(tr)uSDX with Digirig (rev 1.9) and Soundmodem

I cannot figure out what PTT setting to use in Soundmodem when using a Digirig. I’ve got two audio cables from the Audio and Mic/Key sockets of the (tr)uSDX going into the Audio socket of the Digirig (rev 1.9). The Mic/Key audio jack is modified according to the pin-out instructions by DL2MAN. Soundmodem wants me to select a port for PTT. What do I select? I tried selecting COM12, which is the port that the Digirig is connected to. Nope. If I select CAT from the drop-down in Soundmodem, it wants me to select a radio, etc. Is the Digirig sending CAT commands? I don’t think so. What radio should I select here?

I thought that when you just use the audio cables, you are only keying PTT through the Mic/Key connection. So no CAT.

This question is specific to Soundmodem. I don’t want to hear about WSJTX, flrig, etc, etc. I’ve got all those working by other means.

yes, you would select whatever com port the digirig occupies.
(yes, this is also the comport ‘number’ you would select IF you were passing ‘CAT’ commands on the OTHER jack of the digirig)
same comport number for either action. cat/ci-v AND ptt rts toggle
rts should be selected.

that should do what you’re wanting.

audio cable only from the digirig that will trigger ptt via comport rts ‘toggling’.

good luck

Like I said, I selected COM12 and it didn’t work. No PTT keyed.

@K7DMJ that sounds frustrating. If you think the issue is configuring soundmodem, please post some screenshots of your configuration.

If something more is going on, the guide Digirig Mobile Rev 1.9 – digirig features this video explaining about PTT:

There is another guide, Troubleshooting Digital Modes – digirig, which features a step-by-step guide to working through PTT:

My experience with Digirg and truSDX has been successful with this configuration:

  1. USB with ferrite bead from computer to Digirig
  2. @K0TX audio/PTT cables from Digirig to truSDX
  3. hardware PTT/RTS to the MIC/PTT 3.5mm input on the truSDX
  4. power 8-10V on the 12V barrel jack to PS, or power 5V on microUSB to battery.

If you limit yourself to this approach, and I think you are, you will quickly succeed with any of the digital modes.

I have had inconsistent success with using CAT control via microUSB, and CAT+Audio via microUSB. Others succeed.

If you have both the Digirig and the microUSB data cable connecting the truSDX to the computer, you will be presented with two new COM ports. The Digirig requires the SiLabs CP210x driver and the truSDX needs a driver for a CH340G usb-uart bridge. I never use the computer to power the truSDX via USB, always battery.

Please be careful to consider if you are using audio cables which DL2MAN has designed to support CAT control via microUSB.

73 Constrainted

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I just ordered the cables sold on the Digirig website for the (tr)uSDX. I had been using the modified audio cable described by DL2MAN, assuming that Denis would have used the same pin-out to avoid inadvertently keying the radio. I’ll see if the new cables make any difference,

Update: Received the cables from Digirig and used them for the audio, with CAT control via the (tr)uSDX USB port. Ugly wire mess with two USB cables going into the computer. But that works. I assume that I could probably use RTS through the (tr)uSDX mic input to key PTT and just live without CAT if I wanted to eliminate one of those USB cables. But I’m not sure how that can be achieved in the Soundmodem software. Suggestions?

Could you post the output of Windows Device Manager for the Serial Ports? Then post the configuration Tab of soundmodem? With that information, I will be able to offer guidance.

73 Constrainted