So, yeah, it seems to be fixed

To rip off on last Sunday's dive into troubleshooting my audio oscillation problem in my ham shack. I haven't seen a single repeat of that issue since the one I described in a comment to that post on Monday  10/26.

After cleaning the two USB B connectors on the one side of the SignaLink I did last weekend, I did 10 tests of 10 transmissions on all five bands that my one antenna covers (a Tennadyne T6 log periodic) and the first transmission on the band that was giving me the most troubles started the comb problem. After Monday's test, I decided to move a clamp-on ferrite bead on the back of the SignaLink from one side to the other. Before I did that, though, I operated hours on that band (17m) without a repeat of the problem.

It looks like this now. That's the back of the SignaLink on the right edge of the photo: 

In this picture, the cable closest to the camera is the USB B (square) connector I cleaned with Deoxit5. It has one clamp-on ferrite bead now, but had two before. I moved the second bead just over to the next cable.

The connector closest to the camera is just labelled USB on the SignaLink box, and you can see that far cable looks more like a phone cable. That black plastic part between the molded part of that cable and the ferrite bead I moved onto that cable might well be holding a ferrite bead as well. 

From the pilot's seat, the station looks like this now. 

At the top of this frame, you can see a string of white LEDs that produce an even light in the area that I do things. You can see a piece of wood running left to right at the top, and that's the front of relatively large, table-like area, about 2'x6' (it has been years since I measured that, so it's a SWAG - but close). On top of that is the computer that controls all this, a huge monitor (well, 27" - biggest monitor we have) so I can watch several pieces of software running at once. There are my antenna and radio selector switches, the manual antenna rotator controller (I do that from the computer most of the time), a power distribution box and some odds. Or ends.