[TowerTalk] One off balun question

Jim Brown jim at audiosystemsgroup.com
Sat Nov 1 02:17:24 EDT 2014


On 10/31/2014 9:43 AM, Steve Hunt wrote:
> I measured the choke resonant frequency using a 2-port VNA S21 
> measurement. 

I have yet to find a swept antenna analyzer or VNA that will measure 
chokes correctly above about 10 MHz, and I've tried that the the DG8SAQ 
VNWA. I don't have access to the good (and very expensive) HP Impedance 
Meters that Fair-Rite uses.

Other than that, the only data I trust is the scalar data (magnitude 
only) using the method documented on my website.Every choke I've 
measured with one of those analyzers came out MUCH lower in frequency, 
but my data matches Fair-Rite's data with reasonable accuracy.

73, Jim K9YC



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