George,
You did not list the key info to solve this, how long is the ground wire to
the outside? If it approaches more than 1/8 wave on any frequency, it might
be the problem. Ground rods alone are lightning protection, not RF grounds,
in most solis unless wet.
Connect some quarter wave counterpoises for each band, and run them around the
baseboards of the shack, or out if close to the outer wall. Can use 16 gauge
insulated wire, as the ends will be a voltage point. Separate them if
possible.
Hope that helps.
A simple 10 turn coil of wire, 1 inch in diameter on a cardboard tube, would
make a sniffer you could use with scope or spare receiver to look for RF hot
spots while transmitting, you might try that, but the counterpoises are the
universal fix for your complaint. Works especially for those with upstairs
shack.
73, Stuart K5KVH
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