Tonight I finished boxing up my BITX20 Version 3 into a new box.
I went to particular effort to make it neat and tidy so that If I need to fault find it I won’t struggle too much.
I took some photos and then powered it up. At first I thought things were good as the display came on with the start up message and all looked OK.
But then the start up message went and I was left with a display showing 9.9972 MHz. This is the offset count for the display. This says to me that the PA3CNO huff and puff display circuit has no input from the VFO.
The VFO seems to work as I could tune around and receive a couple of broadcast stations.
I pressed the PTT button and I get a carrier even when I have no modulation. This could be a simple tuning issue as I expect all my oscillators need to be re-aligned now that the boards are mounted near metal inside the ABS case.
I will go through the circuits tomorrow and see if I can find the problem. Perhaps I have the VFO sense and the VCO control cables swapped over?