[TenTec] 4229 Tuner Balun Replacement?

[Jim Brown]

On 11/14/2010 4:22 PM, Dr. Gerald N. Johnson wrote:
>> 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.
> Or if the feed line isn't perpendicular to the radiator and so gets
> coupled to the radiator beyond the choke.

That's the function of the additional choke as egg insulator -- to break 
the feedline into lengths (from a common mode point of view) where very 
little current can flow.

73, Jim K9YC