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Old May 20th 11, 02:25 PM posted to rec.radio.amateur.antenna
Wimpie[_2_] Wimpie[_2_] is offline
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First recorded activity by RadioBanter: Mar 2008
Posts: 329
Default Transmitter Output Impedance

On 20 mayo, 14:42, Cecil Moore wrote:
On May 19, 5:22*pm, Wimpie wrote:

Many amateurs built and / or designed their own HF PA (and
other circuitry relevant to the hobby). Do you really think that they
all considered every component to be a transmission line?


You apparently have not comprehended what I am trying to say. When one
is designing a piece of equipment, whatever works, works. Please don't
confuse design/analysis techniques and rule-of-thumb shortcuts with
the underlying principles supporting the laws of physics. Enumerating
all the design techniques in the world does not tell us anything about
what is happening in reality to those photonic fields and waves that
necessarily must obey the laws of physics.

Even DC impulses travel at the speed of light. Electron drift velocity
is much, much slower than the speed of light. Everything EM is
photonic in nature. Photons must obey the laws of physics known to
exist for photons. There is simply no getting around that fact. All of
the magical thinking, hand-waving, design/analysis shortcuts, and
rules-of-thumb in the world are not going to change those facts of
physics.


Hello Cecil,

When one knows the physics well, one knows what to take into account
and what to left out, just to finish the job efficiently. It seems you
don't understand that principle. Is this some lack of understanding
physics?

Do you really believe that when designing an optical detector
(completely off-topic) I don't bother about noise due to quantisation?

If you do not understand those physical limitations (including. the
difference between the two IEEE definitions of impedance) you will
never understand what is actually happening in reality inside (or
outside of) an RF source. I don't know what else to say.
--
73, Cecil, w5dxp.com


Regarding PA's and IEEE definitions, I don't get paid for my
knowledge (if present?), but just for delivering what has been
agreed.

You introduced photons here; I think you may also introduce
thermodynamics of electrons as that may be of more importance at our
frequencies. I do not violate agreed laws of physics, but only leave
out higher order effects that are insignificant in my opinion.


Wim
PA3DJS
www.tetech.nl