Gene Fuller, W4SZ wrote:
"The problem comes from the higher losses that occur in even the
"lossless" transmission line when operating at high voltages and
currents."

That`s right. Gene put quotes around "lossless".

The power output of the transmitter equals thaat taken by the load
inspite of hier indicated forward power. The difference is a power that
continues to circulate, much as baggage on an airport carrousel
continues to circulate until it is taken away.

Best regards, Richard Harrison, KB5WZI