I'm not sure what the Vectronics thing does, but I'm sure it is
mostly a software change and manual. What was done is beyond
me, but I'll try to find out.
> It invites you to calculate by saying "the Magnitude of the impedance
> [Z) is the square root of the addition of square of the resistance (R)
> and the Reactance (X). By considering the definition of Z and by
> adjusting the TUNE knob until the lowest SWR reading is obtained, it
> is possible to read the antenna's pure reactance." So I guess
Hmmm. I don't know what someone was trying to say there.
> I understand the MFJ 259B will tell you the reactance (X) and the
> Phase (+j or -j).
You get the individual amounts, but it does not pretend to know!
Most other analyzers that claim to give the sign of reactance. They
mostly make a guess.
If you have a quarter, flip it and call heads inductive and tails
capacitive. It will be as good as the displayed sign when you are on
an antenna with most analyzers.
> Conclusion: The $149 Vectronics model is not an MFJ 259B. Sorry to
> break the bad news. However, it looks like it would be a big help
> adjusting antenna length, tuning stubs, finding shorts and opens,
> measuring velocity factor and cable loss, testing baluns, measuring a
> capacitor or inductor, and using as a grid dip meter or frequency
> counter.
Analyzers make poor grid dip meters. The rest they can do pretty
well. Anything the 259B can do, you can do with a calculator and
what this sounds like it tells you. The 259B just does all the fancy
stuff in software.
I like the 259B, because I can barely add and subtract numbers
more than ten without a calculator. And I know how to get the
sign....I just add a T connector and through a cap or inductor
across the open port to see if Z increases or decreases.
73, Tom W8JI
w8ji@contesting.com
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