Forgot to mention that a very powerful attribute of the software-based VNAs
is that in many instances, accurate Z measurements can be made at the rig
end of a coaxial cable and you don't need to know anything about the type of
coax, nor its length. During Open/Short/Load (OSL) calibration, the loads
are moved to the antenna end of the line. The VNA software will then
calculate loss, distance, and velocity factor. From that point forward,
complex Z of the load can be measured at the rig end of the line.
Paul, W9AC
----- Original Message -----
From: "Paul Christensen" <w9ac@arrl.net>
To: <towertalk@contesting.com>
Sent: Tuesday, July 17, 2012 4:34 PM
Subject: Re: [TowerTalk] Antenna analyzer
>> What are the best antenna analyzers for the Ham market? I'm referring
>> to both portable and computer based. I have not found the MFJ line to
>> be satisfactory. I have used one for some years.
>
> For PC-based, any of the W5BIG analyzers sold through Array Solutions are
> good candidates. If you don't need VHF+ capabilities, the N2PK VNA is
> excellent. Mine was supplied by M0WWA who builds them to order. The VNWA
> seems to be popular and goes well up into the UHF range.
>
> For portable and up the tower, I would look at the RigExpert VNA series.
> If you do any 160m antenna measuring, the PC-based VNA type analyzers will
> do a good job of rejecting AM BC interference. Here's a link to a N2PK
> VNA sweep I took of N4NN's Marconi "T" after construction last December.
> Notice the "blips" on the resistance (Rs) curve. The VNA software almost
> completely ignores two very strong AM broadcast stations at 1320, 1400,
> 1460, and 1530 kHz. All four stations are located just a few miles to the
> south of the QTH.
>
> http://72.52.250.47/images/N4NN.jpg
>
> Paul, W9AC
>
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