[TowerTalk] Wireman W2DU Current Type Balun

[Máximo EA1DDO_HK1H]

Hi Jim,

Happy Christmas.

Regarding the test jig, Are you still using that one made of Teflon board with short coax tails to the D8SAQ ?

Thanks

73, 
Máximo EA1DDO
www.EA1DDO.es





 





-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Jim Brown
Sent: domingo, 25 de diciembre de 2022 10:05
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Wireman W2DU Current Type Balun

Hi Paul,

I made S21 measurements using a test jig quite similar to Steve's. His measurement technique seemed quite good. The (major) shortcoming of his work is that he measured only chokes on only a few cores, failing to understand the contribution of production tolerances to reproducible designs.

A limitation on the precision of my data is that my fixture had to allow measurement of many hundreds of chokes on many cores, not a few.

73, Jim K9YC

  On 12/25/2022 12:02 AM, Paul Christensen wrote:
> Jim (K9YC),
> 
> When making Rs measurements are you using the S11 or S21 method?  
> Steve, G3TXQ was an advocate of S21 while Owen, VK2OMD claims S11 
> results in better accuracy with high Rs values.
> 
> I've been using S21 with G3TXQ's VNA adapter on a PC board.  It's 
> shown at the bottom of the page in the link below:
> 
> http://www.karinya.net/g3txq/chokes/



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