I have not yet attempted to power the board from an external supply, but it’s something that I should try. I’ll just have to acquire that particular plug to do so. The lower bandwidth (2.5, 5, 10) as I mentioned in another reply this morning does not change the amplitude or frequency of the spurs appreciably outside of the expected differences in the “binning” of power in the FFT. The proper term for spreading the power across multiple FFT bins escapes my memory for the moment.
I may have to also experiment with shielding. Thank you Tom,
Joe