On Sun, 24 Aug 2003 08:40:44 -0400, wrote:

For the power sine wave, though the fact that a minus times a minus is a
plus results in 2x the voltage frequency, dP/dt=0 at maxima.

Alternatively, from amplitude modulation, the product of two sine waves
produces a sum and difference frequency. When the two sine waves have
the
same frequency (as they due for the voltage and current contributing to
the power), the result is a double frequency sine wave and a 0 frequency
difference which is the DC or average power.


Hi Keith,

The two statements above are in not about the same thing within the
context of the subject.

The products of two sine waves as you describe are non-linear and are
not found on the Smith Chart, nor in the transmission line. [Except
insofar as it is forced deliberately (and that has yet to be revealed
by any correspondent), or through negligence of line maintenance with
corrosion products and dissimilar metals interfaced.]

73's
Richard Clark, KB7QHC