Hi, all.

Well, Bob Heil checked out my Heil GM5 mic, Kenwood interface cable, and FS2 
foot switch in his lab with his TS480 and amplifier, and couldn't replicate 
my 20-meter RFI problem.

So, it looks like it's back to the drawing board for me.

You may recall that I had the original RFI problem when using my Alpha Delta 
DXCC antenna, and when using the FS2 foot switch, so, I think something is 
creating an RF ground loop somewhere.

You also may remember that if I plug the amplifier cable on the foot switch 
directly into the amplifier relay jack, it partially keys the amplifier, 
even without my pressing the foot switch.

I am considering four things to try when I get back home from Missouri:

1.  Trying the original set-up on my Carolina Windom 160 Compact, since that 
antenna was not working when I initially experienced the problem.

2.  Taking the ARB704 buffer box completely out of the circuit, although I'm 
not sure how I'm going to directly hook up my  Ameritron AL811H amplifier to 
the remote jack on the TS480.  The remote interface cable I now have has two 
mini-din plugs, while there is no jack to accommodate such a plug on my 
Ameritron amp.

3.  Purchasing and installing the 1 to 1 line isolator balun from the wire 
man that Kevin suggests, at least for the Alpha Delta DXCC antenna;  and

4.  Making a 20-meter counterpoise wire like some suggest, with one end 
connected in the shack, and the other hanging out the shack window. 
Regarding that counterpoise wire, should it be 15 or 16 feet long, and where 
do I connect the shack end?--to the ground lug on the TS480, or to the 
common ground lug on my MFJ window feed through panel?

If anyone has comments on any of these four strategies, or if anyone has any 
other suggestions of things to try, please let me know.

Thanks, and 73 from Tom Behler: KB8TYJ