Hi Jerry,
These are all good ideas for self testing/debugging the uBitx.
One additional thing occurred to me. Rather than try to calibrate the dial frequency by attempting to zero beat WWV or listen to the sound of an AM radio station, it might be a good idea to have a test connection point to attach a short piece of wire to one of the?Si5351 outputs and be able to dial the frequency to a known AM radio station and listen for the zero beat on an AM radio. (Likely everyone has an AM radio) Then whatever the difference between the frequency display and the known AM radio station frequency could be input to zero/calibrate the the uBitx dial frequency. Should be simpler, more direct and reliable than the current method to calibrate the dial frequency (unless the calibration method has been updated in the last year or so). Not sure how accurate the DVMs are as frequency counters, but still a great way to ballpark check things.
Also, using the log detectors are a good idea, although a diode RF probe should still be a backup plan. I bought a couple log detector modules a while back. This will be a good use for them.
I remember the good old days when you could zero beat to WWV, now with the time code modulation plus tones on WWV, I found it very difficult when I tried more recently.
Tom, wb6b
