[TenTec] RF Feedback on Omni VI (opt 3)

[Mark Erbaugh]

My Omni VI option 3 upgrade has developed symptoms of RF feedback. I got a
report of RF in my transmitted audio. I'm also hearing muffled audio in the
speaker or headphones when transmitting. I get this problem even when
transmitting into a dummy load. The muffled audio in the speaker seems
pretty much the same whether I'm  on 75m or 10m.

My Pegasus is sitting next to the Omni VI. I moved all the cabling from the
Omni VI to the Pegasus. The Pegasus doesn't appear to have the RF feedback
problem.

My ground isn't ideal. I have about 15 feet of RG8 coax braid going to the
copper ground wire that runs from the electrical panel to grounding rods
(2). There is about 8 feet from where the braid joins the ground wire to the
ground rod. So I guess my total length to ground is about 23 feet.

I do plan on shortening the path to ground and using heavier wire, but
that's going to require drilling through the poured walls of my basement.
The two ground rods for the electrical system are just outside the wall of
my shack (about 6 feet apart). By drilling through the basement wall, I
should be able to get the total length to the first ground rod down to six
feet or so. Is it likely that a third ground rod for the shack (but
connected to the other two) would help?

Any ideas?

Thanks,
Mark