Manual or automatic transistor r. f. gain control system utilizing a voltage controlled variable resistance element

Claim 1

A GAIN CONTROL SYSTEM FOR A TRANSISTOR AMPLIFIER COMPRISING A TRANSISTOR HAVING BASE, COLLECTOR AND EMITTER ELECTRODES MEANS FOR APPLYING OPERATING POTENTIALS TO THE ELECTRODES OF SAID TRANSISTOR INCLUDING A FIXED FORWARD BIAS POTENTIAL ON THE BASE THEREOF AND THE EMITTER CIRCUIT OF SAID TRANSISTOR BEING COMMON TO THE INPUT AND OUTPUT SIGNAL CIRCUITS OF SAID TRANSISTOR A DIRECT CURRENT VOLTAGE CONTROLLED DIODE IN THE EMITTER CIRCUIT OF SAID TRANSISTOR, A PAIR OF VARIABLE DIRECT CURRENT VOLTAGE SOURCES, THE VOLTAGE OF ONE OF SAID VARIABLE DIRECT CURRENT SOURCES BEING A FUNCTION OF SIGNAL STRENGTH OF THE SIGNAL OUTPUT OF THE AMPLIFIER AND THE VOLTAGE OF THE OTHER OF SAID VARIABLE DIRECT CURRENT VOLTAGE SOURCES BEING MANUALLY VARIABLE, A GAIN CONTROL BUS COMMONLY CONNECTING SAID PAIR OF VARIABLE DIRECT CURRENT VOLTAGE SOURCES TO SAID DIRECT CURRENT VOLTAGE CONTROLLED DIODE TO VARY THE RESISTANCE THEREOF AND THE AMOUNT OF SIGNAL DEGENERATION THEREAT AND DIRECT CURRENT THERETHROUGH AS A FUNCTION OF THE VOLTAGE ON SAID GAIN CONTROL BUS A CONTROL SWITCH MEANS FOR ENABLING SAID MANUALLY VARIABLE SOURCE TO CONTROL SAID GAIN CONTROL BUS SO THAT SAID MANUALLY VARIABLE SOURCE CONTROLS THE VOLTAGE ON SAID GAIN CONTROL BUS, AND A CONSTANT DIRECT CURRENT SOURCE CONNECTED DIRECTLY TO THE EMITTER ELECTRODE OF SAID TRANSISTOR, SAID CONSTANT CURRENT SOURCE INCLUDING A RESISTOR OF SUCH LARGE MAGNITUDE THAT IT DETERMINES THE DIRECT CURRENT FLOWING THROUGH IT TO MAINTAIN A BIAS VOLTAGE ON THE EMITTER OF SAID TRANSISTOR TO ASSURE A GRADUAL TRANSITION FROM "ON" TO "OFF" OF SAID TRANSISTOR.