[TowerTalk] homebrew 1:1 current balun

[Jim Lux]

On 11/30/15 9:17 AM, Jamie Tolbert wrote:
> What tpe beads do I need, 43 or 73? length? 4 ft, 100 beads seems awfully long.....
>
> ____________
I use 31 mix for this kind of choke application.

what is your operating frequency?

http://audiosystemsgroup.com/NCDXACoaxChokesPPT.pdf
see pages 22-25
73 is better in general, 43 is ok for low frequencies
31 isn't great for bead baluns..


Have you considered using a 2.4" toroid core(s) and running multiple 
turns of the coax through it.  I can get about 10-12 turns of 1/4" 
diameter coax (RG58 type) through those cores. I think you can get 3-5 
turns of 0.405" coax (RG213 type) through it.

There's a fairly decent cookbook for this kind of thing, with all the 
measurements on actual chokes, etc. in Chapter 7 of 
http://www.audiosystemsgroup.com/RFI-Ham.pdf