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Old December 24th 07, 03:00 AM posted to rec.radio.amateur.antenna
Roy Lewallen Roy Lewallen is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 1,374
Default Standing-Wave Current vs Traveling-Wave Current

Hi Walt,

I'm a little confused here. I hope you can straighten me out.

Walter Maxwell wrote:

It appears to me that even with all the successive posts on the subject of power in the standing wave, you all
seem to be missing the ingredient that proves why there is no useable power in the standing wave. It is
because the current and voltage in the standing wave are 90° out of phase. Multiplying E x I under this
condition results in zero power.


I've always regarded a "standing wave" as being a description of the
envelope caused by the interference between forward and reverse
traveling waves. But you're saying there are currents and voltages "in"
the standing wave. Are you referring to the total current and voltage at
any point along the line? If so, why are they always in quadrature?
Certainly, the total V and I are in quadrature if the line is terminated
by an open, short, or purely reactive load. But not in any other case.
Or do you regard a line as having a "standing wave" with its own voltage
and current which are different from the total V and I? If so, how do
you define a "standing wave"? Are there separate equations for "standing
wave" V and I that are different than for total V and I?

. . .


Roy Lewallen, W7EL