At 05:51 PM 11/20/2008, Jim Brown wrote:
>On Thu, 20 Nov 2008 16:18:23 -0500, Jim Monahan wrote:
>
> >The kits listed below have worked very well
> >for me on my beverages:
>
> >http://www.antennex.com/palomar/balun_kits.htm
>
>These are vastly inferior to the chokes I've recommended. That is,
>my coaxial choke designs will provide MUCH greater isolation between
>the Beverage and the coax.
You might also take a look at the two-choke design in recent editions of
ON4UN's book (the one that has the shield grounded between two strings of
beads about 15 feet from the matching transformer, with the shield at the
transformer floated). See, for example, Fig 7-88 on page 7-60 of the 4th
edition. I do not understand the theory, which is explained in the book,
but W1HIS, who also has done extensive work on chokes for noise reduction,
says it will work as advertised, making the most out of your choke
impedances. I use this design with a K9AY loop, which has a very low
output level, and so is very much affected by shield pickup.
73, Pete N4ZR
73, Pete N4ZR
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