On 11/14/2010 11:11 AM, Dr. Gerald N. Johnson wrote:
> and they might not prevent feedline radiation and reception.
There are two causes of feedline radiation/reception -- common mode 
current and conductor spacing. A common mode choke AT THE FEEDPOINT can 
essentially kill the radiation due to common mode current unless the 
feedline is some multiple of a half wave, in which case an additional 
choke placed along the line to act as an "egg insulator" to make it less 
than a half wave would kill the remaining current.
The choke will, of course, have no effect on radiation due to spacing, 
which results from the differential signal.
73, Jim K9YC
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