Dave,
When I started this process, I loaded the OEM firmware on the new Nano (actually two of them). I also copied the eeprom data from the original OEM Nano to the new ones. In both cases, the BFO cal couldn't be accomplished.
Then I loaded CEC firmware on the two new Nanos, but BFO cal. was not possible. Today, I tried 2 variations of CEC firmware (NX and NX_S), in case one was corrupted. Same result.
As noted in previous posts, with the new CEC Nanos, the clock signal bandwidth looks abnormally wide. With the original OEM Nano, the clock signals are narrow. So... maybe I have two bad Nanos (although Mark H. told me he has never seen a bad one).
I loaded CEC firmware (NX only) on the original Nano. The clock signals have broad bandwidth. BFO cal doesn't work.
I loaded OEM firmware back onto the original Nano. The clock signals have broad bandwidth. BFO cal doesn't work.
(Note: The OEM firmware was loaded with Arduino IDE. I did not edit anything, assuming that the default settings are right for the original configuration.)
So, I guess it's time to swap boards with Mark and see what happens.
