Receiver arrangement

Claim 1

A COMMAND RECEIVER OF THE TYPE ADAPTED TO RECEIVE A TRANSMITTED SIGNAL, WHICH SIGNAL HAS A PRESELECTED RADIO FREQUENCY AMPLITUDE MODULATED BY A PRESELECTED AUDIO FREQUENCY, AND TO ENERGIZE A RELAY IN RESPONSE THERETO COMPRISING, IN COMBINATION: AN ANTENNA FOR RECEIVING THE TRANSMITTED SIGNAL; A RADIO FREQUENCY TRANSFORMER HAVING A PRIMARY WINDING AND A SECONDARY WINDING, AND SAID PRIMARY WINDING CONNECTED TO SAID ANTENNA; A FIRST DETECTOR HAVING A FIRST PREDETERMINED SIGNAL GAIN FOR A FIRST CONDITION OF OPERATION AND A SECOND PREDETERMINED SIGNAL GAIN GREATER THAN SAID FIRST FOR A SECOND CONDITION OF OPERATION, AND SAID FIRST DETECTOR COUPLED TO SAID SECONDARY WINDING OF SAID RADIO FREQUENCY TRANSFORMER FOR RECEIVING THE TRANSMITTED SIGNAL COUPLED THERETO BY SAID SECONDARY WINDING AND SAID FIRST DETECTOR HAVING A CYCLICAL FREQUENCY GENERATING MEANS FOR CYCLICALLY ESTABLISHING THEREIN AT A PREDETERMINED SQUELCH FREQUENCY RATE, AN OSCILLATORY SIGNAL CONDITION AT SAID PRESELECTED RADIO FREQUENCY, MODULATED BY SAID PRESELECTED AUDIO FREQUENCY AND SAID PRESELECTED SQUELCH FREQUENCY AND SAID FIRST DETECTOR HAVING FILTER MEANS TO FILTER SAID PRESELECTED RADIO FREQUENCY AND SAID SQUELCH FREQUENCY TO PROVIDE A DETECTED AUDIO FREQUENCY SIGNAL AT SAID PRESELECTED AUDIO FREQUENCY; AMPLIFICATION MEANS COUPLED TO SAID FIRST DETECTOR FOR RECEIVING SAID DETECTED AUDIO FREQUENCY SIGNAL AND GENERATING A DC CONTROL SIGNAL IN A RESPONSE THERETO, SAID DC CONTROL SIGNAL HAVING A MAGNITUDE PROPORTIONAL TO THE STRENGTH OF THE TRANSMITTED SIGNAL RECEIVED BY SAID ANTENNA; A RELAY; A RELAY DRIVER AND GAIN CONTROL COUPLED TO SAID AMPLIFICATION MEANS AND TO SAID RELAY FOR RECEIVING SAID DC CONTROL SIGNAL AND ENERGIZING SAID RELAY IN RESPONSE THERETO FOR THE CONDITION OF SAID DC CONTROL SIGNAL BEING PRESENT FOR A PREDETERMINED TIME INTERVAL AND HAVING A MAGNITUDE AT LEAST AS GREAT AS A PREDETERMINED THRESHOLD VALUE; AND SAID FIRST CONDITION OF OPERATION COMPRISING SAID RELAY DE-ENERGIZED AND SAID SECOND CONDITION OF OPERATION COMPRISING SAID RELAY ENERGIZED, AND SAID CYCLICAL FREQUENCY GENERATING MEANS RESPONSIVE TO SAID ENERGIZING OF SAID RELAY TO PROVIDE SAID SECOND PREDETERMINED SIGNAL GAIN FOR THE CONDITION OF SAID RELAY ENERGIZED AND TO PROVIDE SAID FIRST PREDETERMINED SIGNAL GAIN FOR THE CONDITION OF SAID RELAY DE-ENERGIZED; AND SAID PREDETERMINED THRESHOLD VALUE OF SAID DC CONTROL SIGNAL CORRESPONDING TO A MINIMUM SENSITIVITY VALUE OF THE TRANSMITTED SIGNAL FOR THE CONDITION OF SAID RELAY DE-ENERGIZED AND SAID MINIMUM THRESHOLD VALUE OF SAID DC CONTROL SIGNAL CORRESPONDING TO A CUT-OFF VALUE OF THE TRANSMITTED SIGNAL, LESS THAN SAID MINIMUM SENSITIVITY VALUE FOR THE CONDITION OF SAID RELAY ENERGIZED.