[Amps] Autotuners in Amps

[Wayne Rogers]

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