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Old October 24th 08, 12:33 PM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 3,521
Default Automatic tuner range

Owen Duffy wrote:
Where an impedance range is loosely specified as you quote (dimensioned in
ohms without identification of the R and X parts), and in the absence of
applicable frequency constraints and loss figures, I think you can safely
disregard the information as unprovable advertising hype.

It is intended to look technical, something to impress the new wave of hams
who don't have the understanding, and not enough to reliably determine the
suitability of the ATU to a specific application.


The matching range of a typical tuner can be estimated
by playing with the simulated tuner at:
http://fermi.la.asu.edu/w9cf/tuner/tuner.html
Select the frequency and load needing to be matched,
click auto, and see if the tuner can match it.

I wonder if Kevin would be interested in making the
tuner's CLC values user specifiable?

I have modeled tuners with Microsmith (an old DOS
program) and varied the C1, L, C2 values while watching
the trace on the Smith Chart. Given all possible
combination of CLC values, the result would be the
matching envelope of the tuner at a specified frequency.

What would be nice is a program that would automatically
plot the tuner's matching envelope on a Smith Chart given
the input parameters.
--
73, Cecil http://www.w5dxp.com