So Is It Fixed?

Followers of yesterday's post on the problem I'm having with my station have probably read my description of today's work, but I copy it here for everyone else. 

The most effective thing I did yesterday was to unplug and replug the USB cable into the audio input box on top of the rig. It's one of those square plugs, about 1/4 on a side, so I think those are USB A family. Today, I tried the station the way it was last night and it was doing better. I did about 10 transmit tests before it went into the "audio comb mode". Once I reset everything, I grabbed my can of "Deoxit 5" spray that's always on hand and gave a small spray into the end that plugs into the audio box on top of the rig.

Since then, I worked a couple of stations on 17m, figure about 10 T/R changes (both to and from that box), for them and ran around three dozen "tune" button transmissions. No returns of the "comb". 

So given that connector issues like this are about as common as can be - although I can't say I've seen one with these square USB-B connectors - and since I've done lots of transmissions without seeing the problem again, it might well be "all better." Between working the two new countries on 17m and my roughly "three dozen" transmit tests, that's more than I tend to transmit in most full days of making contacts on any band. 

Let me add some info that I should have included last night but wasn't prepared. 

First is the "red comb" effect, at the top of this screen capture. From the start of continuous lock out of the system until this screen grab is five 15 second intervals, and this was early this afternoon before the Deoxit5.

I've seen the red comb continue after I've turned off the radio that had been transmitting, so it's got to be coming from the audio system. The transmit audio is generated by the WSJT software running on the PC that gave us this plot. The audio from the computer goes over the USB cable that appears to have fixed it. That goes to a SignaLink USB box that controls both the transmit and receive audio levels. 

It has been a tricky problem to work on because it seemed different at different times. On the first day I spent time testing other bands, I found it on 20m and while I'm not 100% sure at the moment, I'd swear I saw it on 15m. I haven't seen it on any other band as much as 17m, and none on 20 and 15 since Thursday. Intermittent or "flaky" problems can suck up a lot of time.

So while I think it might be fixed, I'll be keeping an eye out for milder issues or more cases of this.