[TowerTalk] Measuring Common Mode Choke with Anritsu VNA

Steve Hunt steve at karinya.net
Fri Jan 5 05:30:33 EST 2018

Measuring high-Z chokes accurately is challenging, and it's easy to 
become obsessive about this stuff. I know because I'm probably one of 
the worst offenders :)

But then I ask myself:: if an uncompensated 0.5pF jig capacitance, or 
uncompensated jig leads 1 inch long, cause an error in the choke 
measurement that is operationally significant, variations in choke 
installation method will likely have the same effect and more. On top of 
that we have to remember the tolerance in ferrite characteristics - 
variously quoted as 25%. So why strive for measurement accuracy that has 
little direct relevance to most real-world installations?

Steve G3TXQ

On 03/01/2018 12:54, Wes Stewart wrote:
> In my opinion, and with my equipment, a two-port through measurement 
> is probably the better method.  That said there a lot of folks with 
> one-port measurement equipment who can make "good enough" measurements 
> on common-mode chokes.

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