Keith Dysart wrote:
Please try again after adding 1 more wavelength of 450
Ohm line between the generator and the 75 Ohm line you
added. Kindly explain where the 'reflected power' on
this new section of 450 Ohm line goes.

It doesn't leave the 450 ohm line as long as the generator
sees 75 ohms as a load. Here is a similar example:

source---75 ohm line--+--1/2WL 450 ohm line---75 ohm load

Where does the reflected energy on the 450 ohm line go?
Since there is a 75 ohm Z0-match at point '+', it circulates
between the load and point '+'. Decrease the length of the
75 ohm line by one inch until it doesn't exist anymore.
The same conditions continue to exist all during that time.
The reflections at point '+' disappear in the process of
wave cancellation which is a type of permanent interference.

Now consider that the 75 ohm line can be one foot
long and everything is the same as the 1WL of 75
ohm line (except the delays).

This would be quite incorrect.

No, this would be 100% correct. One foot of 75 ohm coax
is enough to establish a 75 ohm environment. A 75 ohm
load on the source is enough to establish a 75 ohm
environment. Please see:

http://www.w2du.com/r3ch19a.pdf
--
73, Cecil http://www.w5dxp.com