Thomson TRC 3400 U229-U183 connector / digirig?

Hello everyone,
I have a thomson trc 3400 radio. I want to work in digital modes. The device has a u229/u183 connector.
I am sharing the link to the user manual of the device.

Can I operate Digirig device with this radio? Thank you in advance for your support.
De TA3KAH,73!

I hope someone can help. In my browser, I see an invitation to establish a file sharing account. The file you are sharing is listed as a pdf, but is not available.

73 Constrainted

Uploading: TRC3400 (1).pdf…
Thank you for the information. I am uploading the pdf file here.


TRC3400 (1)_compressed.pdf (850.1 KB)

We’ll need pinouts for these connectors:

As a minimum we need lines for audio in, audio out and PTT.

safety third :slight_smile:

Hmm, looks like these U-connectors are standardized.
Check out this post:

I have looked at this post before. this post made me think u329/u283 connectors would fit. I think it will be valid for 6 pin radios. I did not see any post about the pins of my device. It would be bad to hear that baofeng ht can pair with digirig but green devices cannot.:grin:

Thanks for sharing the info. There is definitely no issue interfacing as long as we connect correct signals:

  • GND (A) → 3.5mm TRRS sleeve (GND)
  • SPK (B) → 3.5mm TRRS tip (RIG_AFOUT)
  • PTT (C) → 3.5mm TRRS ring 2 (RIG_PTT)
  • MIC (D) → 3.5mm TRRS ring 1 (RIG_AFIN)

I placed an order. I will try this​:slightly_smiling_face::pray:

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I received the product. I will share my impressions after trying it…


I completed the installation. I paired it with digirig. I can decode sounds with wsjtx program. I must choose a suitable radio. Because I can’t do TX right now. Do you have any information regarding this subject?


Just flip the rings:


Thank you Denis :pray: i didn’t think of that
R1-R2 change

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Did it work?
What are the odds this becomes a product?
This would be compatible with practically all military radios

I made all the connections. I installed the driver. I tried it in the ft-8 application. It decodes sounds, but I could not choose a suitable radio. When I choose some models of Yaesu, it works the radio. but tx remains pressed.

@ta3kah Congratulations on the cable build! What ft-8 application are you using? If the Thompson radio is not listed, sometimes there is a “NONE” selection and then you choose “hardware PTT”. Other times, operators select “flrig” and use that middleware between the application and the transceiver.

If PTT works, and gets stuck on TX, then there may be an RFI problem. You may need chokes on cables or feedlines.

73 Constrainted


The rig dropdown selection is only applicable for the transceivers with the serial CAT control capability. This will also require serial cable connection and correct configuration of the serial port in Digirig. With basic radios select “none” and configure PTT by RTS on the right side.


Yes yes yes I made it.:pray::pray: I made the settings as you said and it works very well now. thank you for everything. The pin locations shown in the diagram are correct. If anyone wants to use it, you can write to me… 73!


Happy to hear about your success. Thank you for the confirmation of the pinout and settings.

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