Richard Fry wrote:
"Roy Lewallen" wrote:
All the power produced by the transmitter arrives at the antenna
less whatever is lost as heat in the transmission line.

How about a case of a non-resonant transmission line whose Zo equals the
load Z except for a discrete mismatch somewhere in the line?
Reflections from that mismatch will be dissipated in the reverse port
termination of a circulator installed at the input of the line. Clearly
not all of the power available at the output of the circulator arrived
at the antenna (less line loss).

Certainly if you install a resistor in the line, whether connected to a
circulator or not, some of the power leaving the transmitter won't make
it to the load. I was assuming when I made my statement that no such
objects were placed in the transmission line, and would hope this
condition would be obvious to most readers.

..Unless the line is perfectly matched, there will be repeating points
of high current and of high voltage. Depending on the nature of the
conductor and insulator, either or both of these can cause localized
heating. In the example you gave, the damage is almost certainly
caused by high current rather than high voltage. ...

I agree, and misunderstood your original post.

Roy Lewallen, W7EL