Owen Duffy wrote:
Your FM HT is a classic case than can be adequately represented by a steady
state analysis. Your HT was operating into a load that increased its
dissipation, but there would be almost certainly be other mismatched loads
that would decrease its dissipation... but you wouldn't notice the event,
you would likely only remember the times the HT was too hot to handle.

If the constructive interference is toward the source,
it will run warm. If the constructive interference is
toward the antenna, the source will run cool. Antenna
tuners cause total destructive interference toward
the source and total constructive interference toward
the load. RF energy obeys the conservation of energy
principle.

I await the inevitable photon explanation.

None needed. Interference patterns work for voltages and
that's all one needs to figure out why the source is too
hot or cool. It's a no-brainer. If the energy is going
into the antenna and not being reflected, that energy
is not being dissipated in the source. If the energy is
not going into the antenna, it doesn't take a rocket
scientist to figure out where it must be going.
--
73, Cecil http://www.w5dxp.com