Topband: Chokes, et. al. - what is the attenuation ?

[Tom W8JI]

> A monoband current forcing balun doesn't require as much coax as you might 
> think.  The 1/4 wavelength of coax would probably be needed anyway, so the 
> only "extra" length is the 3/4 wavelength coax and thats only 35 feet of 
> RG-213 on 20 meters.
>
> http://www.qsl.net/i0jx/balun.pdf

Very interesting concept. Someone really thought that out, and it appears 
workable at first look.

It would probably make a great 1:1 single band VHF or UHF balun, unless I 
missed something.

I see it a little different for HF. While it would work (at least it appears 
correct to me), a current balun would maintain balance just as well, be 
wider bandwidth, cheaper, and have less loss. I think I'll stick with my 
large ferrite bead baluns for HF, but that sure looks good for VHF and up. I 
think it is a great idea for VHF/UHF, where beads won't work well and 3/4 
wave transmission lines are not physically long.

Thanks for posting that, it is an interesting concept.

73 Tom