[Elecraft] Common mode chokes

[Jim Brown]

On Tue,8/9/2016 1:56 PM, MaverickNH wrote:
> Just wondering - short of +/- RF Burns and Audible Noice, can one readily
> detect/measure Common Mode Current on a coax antenna feedline?

Yes. A calibrated RF current probe coupled to the outside of the coax 
can easily measure common mode current.  Here are a couple of easy ways 
to do it.

http://www.ifwtech.co.uk/g3sek/clamp-on/clamp-on.htm

Note that because the coax is acting as part of an antenna for common 
mode current, the current will vary along the line just as it would for 
any other antenna. For example, the coax a simple wire dipole in an 
earth-based station acts as a wire connected between the shield side of 
the dipole and ground, with the length of the wire equal to the physical 
length of the coax, and oriented in space as the actual coax is routed.

73, Jim K9YC