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Old March 9th 08, 10:07 PM posted to rec.radio.amateur.antenna
K7ITM K7ITM is offline
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First recorded activity by RadioBanter: Jul 2006
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Default The Rest of the Story

On Mar 8, 12:49 pm, Cecil Moore wrote:
....
Tom, you are the one who implied that coherency or
incoherency doesn't matter.


No, you're the one who inferred that from what I actually did say,
which is (in assorted different wordings) that we're dealing with a
linear system, and as such we can fully analyze it and indeed get MORE
insight into what's going on by using instantaneous voltages and
currents than we can in looking only at averaged powers. Indeed, in
setting up the analysis, it matters not a whit what relationship the
reverse wave has to the forward wave. There is neither a need nor an
advantage to special-case something like coherency; it all falls out
of the much more general analysis. There may be interesting things to
observe in the outcome of the analysis; that's a different issue.

Note that, as far as I've been able to determine, Michelson did not
have a coherent light source to shine into his interferometer, but
still he saw interference patterns. Perhaps he had invented lasers
but failed to tell the world about them, but I rather doubt it.
Carried to something more of an extreme, FTIRs tell you about the
spectral content of relatively broadband light, a few octaves, by
analyzing the interference pattern produced by a Michelson
interferometer. But the instruments and models I can reasonably apply
to our slow-as-molasses radio-frequency waves let me get even more
insights into what's going on.

As far as I can see, this is all in agreement with what Gene, Roger
and Keith, and perhaps some others I haven't been following, have been
saying in this thread, and what many others have said for years in
this group. If you get the idea that people aren't listening to you,
maybe it's because they've heard your story and see no advantage in it
over the more general analysis that's readily available.