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/
Paul, W9AC
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Jim Brown
Sent: Saturday, December 24, 2022 10:29 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Wireman W2DU Current Type Balun
On 12/24/2022 6:47 PM, Jim W7RY wrote:
> The 1:1 shown is exactly the same as Balun Designs. Except for the
housing.
Do you know that it's the same ferrite mix? That makes a huge difference,
and #31 the only one I've found that yields REPEATABLY good high Rs values
at HF. #43 and #52, which can provide high enough values, but they are much
higher Q than #31, so the wide mfg tolerances of all ferrite cores causes
every one to be different.
73, Jim K9YC
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