Roger wrote:
To elaborate, the power (Pt) resident on the transmission line will always be
the sum of forward power and reflected power.

That statement is slightly misleading. The length of the transmission
line can be converted to time, e.g. one microsecond long. If the
forward power is 100 joules/sec and the reflected power is 50
joules/sec, the total energy in the one microsecond long transmission
line will be 100+50 = 150 microjoules. Energy is what is flowing in
the feedline and must be conserved, not power.

The technically correct way to say what you are trying to say is:
There is exactly the amount of energy resident in the transmission
line needed to support the steady-state forward and reflected power
readings. I realize that I am picking nits.
--
73, Cecil http://www.w5dxp.com