PTT not working for Yaesu FT-65 or FT-4X - not a DigiRig problem or DigiRig cable problem

I found below info here:

Audio IO

Motorola M1 connector

  • 3.5mm :
    • Tip = speaker- (Vcm = 2.5V)
      • Jumps to 2V when squelch is open. Audio max = 4V (with respect to GND)
    • Ring = ?
      • internal 10K PU to 3V3, unknown purpose
      • Short circuited to sleeve when using the SSM-17B Hand speaker Mic. Maybe that’s the reason why Yaesu doesn’t market the SSM-17B as an accessory to the FT-65. The SSM-512B is advised instead.
    • Sleeve = speaker+ (Vcm = 2.5V)
  • 2.5mm :
    • Tip = Connect a PTT switch in series with electret-MIC (1K8 or 2K2 internal resistance) connected to GND. Function generator outputs must be AC-coupled to this input, otherwise the PTT functionality no longer works correctly.
    • Ring = RX/TX line
      • RX/TX Short circuited to sleeve when using the SSM-17B Hand speaker Mic.
      • Use open drain TX and connect it to RX.
      • To interface to a standard UART: connect the anode of a diode to the UART-RX. Connect the cathode of that same diode to the UART-TX.
    • Sleeve = GND

This confirms that we are absolutely safe using TS (2 pin) connectors on both sides.
Now the issue you are reporting is likely to do with the mechanical fit. I did overlay of parts of the photo you shared and it confirms what you observed: that the tip part is of different length on 2.5mm side between Digirig cable and speaker/mic.

There is a good number of these cables out in the wild, but this is the first time that I remember this issue coming up. I’ll keep it in mind when reordering this model.

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Thanks! I appreciate it and I would be happy to test any revised cables.
But as far as the SSM-17B goes, that’s exactly what Yaesu lists on their accessories page for the FT65R:

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I think I found a matching connector. Will prototype with the next order and reach out for testers.


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Wonderful. Please let me know how I can help.


Hello! I am so happy to have found this thread, I had to make an account to reply right away.

I have the exact same problem with my FT-4X but kept thinking that I was doing something wrong until I was able to build a cable for my AnyTone at-778uv and confirm that it works as expected.

The cable I’m using is the coiled digirig cable that looks exactly like the one smshannon55 posted pictures of. Any chance I can get in on the replacement/testing bandwagon?


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Welcome to the forum!!

I’m sorry for your frustration, but relieved (selfishly) that I’m not the only one to have this issue. I’m not the person who can help, but I wish you well!


I’ll make an announcement in the thread when the replacement is available. Please stay tuned.


Denis got a prototype cable to me and it works.


Awesome, I’m excited to hear that it’s looking good so far.

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