I've been watching the mail on this and I'm surprised that no-one has stated
the fact that the input impedance of these amplifiers is not constant. Does
anyone really believe that the input impedance of a 4-1000A is 105 ohms
(always, invariant)? It probably varies +/- 20 ohms or so dependent on
frequency, drive level, etc. This is why we use low Q and a circuit that
translates 50 ohms to what is the anticipated average value of the input
impedance.
'nuff said.
Wayne N1WR
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