TX mode switching to Analogue without indication?

[barjac]

I am reporting this on behalf of another station (Steve) with whom I had a QSO earlier.

System is Windows 10
FreeDV is 2.1.0 @ #8e43

He was operating FreeDV RADEV1 and had obviously transmitted a proper FreeDV signal in the last few minutes as his call sign was in the RX Call column of the reporter showing that he had been heard by Brian G8SEZ.

I was tuning around and had just appeared on 60m and noticed his callsign on the reporter. I had the direct RX output of the radio set low and heard some weak SSB which turned out to be Steve. He was reporting as TX in the reporter, not decoding and was transmitting SSB!

We did more testing and set up another talk-back mode to try to resolve this. It became obvious that somehow the modem had switched to Analogue mode without the button being touched in the last few minutes despite it still displaying 'Switch to Analog'.
I suggested a reboot which he did and all was back to normal.
In hindsight we should have tried stopping and re-starting the modem, then same with the full program, then reboot. ...but that's hindsight for you!

During transmit it seems that there was nothing being displayed in the 'from mic' tab.
I have asked him to keep an eye on 'from mic' and if it happens again to try switching to Analogue and back to Digital again as a test.

Any ideas and has anyone else seen this I wonder?

[tmiw]

Haven't seen this personally but if anyone else has, please comment here.

Anyway, did the appearance of the Analog button change at all? Or was it still showing as though Analog wasn't triggered (yet it actually was)?

[g4dya]

I have heard this before but the problem wasn't in FreeDV-gui. It was just a configuration problem within the computer, where the audio from the microphone was inadvertently fed directly to the TX, bypassing FreeDV-gui entirely.

[barjac]

I have heard this before but the problem wasn't in FreeDV-gui. It was just a configuration problem within the computer, where the audio from the microphone was inadvertently fed directly to the TX, bypassing FreeDV-gui entirely.

Now you mention it this could be the same. But why it should grab a device that is already in use is very strange.

[tmiw]

I have heard this before but the problem wasn't in FreeDV-gui. It was just a configuration problem within the computer, where the audio from the microphone was inadvertently fed directly to the TX, bypassing FreeDV-gui entirely.

Now you mention it this could be the same. But why it should grab a device that is already in use is very strange.

Windows is known to do some weird things with audio devices, unfortunately. :( If this were happening on other platforms I'd have a higher suspicion for a FreeDV bug, but as it is, I'm not sure there's anything we can really do without a consistent way of reproducing (and even then, if it's a Windows bug we can't do anything about that either).

[Tyrbiter]

I would have been more sceptical about this, however as @tmiw knows it is possible for Linux/pipewire to suddenly decide to change audio devices without any user action as noted during our meeting last Friday.

[barjac]

I would have been more sceptical about this, however as @tmiw knows it is possible for Linux/pipewire to suddenly decide to change audio devices without any user action as noted during our meeting last Friday.

This is only about Windows not Linux. Its another user not me, I have pipewire under control :)