Agc impedance converter for varactor diode tuner

Claim 1

In combination with a signal receiver of a type including AGC network means providing an AGC signal and a tuner of a type employing the voltage variable capacitance characteristic of a voltage variable capacitance diode for varying the tuning of said receiver and having an AGC signal input terminal; an AGC converter network for converting the AGC output signal of said AGC network means to a level and source impedance suitable for use with said tuner, said AGC converter network including first and second transistors having base, collector and emitter electrodes, means supplying said AGC output signal to said base electrode of said first transistor, first and second terminals at different DC potentials, means connecting said first terminal and said collector electrode of said first transistor, means connecting said first terminal and said emitter electrode of said second transistor, means connecting said second termInal and said collector electrode of said second transistor, means connecting said first and second transistors to turn on said second transistor in response to conduction of said first transistor, means connecting said collector electrode of said second transistor and said AGC signal input terminal, and means for applying a reverse bias between said base and emitter electrodes of said first transistor to provide a delayed AGC signal from said AGC converter network.