I completely agree with Jim. I would add one other option, the N2PK VANA, if
you're into home building and can work with SMDs. I have an early version of
this and also a VNWA 3, which I have yet to fully acquaint myself with.
It's funny that I just today ran across an old brochure for the lab I used to
work in at Hughes Aircraft. There is a photo of me in "my" lab sitting in front
of an HP8510C Network Analyzer, that as I recall, cost in the neighborhood of a
quarter Megabuck and filled a good part of a four foot rack cabinet. The VNWA,
which fits in the palm of my hand, within its more limited frequency range, is
essentially its equal.
Dan's (AC6LA) programs are superb. The free stuff: "TLDetails" and "Zplots"
will go a long way toward educating someone new to transmission lines.
We live in amazing times. In my technical lifetime we've gone from drawing
reflection coefficient traces on a scope face with a grease pencil to this stuff.
Wes N7WS
On 3/30/2014 11:16 PM, Jim Brown wrote:
On 3/30/2014 7:37 PM, Mark Tellez wrote:
What is most important to me is accuracy, ease of use and of course giving me
all the info I will need to adjust my antenna.
Do you own, and have you studied (a LOT) the sections of the ARRL Handbook and
the ARRL Antenna Book on Transmission Lines and on the kinds of antennas that
you want to "adust?" If the answer is no, do that before you buy an analyzer
that will tell you things that you don't understand.
The AIM units are popular and highly advertised, sold by a reputable
distributor, and are quite powerful, but they are of little use to someone who
hasn't studied antennas and transmission lines a LOT. They are also expensive.
My favorite of this sort of analyzer is the VNWA 3e, designed by DG8SAQ, an EE
prof at a German university, and built and sold by a ham in the UK. It is more
powerful, and more convenient to use than the AIM units, and at about $700, is
half the cost of the comparable, but less capable, AIM 2180. It's also quite
well supported online by the designer, who also wrote the software. All of
these units work with a computer via the USB port to manage the measurement
and display and process the data. A nice advantage of the VNWA 3e is that it
gets power from the USB port. The AIM units need a power supply, which makes
it more complicated to drag them into the field.
All of these units may "swept frequency" measurements, and can write data
files of the data they have measured so that you use them in design programs
like Sim Smith, and AC6LA's excellent Excel spreadsheets.
That's the nigh end. The low end are boxes like the MFJ-259-series, the latest
version of which a C-model. The 259 has been ubiquitous for at least a decade
-- it's very portable, it does a lot if you've studied those ARRL books, it's
very portable (although it EATS batteries like an NFL lineman devours steaks)
and you don't cry nearly as long when you drop it off the tower.
In the middle are newer dedicated "boxes" like those you've listed, and
others. The more capable ones can do sweeps and generate data files, and they
are relatively portable (like the 259) but they are likely to be a LOT less
precise than the units that work with a computer.
Summary: None of these antenna analyzers will make your antenna work better,
but studying those ARRL books WILL. And you won't understand what the
analyzers are telling you if you haven't studied those books. And you can buy
the books for a third the cost of the least expensive analyzer!
73, Jim K9YC
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