Frequency keyed transistor oscillator signal receiver

Claim 1

IN COMBINATION, A SOURCE OF SIGNALS, AN OSCILLATOR RESPONSIVE TO SAID SIGNALS AND COUPLED TO SAID SOURCE, SAID OSCILLATOR COMPRISING A TRANSISTOR HAVING BASE, EMITTER AND COLLECTOR ELEMENTS, A FEEDBACK TRANSFORMER HAVING PRIMARY AND SECONDARY WINDINGS, SAID PRIMARY WINDING CONNECTED IN SERIES BETWEEN SAID EMITTER ELEMENT AND GROUND, A CAPACITOR SERIES-CONNECTED BETWEEN SAID BASE ELEMENT AND ONE END OF SAID SECONDARY WINDING, THE OTHER END OF SAID SECONDARY WINDING BEING CONNECTED TO GROUND, A LEAK RESISTOR CONNECTED BETWEEN SAID BASE ELEMENT AND GROUND, TWO POWER SUPPLY TERMINALS, A DROPPING RESISTOR SERIES-CONNECTED BETWEEN ONE TERMINAL AND SAID COLLECTOR ELEMENT, THE OTHER TERMINAL BEING GROUNDED, AN OUTPUT TRANSFORMER HAVING PRIMARY AND SECONDARY WINDINGS, THE PRIMARY WINDING OF THE LAST-MENTIONED TRANSFORMER BEING SERIES-CONNECTED BETWEEN SAID ONE TERMINAL AND SAID COLLECTOR ELEMENT, A SPEAKER COUPLED TO THE SECONDARY WINDING OF SAID LAST-MENTIONED TRANSFORMER, AND MEANS COUPLING SAID SOURCE TO SAID EMITTER ELEMENT FOR APPLYING SAID SIGNALS THERETO, SAID TRANSISTOR BEING BIASED TO CUT-OFF AND THE FIRST-MENTIONED TRANSFORMER BEING REGENERATIVELY COUPLED BETWEEN SAID EMITTER AND BASE ELEMENTS, WHEREBY A SIGNAL FROM SAID SOURCE TRIGGERS SAID OSCILLATOR INTO OPERATION WHICH IN TURN ACTUATES SAID SPEAKER.