On Jun 13, 9:35*am, Cecil Moore wrote:
On Jun 12, 8:52*pm, Owen Duffy wrote:

If there was a valid Thevenin equivalent circuit for a transmitter (and
that is questionable), then you can not use that equivalent circuit to
make any inference about the internal dissipation of the source (the
transmitter in this case), or its efficiency. Nevertheless, I see people
trying to do this one way or another in the various threads here.

In his food-for-thought article on forward and reflected power, Roy
(w7el) says: "So we can model a 100 watt forward, 50 ohm nominal
transmitter as a 141.4 volt (100 * sqrt(2)) RMS voltage source in
series with a 50 ohm resistance." He goes on to calculate power
dissipation in the source resistor.
--
73, Cecil, w5dxp.com

And a mere two sentences back one find Roy writing:
"I make no claim that the model circuit represents what’s going on
inside the transmitter. For one thing, a real transmitter will
typically be more efficient than the model. However, if measurements
and observations are limited to the outside of the transmitter,
the model is very good (within the non-shutdown range). Although
a real transmitter won’t contain the model’s resistance as a
resistor, we will take a look at the model resistor’s dissipation
to see how it interacts with the “reverse” power."

Was your disingenuity deliberate?

....Keith