Dave, Does the built-in TR-7 reflected power meter jump to infinity?
A couple troubleshooting suggestions: Disconnect the antenna and feed the TR-7 directly into a dummy load. Disconnect the mic and see if this happens on CW. Good luck with it. Tom, AG9X On Sat, Oct 16, 2010 at 9:19 AM, K8JDC <k8...@sbcglobal.net> wrote: > Gents, > > My TR-7 started doing something unusual this morning. I tried to check > into a 40m phone net and I noticed my external VSWR meter going crazy. It's > a dual-needle type and I would start talking and things would be okay and > then the reflected needle would instantly jump to infinity. Unkey and try > again and it would do the same...normal for a second or two and then a jump > to infinity. I think I saw the same behavior when I first got this radio > and did the full alignment when adjusting the two big power output pots and > it went into oscillation. (I don't recall the exact names of those pots but > I recall one was in the PA section and one underneath the radio.) My radio > seemed to be a little touchy to those adjustments and wanted to oscillate > but all has been well for the last 18 months or so until this morning. As > luck would have it, I recently rebuilt my microphone cable, re-arranged my > ham desk, and adjusted my antenna slightly so I've touched about everything > but I can't find any evidence that I have any kind of flaky connection in > the antenna as that was my first thought given the reflected power > indication. The problem is that the reflected needle just goes from zero to > infinity and I think that's exactly what it did when it went into > oscillation. My VSWR meter uses an inline directional coupler arrangement > (Palstar WM-150)on the input to the tuner. The receive strength is rock > solid and we have no wind whatsoever on the antenna today. I tried reducing > mic gain and so on but the problem still happens. It doesn't necessarily > make sense to me that oscillating would cause the VSWR needle to jump but > I'm pretty sure this is what it did when I adjusted those pots about 2 years > ago. Thought I would check with the experts before dragging it out of the > operating position and trying to adjust those pots. > > Thanks... > > Dave > K8JDC > > _______________________________________________ > Drakelist mailing list > Drakelist@zerobeat.net > http://mailman.zerobeat.net/mailman/listinfo/drakelist > _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
