John Kaufmann wrote:
> A some of you may know, the AIM4170 antenna/impedance analyzer was
> Immunity to RF overload appears to be quite good. I took the analyzer to
> a friend's QTH for antenna measurements. He lives very close to a 50 KW
> AM BC station. With a wideband scope we measured 0.4 V peak RF across the
> feedpoint of the antenna from the BC station. However, we had no trouble
> making good measurements from 160 to 10 meters. My friend's Autek
> analyzer completed folded up in the presence of the same interference.
> The manual for the AIM4170 indicates 2 V peak is the "damage" threshold
> for the device.
Depends on what "good" means. I am 6 miles from the nearest BC
station and the AIM4170 is useless measuring my 90 foot 160 meter
vertical. The manufacturer refuses to modify the software to allow a BCB
reject filter to be calibrated out, so I have a $500 paper weight. Even
if this software is written, I have to spend $200 on a BCB reject filter
to make it work.
> Another feature, which I find very useful and important, is an automated
> calibration procedure that compensates for the stray
> inductance/capacitance of measurement leads. Those of you who have tried
> to make measurements of high impedances at high frequencies can appreciate
> how important this is.
> Disclaimer: I have no affiliation with or commercial interest in the
> vendor. I am a very satisfied user and highly recommend this unit. It
> provides a lot of performance at a very reasonable price.
> 73, John W1FV
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