Keith Dysart wrote:
You are trying too hard. Even your problem statement said
"no circulator". So I offer a simple example of such a
generator: a voltage source connected by a 450 Ohm resistor
to the output terminal. Voila: a generator with 450 Ohm
output impedance.

The generator is an *active dynamic source*. It does
not have a 450 ohm output impedance just because you
install a 450 ohm resistor. Just as soon as reflected
waves are allowed to reach the source, the source
impedance dynamically shifts away from the 450 ohm
value.
--
73, Cecil http://www.w5dxp.com