Cecil, W5DXP wrote:
"What causes the match? The cancellation of reflections."

This is like Abbot and Costello. You got it! Who`s on first!

You have a source which only delivers energy at a certain volts to amps
ratio, period!

You have a load which only accepts energy at a certain volts to amps
ratio, period!

When the above ratios are in fact identical there is no problem. When
the above ratios are different something has to give and it isn`t either
ratio, Zo or ZL. Instead, the load takes what the source can deliver and
rejects the surplus volts or amps whichever is the case, as are created
by ZL, and the limited deliverability created by the Zo. The surplus
generates a reflected wave as Cunningham recounted with his description
of missing inductance and capacitance in the missinng continuation of
the transmission line (A short on the line vitiates the capacitance
etc.). The explanation is logical and I recommend his broadcast antenna
book.

What`s not to understand about matching? When the load is not matched,
you add the incremental receptivity required to take the surplus current
or voltage at the load, so that the load, and the stub in Terman`s
example, are a perfect match and there is no longer any surplus to be
reflected. The impedance of the load has been adjusted, by the addition
of a stub in Terman`s example, to Zo. Terman says the wave from the stub
cancels the wave from the mismatched load. No doubt a shorted stub makes
a reflection. The reflected volts from the stub are exactly equal and
opposite to the reflected surplus volts from the load at the junction,
and Terman says there is no reflection toward the generator.

I never won an argument with Terman, though I tried. I believe there is
no reflection past the stub back toward the generator. If so, and it
certainly is so, I`ve put those stubs out at the antenna myself and they
create a match when adjusted properly, the energy on a lossless line
will be the same at the generator and anywhere on lhe line. It`s flat.

Best regards, Richard Harrison, KB5WZI