Well, the problem didn't "cure itself", so I decided to take some
corrective measures.
1. I first switched a bunch of my jumpers around, and in doing so,
located a defective one that was in use. I cut off the bad end
(determined by flexing the coax at each connector and locating a
shorted connector) and replaced it. This did not cure the problem,
but did make me feel better about the problem not coming from
bad jumpers.
2. I re-worked my ground system, cleaned all the ground rod
clamps, and remade all the connections, then replaced the
corroded run of braid outdoors. I removed old extraneous braid
jumpers that were no longer being used from past projects. Still
no effect.
3. I noticed that the problem manifested itself the worst when I
could hear myself in the Ten Tec power supply speaker. I went
inside, and added a .01mF ceramic disk across the 12v accessory
connector. This was in common with the main wire out for the rig,
so bypassing here had the added effect of bypassing the main power
out. I found no trace of any bypassing caps in this area, although the
rest of the power supply seemed to be adequately bypassed. While
inside the power supply, I noticed that the speaker frame (somewhat
curiously) was isolated from ground, and had a pigtail of coax run
outside the power supply to be connected to the rig. I removed the
plastic washers from one mounting screw and replaced them with
metal washers to bring the speaker frame to ground. I then put a
.01mF ceramic disk cap from the speaker coax braid to this same
screw. I suppose I could have connected a piece of wire directly
from the braid to ground, but the last time I did this in my shack I
destroyed a half-dozen fuses in my Radio Shack DSP unit. Using the
cap keeps the speaker above ground while bypassing RF, and allows
my Radio Shack DSP unit to survive. (Ever wonder why they use a
plastic case on the R.S. DSP? I think they use a POSITIVE ground
inside this little beastie!) I thought about adding one on the "hot"
side
of the speaker, but didn't because I had no more .01's in the junk box.
I tried 40-10m with no complaints of RF on my audio. I will be trying
75m today, which was my "main" problem band. I have to get off the
internet beforehand as it always bumps me off-line when I'm on 75m.
I'm wondering if this is a symptom of too much RF in the shack? I
tried grounding my PC cabinet, and it did not help. Too bad I'm on a
small lot, or I could move my antenna away from being directly over
my operating position (about 25-30 feet up).
73 all, and thanks MUCH for the hints, -Web in Myrtle Beach, SC
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