IC-706 MKII PTT failure

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1

I’m asking the same thing others have asked, but nothing that was suggested in other threads works for me. I’m going to try to exhaustively document what I’ve configured / tried.

I’m using a Mac running Sequoia 15.6.1.

I have a Digirig Mobile configured for CI-V. I opened it and it looks like the correct pads are soldered (the top row’s middle and right pads and the middle row’s middle pad are all bridged with solder.)

The Digirig Mobile is recognized by the Mac as a USB to UART bridge controller with Vendor ID 0x10c4 (Silicon Laboratories, Inc.). Its location is 0x00114100. This tells me the Mac can see the Digirig.

I got a “Icom IC-706 Digirig Cable Set”. The “remote” is plugged into the radio. The green end is plugged into the green port on the Digirig. The Icom Mini Din13 connector is plugged into the radio and the regular black end is plugged into the Digirig.

The 706-MKII has the following settings:

13 PTT TUNR: ON

25 CI-V ADDRES: 4EH

26 CI-V BAUD: 9600

27 CI-V TRN: OFF

28 CI-V 731: OFF

On the Mac’s Sound control påanel both the input and output are set to “USB Audio Device”. This tells me the Mac can see the Digirig.

In WSJT-X (v. 2.7.0) I have the following configuration:

Rig: Icom IC-706-MkII

Serial Port: /dev/tty.usbserial-11410

Baud Rate: 9600

Data: Eight

Stop: Two

Handshake: None

Force: DTR empty; RTS empty

PTT Method: RTS on port /dev/tty.usbserial-11410

Mode: None

Split Operation: None

Test CAT works. I can see the radio switch between VFO-A and VFO-B a few times and see the frequency shift and return to the starting frequency. This tells me CAT control is working.

Test PTT immediately turns red. No errors are given except the red button. The radio never tries to switch to Tx. The same thing happens if I choose Tune in the actual program.

Decoding is happening correctly. I see FT8 messages. Frequency change is happening correctly if I switch FT8 bands. This tells me the Mac is processing the audio going through the Digirig.

I’ve seen the Digirig troubleshooting PTT YouTube video. If I short the sleeve and R2 ring the radio switches to Tx.

However. I can’t seem to make the second troubleshooting step work. If I test continuity on pins 2 AND (3 OR 7) while Tune-ing in WSJT-X or by testing PTT nothing happens. This is a little hard to test with two hand, a connector, two probes, and a mouse button to press, but I gave it a good long try. It’s hard to prove a negative, but I couldn’t get it to respond to the Tune in WSJT-X.

So now I’m stuck. Any ideas? (and thanks if you’ve read this far).

2

Do you have access to a windows machine to rule out either the computer or Digirig’s hardware as the source of the issue?

3

More testing.

The cable I got is this: https://digirig.net/product/icom-ic-706-cords-for-digirig-mobile/. I have continuity between the sleeve and pin 3, between R2 and pin 2. If I short the sleeve and R2 the radio’s transmitter turns on.

I’m going to focus the rest of this on testing the Digirig module. I think I can isolate the problem to the module, not the radio.

According to the troubleshooting video (https://youtu.be/1EtrkyisCnc?t=233) I should be able to detect PTT by using an ohmmeter, black on ground (pin 2), and red on PTT (pin 3, the HF pin). I’ll try this a couple of way on a Mac, and on two different Windows machines, one Win 10 and one Win 11.

Mac: I installed WSJT-X. I did not install the Silicon driver, but the card works for CAT control and decoding FT-8, so I believe it is working. I unplugged the Digirig from the radio. It is only connected to the computer. In WSJT-X I choose “none” for the Rig. On the PTT Method I choose RTS. I close the configuration and click Tune. Nothing happens on the ohmmeter.

Windows 10: I tried fldigi with identical results.
Windows 11: I did have to install the driver, but I got identical results in WSJT-X.

I’m happy (kind of) to keep testing, I just can’t think of anything left to test.

4

Thank you for additional info. It sounds like your test with WSJT-X on Windows involved measuring the resistance. This test is a bit tricky. Did you have a chance to try it with the radio connected?

5

I’m not sure how to test PTT with the radio connected since the pins would be in the radio. But, for grins. I hooked up the green serial cable and did the same test to no changed effect (with the DIN cable unplugged so I had access to the pins, the testing has never worked with the DIN cable plugged into the radio).

6

I’m referring to connecting the cables between the Digirig and radio as intended and doing PTT by RTS test via WSJT-X.

7

I see. On my Mac and on Windows they both fail to put the radio into Tx when I hit the Tune button in Wsjt-X. I also tried WSJT-X Improved in Windows since it has a more recent Hamlib, this also didn’t work.

8

PTT failures are very rare, but still possible.
Let’s get your unit in for service and I’ll re-test it and repair if needed. RMA details are in PM.

9

Got the Digirig unit in question. This one was a genuine hardware failure - the ring 2 lead of the audio socket dethatched from the PCB pad. A quick retouch of all solder joints of the audio socket got it fixed.

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