Re: antenna tuners in general


ussv dharma
 

out of habit I use wording that describes the incident or problem as opposed to technical terms. Many of the people reading these posts online are new to electronics and I know that us old elmers (got license in 1952) know what is going on. I want it xtal clear for the new comers.....that being said, you are 100% correct in your comments.

If you don't change direction you WILL arrive exactly where you're headed!!
 
MSGT. Susan Meckley, USA (Ret.)
W7KFI  & AFZ4SM
 

--------------------------------------------

On Tue, 8/7/18, Nate Bargmann <n0nb@n0nb.us> wrote:

Subject: Re: [4SQRP] antenna tuners in general
To: main@4SQRP.groups.io
Date: Tuesday, August 7, 2018, 7:05 PM

* 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: http://www.n0nb.us GPG key: D55A8819 
GitHub: N0NB



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