Cecil Moore wrote:
Tam/WB2TT wrote:

What it really is is an impedance matching network. You adjust the
antenna tuner so that the transmitter sees 50 Ohms. If your SWR meter
is calibrated for 50 Ohms, that means an SWR of 1:1 (between the tuner
and the radio).


Yes, and that is a Z0-match to 50 ohms. What happens
at a Z0-match is wave cancellation of reflected waves
through destructive interference which redistributes
the reflected energy back toward the antenna in the
form of constructive interference energy that joins
the forward wave.

Correct, except for the part about destructive interference
redistributing reflected energy. Please note the absence of any such
claim in the cited (or any other) reference.

micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/waveinteractions/index.html


"... when two waves of equal amplitude and wavelength that are
180-degrees ... out of phase with each other meet, they are not actually
annihilated, ... All of the photon energy present in these waves must
somehow be recovered or redistributed in a new direction, according to
the law of energy conservation ... Instead, upon meeting, the photons
are redistributed to regions that permit constructive interference, so
the effect should be considered as a redistribution of light waves and
photon energy rather than the spontaneous construction or destruction of
light."

One addendum:
"Therefore, simple diagrams, such as the one illustrated in Figure 1,
should only be considered as tools that assist with the calculation of
light energy traveling in a specific direction."

The same holds true for the simplified explanation provided by the site.

The reason that the transmitter is protected is that
the Z0-match *causes* that redistribution of the reflected
energy back toward the antenna.

More to the point, the Z-match reflects energy back toward the antenna.

73, ac6xg