should look like this:

Pin #11 RX Audio → 3.5mm TRRS tip (RIG_AFOUT)
Pin #23 Mic Audio → 3.5mm TRRS ring 1 (RIG_AFIN)
Pin #21 Mic PTT → 3.5mm TRRS ring 2 (RIG_PTT)
Pin #10 GND → 3.5mm TRRS sleeve (GND)

Please share your results with this build.

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I have a bunch of MCS2000 here and would like to test with my Digirig. I’m assuming the Motorola RIB wouldn’t be in the circuit, and you’d connect direct from the Digirig to the radio DB25 port? Some information I’ve found says the RIB converts from RS232 voltages to TTL needed by the radio, so if that is true which configuration of the Digirig would be most suitable - would the default logic levels config work ok?

For your pinouts - Pin #11 is filtered audio out. When building mmdvm based digital repeaters out of these radios everyone typically uses pin #25 for discriminator audio. Not sure if it matters for the digirig?

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Yes, you should be able to directly interface Digirig to the radio without any additional adapters.

Re. serial levels: Digirig’s serial port can be configured to match the electric levels directly at radio’s serial port (TTL logic levels or RS-232).

Re. audio: for digital modes connect the widest band (least filtered) audio. Digirig meets and exceeds any audio bandwidth requirements in radios by wide margin.

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Confirmed with a 2m MCS2000 (K-split) radio with Direwolf sending and receiving APRS packets with the following cable connections:

Pin #25 RX Audio → 3.5mm TRRS tip (RIG_AFOUT)
Pin #23 Mic Audio → 3.5mm TRRS ring 1 (RIG_AFIN)
Pin #21 Mic PTT → 3.5mm TRRS ring 2 (RIG_PTT)
Pin #10 GND → 3.5mm TRRS sleeve (GND)

Also the MCS2000 requires the following jumper to prevent an error at startup:
Pin #9 Emergency ↔ Pin #4 Digital GND

Cheers.

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