Hi Mike
I have the VA-1 and the AEA HF-CIA analyzers. I use them both,
but they don't tell the same story if you get very far from a
low swr situation. Once you get over about a 4:1 swr, the accuracy
goes somewhere else :-)
I figured this out from building matching networks designed on a
Smith Chart program, WinSmith. Great program, by the way. The
resulting networks didn't work, and the only thing I could attribute
it to was Garbage In-Garbage Out. WinSmith relies on reasonably accurate
R and jX info from the analyzers. So, since the networks were done
rather meticulously, I had to assume the design was faulty due to
bad input data.
This was true with both analyzers. At low swrs, they agree close
enough for ham work, but you still have to be willing to tweak adjustments.
I've had my VA-1 for about 7 years, at least, and the HF-CIA for about
6 years. Since neither tells the whole truth, it is valuable to be able
to play one off against the other. I'd like to have the use of an
MFJ unit for a while for comparison to see where it is strong, and
where it falls down.
73, Bob N6WG
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