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Old April 7th 07, 07:44 PM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 3,521
Default Constructive interference in radiowave propagation

Owen Duffy wrote:
Walt, this seems inconsistent with the approach that I believe you seem
to use in analysing waves in transmission lines where you seem to want to
not only deal with the forward and reverse waves separately (ie to not
collapse them to a resultant V/I ratio at a point), but to deal with
multiply reflected waves travelling in the forward and reverse direction
(which is only necessary in the transient state).


I think what Walt is trying to do is explain that there is
no interference at power up. As the reflections build up,
the interference builds up, until there is total
destructive interference toward the source during steady-
state and total constructive interference toward the load.
Without interference, a Z0-match would not be possible.

The principle of superposition gives us permission to
analyze the forward and reverse separately and collapse
them to a resultant V/I ratio later. If one wants
to use the simplified mashed-potatoes approach, that is
OK since the results are the same in either case.
--
73, Cecil http://www.w5dxp.com