Cecil Moore wrote:
Roger wrote:
I won't repeat that posting here, but please comment.

Will this source satisfy your needs? It is linear
and it prohibits reflected energy from reaching
the source making tracking energy rather simple.
I usually define it as a 50 ohm device but other
impedances could be chosen.

100w--1---2--
\ /
3
|
R

Thanks for alerting me to this device, which is real.

Thanks also for pointing out (in another posting) that the Norton source
is a constant current source.

But no, this will not do. The problem is that "We want to investigate a
1/2 wave length of transmission line, excited at one end. How soon is
stability reached?"

No doubt, past postings have not so clearly stated the scope of
investigation.

Unstated, and perhaps confusing, is the the power level must be limited
to some real value.

Also unstated, but reasonably assumed, is the understanding that the
exciting source would not be part of the circuit except as needed to
provide the excitation.

This last assumption was never achieved because the responders all
insisted that the source must be part of the investigation. It was
further insisted that the source invert the reflected waves with a -1
reflection factor. Had a +1 factor been acceptable, which is equivalent
to the reflection factor of an open circuit, the assumption would have
been realized.

Several responders discussed the Norton or Thévenin equivalent circuits.
These circuits assume steady state conditions, and are intended to be
replacements for groups of components. A very useful concept, but not
appropriate for startup excitation of a transmission line unless the
intent was to investigate the source AND transmission line as a system.

More later. I as still thinking about the "perfect power source".

73, Roger, W7WKB