Automatic frequency control for phase pulse receivers

Claim 1

AN AUTOMATIC FREQUENCY CONTROL CIRCUIT FOR PHASE PULSE RECEIVERS COMPRISING: A DEMODULATOR HAVING TWO INPUTS, ONE INPUT RECEIVING DISCRETELY PHASE SHIFTED SIGNALS AND A SECOND INPUT RECEIVING MODULATING SIGNALS MAINTAINING THE DISCRETELY PHASE SHIFTED SIGNALS CORRECT FOR PHASE DISCRIMINATION ON AN OUTPUT THEREOF; A VARIABLE FREQUENCY OSCILLATOR GENERATING FREQUENCY SIGNALS IN MULTIPLES OF SAID DISCRETELY PHASE SHIFTED SIGNALS ON AN OUTPUT THEREOF IN ACCORDANCE WITH A CONTROL SIGNAL ON AN INPUT THEREOF; A PHASE COMPARISON CIRCUIT HAVING ONE INPUT COUPLED TO THE OUTPUT OF SAID DEMODULATOR AND A SECOND INPUT COUPLED TO THE OUTPUT OF SAID VARIABLE FREQUENCY OSCILLATOR, EAC OF SAID INPUTS HAVING A SQUARING AMPLIFIER THREIN PRODUCING SQUARE WAVES, RESPECTIVELY, OF SAID DISCRETELY PHASE SHIFTED SIGNALS AND SAID GENERATED SIGNALS OF SAID VARIABLE FREQUENCY OSCILLATOR, THE OUTPUT OF THE SQUARING AMPLIFIER SQUARING SAID DISCRETELY PHASE SHIFTED SIGNALS BEING COUPLED THROUGH A DIFFERENTIATING NETWORK AND A ONE-SHOT MULTIVIBRATOR TO ONE INPUT OF A PHASE COMPARATOR NETWORK, AND THE OUTPUT OF THE OTHER SQUARING AMPLIFIER BEING COUPLED TO ANOTHER INPUT OF SAID PHASE COMPARATOR NETWORK COMPARING THE PHASE RELATION OF SAID SIGNALS PRODUCING ON AN OUTPUT OF SAID PHASE COMPARISON CIRCUIT A CONTROL SIGNAL, SAID OUTPUT BEING COUPLED TO SAID VARIABLE FREQUENCY OSCILLATOR INPUT; AND A FREQUENCY CHANGER CIRCUIT HAVING AN INPUT COUPLING THE OUTPUT OF SAID VARIABLE FREQUENCY OSCILLATOR AND AN OUTPUT COUPLING THE DEMODULATOR SECOND INPUT MODULATING SAID DISCRETELY PHASE SHIFTED SIGNALS CORRECTING SAME FOR PHASE DISCRIMINATION OUT OF SAID DEMODULATOR WITHOUT PHASE DISCRIMINATION OF SIDEBANDS.