On May 4, 10:47*am, Wimpie wrote:
Basically, it doesn't matter what is inside the box. It can be fully
characterized by its impedance versus frequency (small signal
approach).

If what is inside the box doesn't matter, why waste time trying to
measure what is inside the RF amp box? What can be "fully
characterized" is the box's relationship to everything outside of the
box. Exactly what is inside the box cannot be ascertained at all while
we handicap ourselves with a blinders. When we actually look inside an
RF amp, we find active non-linear devices upon which we all have been
warned about trying to use linear assumptions.

It doesn't matter what is inside the box when *conditions outside of
the box* are being considered. EE201. What is inside the box matters
considerably for *conditions inside the box*. For instance, replacing
a 50 ohm dipole with a 50 ohm lumped circuit doesn't change things
between the load and the source. But it causes an almost infinite
change from the load out to the rest of reality.

Anything else I could say on this subject would be repetition.
--
73, Cecil, w5dxp.com
"Halitosis is better than no breath at all.", Don, KE6AJH/SK