[TowerTalk] Speaking of baluns

[Kevin Normoyle]

O
>> http://www.balundesigns.com/servlet/the-98/isolation-choke-balun-common/Detail
>>      
> Interesting. This looks like a #61 or #67 Fair-Rite material, or something like
> it. A rather poor choice for common mode chokes. To understand why, see my
> tutorial. Also, the AIM analyzer is known to have significant measurement error
> when measuring high-Q chokes like this. The actual resonance is probably around
> 18 MHz, not 8 MHz.
>
> 73,
>
> Jim K9YC
>    

Jim, I think you're unfairly judging the products? (I'm not sure why 
that link was presented as an example)

That link above is not his only offering, and each offering has 
differences. I think it's unfair to judge the product line from that 
one. It's his offering for use with ATU. He calls it "1:1 ATU Current 
Balun 1-35Mhz 5km #1114"

  He uses different mixes in different baluns. He offered his assessment 
of why that design is optimized for "Primary use is with an antenna 
tuner and a shortened multiband dipole fed with ladder line. " on that 
page. I guess one can argue with that.

I think from your point of view, a fairer assessment would be to look at 
his  "1:1 Balun 1.5 - 54 Mhz 5kw - #1115"
here (and this isn't his best, it's just
http://www.balundesigns.com/servlet/the-32/balun-designs-baluns-1-cln-1/Detail

His two sweeps are on that page, but the choking impedance is here directly
http://www.balundesigns.com/catalog/1-1%205kw%20Choking%20Impedance.jpg

While he doesn't name the mix, he says "Special mix toroid with low 
permeability"

I have a couple of the 1115's.

If you want to evaluate his "best shot" it's this one. It has two 
stacked cores (for $78.95)
http://www.balundesigns.com/servlet/the-63/balun-designs-1-cln-1-Isolation/Detail

The scan is here
http://www.balundesigns.com/catalog/1-1%20Stack%20Choke%20Imped.jpg

Again the mix isn't mentioned. But wouldn't you agree those are better?

-kevin
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