[TenTec] Oll & RF @mic input.

[Stuart Rohre]

Try coiling up part of a mike cable into an orderly solenoid coil, NOT 
scramble wound.  You can put it on a pop bottle or other pipe form for a 
test.  If that works, you can measure and compute what inductance it was 
and replicate it with a ferrite core, passing the mike cable thru and 
around that for fewer turns.

If you want to get deep into the radio, see if there are ferrite beads 
on the mike connector wiring, and if not, add that.  Beads web sites 
usually have application notes on how much equivalent inductance you get 
per bead and you can put multiple beads if there is room.  Insulate the 
beads from contact with chassis or other conductors.

-Stuart
K5KVH