[TowerTalk] Analyzers

[Brian Machesney]

If you're putting filters between the device under test and the analyzer and
need a correct impedance measurement, don't forget to account for the
transfer function of the filter. I had W3NQN build a custom filter about ten
years ago that had transfer zeros at the frequencies of two local AM
stations. I wrote a spreadsheet to perform ABCD matrix operations that
"backed out" the filter (and the measured characteristics of the
transmission line) to be sure I got readings that properly represented the
bahavior at the feedpoint.

Brian K1LI


On 6/1/08, Denis Coolican <coolican at telus.net> wrote:
>
> Autek Research handle the VA1 antenna analyzer which goes up to 30 Mhz.  It
> can measure the + or - j values and indicate such.   I use a 1.8Mhz high
> pass in front of it and in front of the MFJ 259B.  The VA1 sure is nice and
> compact.  The MFJ you can still send out to have repaired if you have to.
>
> The AIM 4160 looks good and probably comes the closest to a real General
> Radio  RF impedance bridge from the past.
>
> Denis Ve6aq
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>