[RFI] RFI clip-on probe?

[Wiley Sanders]

Ian G3SEK wrote "Build or buy a clip-on RF current probe ..."

Sounds neat - how is the probe constructed? Do you make a loop around the 
conductor, similar to the high-amp AC ammeters except with a loop or two of wire?

I have an ANC-4, one of those thingys that amplifies noise and reverses the 
phase to null it out. This loop concept is one I have tried by connecting the 
"noise sense" antenna by wrapping the 2 meters or so of insulated wire that 
came with the unit around the rig AC power cord, both as a loop and strung out 
lengthwise along the power cord. It has been pretty effective against the 
hideously loud RF from the giant halogen dimmer lamp upstairs but no so 
effective against the neighborhood power line noise that I believe is being 
conducted into the house and reradiated via the house wiring. This loop would 
be good at picking up common mode RFI from the AC power cord but not so good 
at picking up differential mode RFI - maybe I should split the power cord and 
loop the sense antenna around only one of the conductors?

-wiley kf6iiu