This morning the rig would not go into transmit via wsjt-x. It worked fine last night up to when everything was shut down and there were no changes to anything, hardware or software. Rebooting the PC made no difference. CAT control was working both ways and it was receiving FT8 fine. I noticed that transmitting would sometimes change the rig settings e.g. from data to non-data.

I tried the flrig / fldigi combination but transmitting via this messed the FT450D’s settings up in that it was rapidly triggering tx and the rig decided to engage its internal tuner.

Plugging the two USB connectors into the front USB sockets on the PC made it work but the transmit levels are mad – ALC is triggering and the rig does not generate any decent power with this turned down. ALC is on a knife-edge where it goes from very little power / no ALC via the SignaLink TX control to 50% ALC and proper power output with nothing in between. Fiddling with the audio settings on the PC and in wsjt-x makes little difference.

But changing the Mode to Data/Pkt in Settings -> Radio does improve the ALC business. This was set to None and I cannot remember if this is a change or not.

The audio settings via pavucontrol are set to 100% for the USB audio. This was 120% before as otherwise the rig would keep falling out of Tx on 40m. Wsjt-x’s tune function is holding up on 40m at 100% so there is a change there for no apparent reason.

All the PC USB ports are USB2.0 so there is no difference there. Trying a few CQs on 17m shows that FT8 is being received across Europe so it is all working. The same is true to 40m.

Weird. The only physical differences between it not working at all this morning and now are the two USB cables are plugged into the front sockets and the USB leads are away from the antenna coax. But the latter, i.e. the cable routing has always been along the same path as the coax and it has worked every day without issue.