Rob: PS, Wonder if having all those radios connected to same antenna (if I
read you right) at the same time might be a contributing factor?

That's probably it. One time I had my DX-392 and B&H connected to the same
antenna. While tuning the 392, the Bellow & Howl screeched and the FET in it
died.

Unfortunately, a replacement FET, actual or sub, is not available, so I just
used what I had plenty of spares of, with resulting reduced sensitivity.

Bill, K5BY