Frequency modulation multiplex receiver using a visual indicator to control local oscillator

Claim 1

AN INDICATOR AND CONTROL CIRCUIT FOR A FREQUENCY MODULATION RECEIVER CAPABLE OF RECEIVING MULTIPLEX AND NON-MULTIPLEX SIGNALS AND HAVING A LOCAL OSCILLATOR OPERABLE UPON THE APPLICATION OF A GIVEN BIAS VOLTAGE THERETO FOR PRODUCING CARRIER SIGNALS REPRESENTATIVE OF THE SUPPRESSED CARRIER SIGNALS AT THE TRANSMITTER, SAID INDICAOR AND CONTROL CIRCUIT INCLDUING IN COMBINATION, CIRCUIT MEANS FOR DETECTING OF MULTIPLEX SIGNALS BY THE RECEIVER, SIGNALS UPON RECEIPT OF MULTIPLEX SIGNALS BY THE RECEIVER, RECTIFIER MEANS CONNECTED TO SAID CIRCUIT MEANS FOR RECTIFYING THE PILOT SIGNALS DETECTED AND AMPLIFIED THEREBY, A NEON BULB AND A REVERSE POLED ZENER DIODE CONNECTED IN SERIES TO SAID RECTIFIER MEANS, AND CONDUCTING RECTIFIED PILOT SIGNALS THEREFROM, SAID ZENER DIODE CONNECTED IN VOLTAGE DROP THEREACROSS WHEN IN REVERSE CONDUCTION, AND CONDUCTOR MEANS FOR CONNECTING THE LOCAL OSCILLATOR ACROSS SAID ZENER DIODE TO SUPPLY OPERATING BIAS VOLTAGE THERETO ACCORDING TO THE GIVEN VOLTAGE DROP ACROSS SAID ZENER DIODE IN THE PRESENCE OF RECTIFIED PILOT SIGNALS CONDUCTED THROUGH SAID NEON BULB, SAID NEON BULB PRESENTING A HIGH RESISTANCE IN THE ABSENCE OF RECTIFIED PILOT SIGNALS TO PREVENT REVERSE CONDUTION THROUGH SAID ZENER DIODE THEREBY REMOVING BIAS VOLTAGE FROM THE LOCAL OSCILLATOR.