Phase locked variable frequency oscillator system with sweep circuit

Claim 1

A VARIABLE FREQUENCY OSCILLATOR SYSTEM COMPRISING: A PHASE CONTROL CIRCUIT INCLUDING A VARIABLE FREQUENCY OSCILLATOR HAVING A REACTANCE MEANS FOR GOVERNING THE OUTPUT FREQUENCY THEREOF, A PHASE DETECTOR HAVING A FIRST INPUT FOR RECEIVING A SIGNAL FROM SAID VARIABLE FREQUENCY OSCILLATOR AND A SECOND INPUT FOR RECEIVING AN INPUT SIGNAL COMPRISING A SERIES OF PULSES HAVING A REPETITION RATE LESS THAN THE OUTPUT FREQUENCY OF SAID OSCILLATOR TO PROVIDE A FIRST TYPE PULSE OUTPUT SIGNAL WHEN SAI SIGNALS APPLIED TO SAID PHASE DETECTOR ARE IN-PHASE, AND TO PROVIDE A SECOND TYPE OUTPUT SIGNAL WHEN SAID SIGNALS APPLIED TO SAID PHASE DETECTOR ARE OUT OF PHASE, AND A VARIABLE GAIN AMPLIFIER RESPONSIVE TO OUTPUT SIGNALS PROVIDED BY SAID PHASE DETECTR FOR DERIVING A CONTROL SIGNAL TO VARY SAID REACTANCE MEANS; A SWEEP AND LOCK CIRCUIT INCLUDING SAID VARIABLE GAIN AMPLIFIER MEANS, MEANS FOR OBTAINING A D.C. BIAS VOLTAGBE IN RESPONSE TO SAID SECOND TYPE OUTPUT SIGNAL INCLUDING MEANS FOR APPLYING SAID D.C. BIAS VOLTAGE TO SAID VARIABLE GAIN AMPLIFIER AFTER A PREDETERMINED TIME DELAY FOR DECREASING THE GAIN THEREOF AS SAID D.C. BIAS INCREASES; A DECREASE IN GAIN CAUSING THE OUTPUT SIGNAL OF SAID VARIABLE GAIN AMPLIFIER TO DECREASE THEREBY SWEEPING SAID CONTROL SIGNAL IN A FIRST DIRECTION; AND MEANS FOR ALTERING THE FREQUENCY RESPONSE OF SAID PHASE CONTROL CIRCUIT.