Dave wrote:
try to look at it this way. when you look at the forward and reflected
waves separately it is intuitively obvious how the power calculation shows
the flow along the line with each wave.

This is a very old equation:

Pnet = PLoad = Pfor - Pref = Vfor*Ifor - Vref*Iref

For a pure standing wave it reduces to:

Pnet = Pfor - Pref = 0 or |Pfor| = |Pref|

There is zero net power transfered in a standing wave
so Vtot*Itot*cos(A) = ZERO *at every point* along a
lossless line containing pure standing waves, not just
at the Vtot=0 and Itot=0 points, but *everywhere*.
--
73, Cecil http://www.w5dxp.com