On Fri, 08 Oct 2010 11:14:13 -0400, John Ferrell wrote:

I have been faithfully using a coil of coax as a common mode choke for a
while without any idea if it is really doing any thing.

Googling turns up more url's than I can follow. I would appreciate any
suggestions as to how might measure the effects of the common mode
choke. 30 to 17 meters is my favored range of operation. I have a pretty
well equipted shack.
John Ferrell W8CCW

I have had some success with short pieces of copper tubing slipped over
coax. however, I have no way of checking it to measure how effective this
is