Thanks for the thought Dean, however, I replaced the TCXO module with the crystal and C2 then did a factory reset, so I'm back at 27MHz which, I think, is right.
Howard, I've got to say I had a weird notion that by testing with a 9V battery, I was less likely to see the infamous puff of smoke. However, I have taken your advice and am now testing with a 13.5V bench power supply. I don't have a current limiting one, but I went for it.
The rig is drawing 0,09W on receive, and 0.43W on keydown. Does that sound right? No smoke either.
I can also report that my dummy load/power meter was, when I first tested with the bench supply, showing 3.3W on keydown but, for no obvious reason, this has now dropped to a fairly consistent 1.84W
Option 8.7 Peak BPF is still showing unstable values of 00, 01, 02. Fluctuating without me adjusting the trimmer capacitor.
Sometimes, there appears to be a problem with the 8.7 Peak? BPF display. It will show a relatively high value in the top right hand corner 8, 9 or 10, but without any bar graph movement. Turning to options 8.8 or 8.9 invariably shows the same high value and no bar graph movement. Switching off the rig for a few minutes appears to correct this problem
The loud tone in the headset persists, it is not the 700 Hz tone I would expect when selecting option 8.7, but it does alter in frequency slightly when I adjust the trimmer capacitor.
As always, your very patient suggestions are most welcome.
Best,
Les
MM0UMH
Les/MM0UMH