Topband: Location of common mode chokes

[Rick Kiessig]

In addition to placing a common mode choke at the feedpoint of the antenna,
have you also found it useful to place one at the rig?  

 

I have a vertical with 135 feet of feed line, and I'm trying to do what I
can to clean up receive noise and the radiation pattern.  I attached the
shield of the coax to ground just outside the shack a while back when I
noticed almost 1 volt of AC on the line.  That removed the AC, but it seems
like common mode current might still be an issue.

 

73, Rick ZL2HAM