[TowerTalk] Baluns/tutorial/notes.

[jimlux]

Steve Hunt wrote:
> Jim,
> 
> Can you say something more about what you see as the failings of the AIM.
> 
> I was impressed by how my AIM handled high impedances. If I calibrate it 
> carefully, and then measure a 10k resistor, the AIM predicts a parallel 
> equivalent of 10k//0.2pF with less than 5% variation anywhere in the 
> range 1-30MHz.
> 
> 73,
> Steve G3TXQ
> 
> Jim Brown wrote:
>> High impedance measurement on a traditional vector analyzer can be 
>> tricky, as noted in my section on measurement. :) Reflection-based 
>> measurements yield considerable error, because the unknown Z is too 
>> far from the 50 ohm circuit Z. HP addresses this in one of their app 
>> notes on Z measurement. That's the failing of the AIM unit. 
>>   
> 


Steve,
what about a high reactive impedance.

Mostly, the problems I've had with this kind of thing have to do with 
fixturing and/or calibrating the fixture out.  I was trying to measure 
the Z of traps, and never did get a good fixture scheme worked out. It's 
not like you can just take a couple banana plug clipleads..  I finally 
decided to remain ignorant of the electrical properties of the traps in 
a 6-BTV.