Radio receiver means employing separable complementary units

Claim 1

IN COMBINATION, A PAIR OF SEPARATE SYSTEMS WHICH MAY BE OPTIONALLY INTERCONNECTED TO PROVIDE, SELECTIVELY, RECEPTION OF MONAURAL AMPLITUDE MODULATED SIGNALS AND STEREOPHONIC, SINGLE-CARRIER, AMPLITUDE MODULATED SIGNALS, SAID FIRST SYSTEM COMPRISING MEANS FOR RECEIVING A RADIO FREQUENCY SIGNAL, MEANS FOR HETERODYNING SAID RECEIVED SIGNAL TO A FIXED INTERMEDIATE FREQUENCY, DETECTOR MEANS COUPLED TO THE OUTPUT OF SAID HETERODYNING MEANS, AN AUDIO UTILIZATION CIRCUIT, A FIRST SIGNAL LEAD, MEANS FOR CONNECTING THE INPUT OF SAID AUDIO UTILIZATION CIRCUIT, SELECTIVELY, TO THE OUTPUT OF SAID DETECTOR MEANS OR TO SAID FIRST SIGNAL LEAD, SAID SECOND SYSTEM COMPRISING MEANS FOR DERIVING A SIGNAL AT THE INTERMEDIATE FREQUENCY FROM SAID HETERODYNING MEANS IN SAID FIRST SYSTEM, MEANS FOR SYNCHRONOUSLY DEMODULATING SAID DERIVED INTERMEDIATE SIGNALS, SAID DEMODULATING MEANS PROVIDING SEPARATE AUDIO FREQUENCY SIGNALS AT FIRST AND SECOND OUTPUTS, A SECOND AUDIO FREQUENCY SIGNAL UTILIZATION CIRCUIT CONNECTED TO SAID FIRST OUTPUT OF SAID DEMODULATING MEANS AND MEANS FOR CONNECTING SAID SECOND OUTPUT TO SAID FIRST SIGNAL LEAD IN SAID FIRST SYSTEM.