I was with you on your first two paragraphs, but when I read the following
statement, it was time to ask for clarification:
> voltage at the tuner output. This voltage will be delivered back to
> the tuner input through the tuner components. The voltage delivered
> back to the tuner input will be the negative of the initial reflected
> voltage at the tuner input causing a complete cancellation of the
> initial reflection. Hence, the steady state 1.0:1 VSWR.
Let's not confuse the application of the following added elements, all of
which contribute to what is being discussed here: Voltage on the
transmission line, current on the transmission line, the forward wave, the
reflected wave, and the phase relationship between voltage and current on
the transmission line.
What I don't understand is your application of the term "voltage delivered
back to the tuner input," and "ALL of the voltage will not be re-reflected."
The "wave" is moving and reflecting, not the voltage. The
antenna-to-transmission line mismatch creates a reflected wave, not a
reflected voltage. True, the reflected wave's voltage will be 180-degrees
out of phase with the reflected current. From your statement above, how are
we getting to a 1:1 based on your fourth paragraph?
-Paul, W9AC
>
> The difference between this discussion and that of Walt Maxwell's is
> that Walt does not start by considering the initial state of the
> tuner. He immediately "assumes" that all of the transmitter power is
> delivered through the tuner, some is reflected by the antenna and then
> ALL is re-reflected at the tuner output. His initial assumption may
> support his conclusion but it does not accurately describe the
> operation of the tuner, nor all of the voltage reflections and
> cancellations that occur. With a lossless transmission line between
> the tuner and antenna his results are numerically correct, however, I
> am uncertain if this would be true when considering a case with
> transmission line attenuation.
>
> In any event, even considering the transmission line losses, the
> matched antenna will radiate more steady state power than the
> mismatched antenna and tuner. Remember that with the tuner, the
> reflections from the antenna must travel the transmission line twice
> before arriving back at the antenna.
>
> Which "works" better - matched antenna or mismatched antenna/tuner?
> The answer to this question requires a much more involved analysis.
> In order to "work", the transmit system only needs to provide a
> useable signal level at the receive site. In many cases, both will
> "work" quite well.
>
> 73, Steve, VE9SRB
>
>
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: [TowerTalk] Mismatch Loss and Tuners
>Author: kn6di@groupone.net
>Organization: Global Pack & Mail at InterNet
To: <towertalk@contesting.com>
>Date: 8/24/98 10:22 PM
>
>
>Wouldn't be great if people could talk in plain english and discuss this
thread
>in a straight forward manner instead of every one trying to get the last
piece
>of fly S--- out of the black pepper.
>It would be nice for a plain statement of facts of what works and does not
work.
>As we know no 2 antennas work the same because the conditions are not/never
the
>same. This could go on until cycle 30 at least.
>Hank KN6DI
>
>
>J
>
>
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>
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