[TowerTalk] Ferrite, or choke baluns?

[Jim Brown]

On Fri, 18 Jan 2008 07:47:16 -0500, Roger (K8RI) wrote:

>Some one used to make a "choke Balun. I belive it was just a series of 
>ferrite beads over coax inside PVC pipe, but they seemed to work well.  As 
I 
>recall they covered 1.8 through the 50 MHz bands.

"Cover" is quite loose. They are ADVERTISED to work on all bands, but they 
don't work very well, and they are very sensitive to feedline length. 

>Any one know who made them and if they are still available, or if not how 
>many beads of what mix over what size coax? 

For about $20 in toroids, you can BUILD a choke balun that is VASTLY 
superior to anything you can buy for less than $100. The only choke balun 
worth buying is made by DX Engineering, and they are big, heavy, and cost 
about $130. They are EXCELLENT, but FAR too heavy to use at the feedpoint of 
my dipole. :) 

See http://audiosystemsgroup.com/RFI-Ham.pdf 

and 

http://audiosystemsgroup.com/NCCC-CoaxChokesPPT.pdf

73,

Jim Brown K9YC