Signal plus noise to noise measuring equipment

Claim 1

APPARATUS FOR MAKING SIGNAL PLUS NOISE-TO-NOISE MEASUREMENTS IN ELECTRONIC EQUIPMENT HAVING A PULSED INPUT SIGNAL, SAID APPARATUS COMPRISING, A CONTROLLABLE-GAIN AMPLIFYING CIRCUIT ADAPTED TO RECEIVE A PULSED INPUT SIGNAL FOR OCCURS IN THE PRESENCE OF NOISE, SAMPLING MEANS COUPLED TO SAID AMPLIFYING CIRCUIT FOR SAMPLING THE NOISE DURING A SHORT TIME PERIOD IMMEDIATELY ADJACENT THE TIME OF OCCURRENCE OF EACH SIGNAL PULSE, MEANS COUPLED TO SAID SAMPLING MEANS FOR DERIVING A D.C. BIAS SIGNAL PROPORTIONAL TO THE MAGNITUDE OF SAID SAMPLED NOISE, MEANS RESPONSIVE TO SAID BIAS SIGNAL FOR CONTROLLING THE GAIN OF SAID AMPLIFYING CIRCUIT AS AN INVERSE FUNCTION OF SAID BIAS SIGNAL, WHEREBY THE OUTPUT OF SAID AMPLIFYING CIRCUIT IS AN INVERSE FUNCTION OF THE SAMPLED NOISE, GATING MEANS COUPLED TO RECEIVE OUTPUT SIGNALS FROM SAID AMPLIFYING CIRCUIT AND OPERATIVE TO PASS SAID OUTPUT SIGNALS ONLY DURING THE OCCURRENCE OF THE PULSES OF SAID INPUT SIGNAL, AND PULSE DETECTING MEANS COUPLED TO SAID GATING MEANS FOR DERIVING A DETECTED SIGNAL WHOSE MAGNITUDE IS PROPORTIONAL TO THE MAGNITUDE OF THE GATED PULSED SIGNALS PASSED BY SAID GATING MEANS.