I received a number of replies to my question about figuring impedances from
known values of a pi-network, and I wish to thank all who responded!!
However, the answers I got make it look as though the input impedance of an
amp (at the cathode feedpoint) changes as the frequency changes!! This
doesn't seem to be right because the driving power , the amount needed at
the feedpoint, should remain constant insofar as the k-g voltage requirement
would always be the same for a given amount of output power. This is the way
it seems to me, BUT,
you may correct me if I'm wrong.(it wouldn't be the first time , I
reckon!!) (and maybe not the last either!!)
any comments??? Thanks
carl / kz5ca
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