[TowerTalk] Antenna Analyzer Suggestions Solicited

[Jim Brown]

On Thu, 05 Mar 2009 20:47:38 -0800, jimlux wrote:

>Hmmm. just how much error would you get from measuring a choke (compared 
>to, say, a Agilent VNA).. how much is that from "fixture" issues.  The 
>dynamic range is pretty good on the TenTec TAPR box (not what the state 
>of the art Agilent boxes do, but probably comparable to an 8510-ish system)

>From my experience, quite a bit with a high impedance choke (in the 5K ohms 
range). That's AWFULLY far from 50 ohms. Now, a VNA could be made to work 
putting the choke in series between the two ports, but my TAPR doesn't get 
anywhere near that either.  I DID get good data doing that with an HP VNA 
that K6TD has. 

How much? With a choke like 14 turns on a #61 toroid, the resonant frequency 
can be wrong by a factor of 2:1.  

73,

Jim K9YC