.............and others for AGC use.
The result of numerous google searches has turned up conflicting answers, I'm trying to find out how the discrete transistor AGC stages work in TV & radio IF strips.
One answer states that varying the base voltage of the controlled stage varies its input impedance to the previous stage by varying the B/E bias, the other states that using variable bias varies the collector current - on which the stage's gain is dependent.
As hardly any manufacturers still use discrete devices for this purpose there seems to be very little I can find on this subject, please can anyone help?
TIA.