Some further questions inline.
73, Reino OH3mA
>I only change during receive - it wouldn't make sense to do it in transmit.
R: Fully agree, hi. Do you Stop monitoring and Halt Tx before a band change?
>The connection is exactly as it was with 2.2.0, the ONLY change was to upgrade to 2.3.0.
R: I heard that also 2.4.0-rc1 may have that feature. I tested it also, but could not repeat the issue.
R: Well, in principle something RFI could happen just at the start of the transmission that prevent further audio. Need not be that, would require an oscilloscope to check that. I doubt it for the moment.
>The CAT control has no issue putting the radio into TX, there's just no audio. If I use the "halt Tx" button, and then "Enable Tx" while responding to a CQ, there's no audio.
R: So after changing the band you have received a full timeslot to spot somebody and double-clicked his call, I assume. And your Tx has gone to transmit at the beginning of next appropriate TX cycle, but no audio. After noting that you use “halt Tx” and “Enable Tx” and still no audio. Or did I missed something? Or do you have “Double-click on call sets Tx enable” unticked and you use “Enable Tx” to invoke transmission?
>To get audio to start again, I have to initiate a CQ, then "Halt Tx" and "Enable TX", sometimes 2 or 3 times.
>I just verified that, indeed, doing a "Halt Tx" and then "Enable" during a TX window will restore audio output. Sorry, I hadn't tried that thoroughly before.
R: So the “halt Tx” and “Enable Tx” sequence invokes audio during that TX slot.
In any case I have not managed to repeat it, but now I have used WSJT-X without any rig, just audio. I have assumed that audio is sent at the same time as CAT has commanded PTT on. By the way which PTT method you are using and which rig we are talking about? We have some unknown issue in your system.
73, Reino OH3mA