Re: antenna tuners in general

J.K. Wright

AMEN!  Did a presentation this spring at our ham club on Maxwell's papers and teachings. He debunks a lot of commonly believed yarns about tuners, reflected power, swr.......
Jerry, NK2C

On Tue, Aug 7, 2018, 7:05 PM Nate Bargmann <n0nb@...> wrote:
* On 2018 07 Aug 16:01 -0500, ussv dharma via Groups.Io wrote:
> One must remember, an antenna tuner only fools the radio into
> believing there is a 50 ohm antenna....the tuner does not change
> anything about the antenna or coax feeding it.

Please, with all due respect, Susan, let's not use "fool" or "believe"
when discussing conjugate matching.  The match is real.  The 50 ohm
resistive load presented to the transmitter byt the tuner is real.  You
are correct that nothing changes on the line between the tuner and
antenna--a Wattmeter placed after the tuner will bear this out.  In
fact, you will see the result of the conjugate match as increased
forward power which is the original reflected power added to the
incident forward wave.  Except for line attenuation and the increased
attenuation due to SWR, all power is radiated.

Impedance matching is employed in all parts of a radio.  I've yet to
read a serious text that discusses impedance matching that describes
matching in anything but technical terms or complex numbers to describe
the impedance involved.

An excellent reference on the topic is one of the thee editions of
Reflections by Walt Maxwell, W2DU SK, if they can be found.  Reflections
III was published by CQ Communications several years ago.  I'm unsure if
it is still in print.

Walt wrote a series of articles in the '70s that were printed in QST.
ARRL members should be able to locate them in the QST archive.  Those
articles formed the basis of the Reflections books.  Walt was an
accomplished engineer, yet the books are written "for the rest of us"
and contain a wealth of information.

72, Nate


"The optimist proclaims that we live in the best of all
possible worlds.  The pessimist fears this is true."

Web:  GPG key: D55A8819  GitHub: N0NB

Join to automatically receive all group messages.