[TenTec] TT 1220 problem

[Stuart Rohre]

No specific experience with the whine, but a general capacitor test is to
parallel temporarily a new cap of equal or nearly the same value as the
electrolytics under test.

If hum goes away, you may replace that cap you tested.

Some DVMs will approximately test caps in circuit, and that is a way to find
open caps of the mF sizes.   Hum would normally be a result of a smaller
than normal or open cap.  It is possible the factory tested the rig on a
dummy load and overlooked a qualitative check on the air.  It could also be
some kind of feedback path between the rig and other accessories.  Check all
jumper coaxes for bad shield grounds end to end.   Eliminate antenna
switches, SWR meters etc from the rig to antenna path and test again.
GL,
Stuart
K5KVH