Keith Dysart wrote:
So why did I think otherwise?

Because you have been told by others that I was superposing
powers. It was a false malicious statement.

But them I am confused with your ready acceptance of
Ptot = P1 + P2 +/- Pinterference

If it is good enough for Eugene Hecht, it is good
enough for me. That is essentially the irradiance
from optical physics.

Given a P1 that actually exists and a P2 that actually
exists it seems to me that Ptot must equal P1 + P2.

No, that is superposition of powers, something that is
not valid. The only time that Ptot = P1 + P2 is when
the phase angle between the voltage is 90 degrees and
the interference term is zero.

Anything else would fail to satisfy the principle of
conservation of energy.

No, Ptot = P1 + P2 violates the conservation of principle
if the phase angle between V1 and V2 is not 90 degrees.

To make the expression work, +/-Pinterference must
be creating or destroying energy.

No, there are two Ptotal's, one in each direction in
a transmission line. If a certain value of destructive
interference exists in one direction then an absolutely
equal value of constructive interference has to exist
in the opposite direction in the transmission line.
Since destructive interference = constructive interference,
no energy is created or destroyed.

All this is explained in my energy article.

Can you elaborate on how +/-Pinterferance creates or
destroys energy while still conserving energy?

Transmission line energy is neither created or destroyed.
What is lost in one direction is gained in the
opposite direction. If reflected energy is eliminated
toward the source, it must show up in the forward wave
toward the load. I cannot explain it any better than
these web pages.

http://micro.magnet.fsu.edu/primer/j...ons/index.html

http://www.mellesgriot.com/products/optics/oc_2_1.htm
--
73, Cecil http://www.w5dxp.com