Frequency sweep circuit for phase controlled oscillator

Claim 1

IN AN AUTOMATIC PHASE CONTROL OSCILLATOR CIRCUIT INCLUDING A PHASE COMPARATOR AND AN OSCILLATOR HAVING A VARIABLE REACTANCE CIRCUIT CONNECTED TO THE OUTPUT OF SAID PHASE COMPARATOR AND ARRANGED SO THAT AN EXTERNAL SYNCHRONIZING SIGNAL AND THE OUTPUT SIGNAL FROM SAID OSCILLATOR ARE APPLIED TO SAID PHASE COMPARATOR TO OBTAIN AN OUTPUT SIGNAL VOLTAGE CORRESPONDING TO THE PHASE DIFFERENCE BETWEEN SAID SIGNALS, SAID OUTPUT SIGNAL VOLTAGE BEING APPLIED TO SAID OSCILLATOR TO SYNCHRONIZE THE FREQUENCY OF THE OSCILLATOR OUTPUT WITH THAT OF SAID EXTERNAL INPUT SIGNAL, THE IMPROVEMENT ESSENTIALLY CONSISTING OF AN AUTOMATIC FREQUENCY OSCILLATOR CONTROL CIRCUIT, COMPRISING FEEDBACK CIRCUIT MEANS CONNECTED BETWEEN THE OUTPUT OF SAID OSCILLATOR AND THE INPUT OF SAID VARIABLE REACTANCE CIRCUIT FOR PROVIDING AN OSCILLATOR FREQUENCY CONTROL SIGNAL INCLUDING FREQUENCY DISCRIMINATOR MEANS HAVING AN OUTPUT CORRESPONDING TO THE FREQUENCY DIFFERENCE BETWEEN THE SIGNAL OUTPUT OF SAID OSCILLATOR AND THE INPUT SIGNAL FOR PRODUCING OSCILLATORY CONTROL OF SAID VARIABLE REACTANCE CIRCUIT, SAID FEEDBACK CIRCUIT HAVING A LOOP GAIN OF NOT LESS THAN ONE.