Another grounding question

[W1RKW]

I have separate AC circuits for the ham station, 813 rig, and test bench. Having the test bench on a different circuit is presenting a problem when using the instruments on the big rig and station equipment. What I'm seeing is the introduction of AC in my measurements particularly at low levels when using the test equipment on either station or the big rig so I suspect I have a ground loop that's effecting the AC operated instruments. It goes away if I lift the ground on the test instrument.  I'm thinking if I isolate the AC instruments with an isolation transformer I should be good to go. yes/no?  How does one deal with multiple circuits and grounds with various equipment and the possibility of the grounds of 2 separate AC circuits being connected together?

[WA1GFZ]

Bob,
Since you live in a new place I suspect you have good safety grounds but the lengths to the panel introduce 60 hz noise. You can use an isolation transformer but be careful because any line filters in the test equipment would put some AC on the floating chassis. Best to terminate the test equipment chassis to the rig under test so you don't get belted.