Hey, John, N3AAZ,
Many thanks for the hint about the "variable (tunable)" audio filter.
I've been wanting to improve on my 7-band QCX rig's performance while receiving, for example, CHU on USB on its three freqs, as well as AM SWBC, JS8, FT8 etc on all my QCX-17's freqs !
72 / 73,
Bill, N4QA