Signal-to-noise ratio meter

Claim 1

A SIGNAL-TO-NOISE RATIO METER FOR DETERMINING SAID RATIO OF A CONTINUOUS WAVE SIGNAL HAVING NOSE INCLUDED THEREWITH WHICH COMPRISES: (A) A TRANSLATION OSCILLATOR (B) MEANS FOR SINUSOIDALLY FREQUENCY SWEEPING SAID TRANSLATION OSCILLATOR, (C) A MIXER HAVING A PAIR OF INPUTS AND AN OUTPUT, SAID TRANSLATION OSCILLATOR CONNECTED TO ONE OF SAID INPUTS AND (D) MEANS COUPLING SAID CONTINUOUS WAVE SIGNAL AND NOISE INTO SAID OTHER MIXER INPUT, (E) VOLTAGE AMPLITUDE LIMITER HAVING ITS INPUT CONNECTED TO SAID MIXER OUTPUT, (F) FREQUENCY DISCRIMINATION MEANS CONNECED TO RECEIVE THE OUTPUT OF SAID LIMITER MEANS, (G) A PHASE DETECTOR HAVING A PAIR OF INPUTS AND AN OUTPUT, FOR COMPARING THE PHASES OF SIGNALS INTRODUCED AT SAID INPUTS AND PRODUCING AN OUTPUT HAVING AN AMPLITUDE PROPORTIONAL THERETO, (H) A SOURCE OF A SINUSOIDAL SIGNAL IMPHASE AND SYNCHRONIZED WITH THE SWEEP OF SAID MEANS FOR SWEEPING SAID TRANSLATION OSCILLATOR, (I) SAID SOURCE CONNECTED TO ONE INPUT OF SAID DETECTOR AND THE INPUT OF SAID DISCRIMINATOR CONNECTED TO THE OTHER OF SAID DETECTOR INPUTS, (J) A READ-OUT DEVICE FOR INDICATING THE VOLTAGE AMPLITUDE AT THE INPUT OF SAID DEVICE, (K) WHEREBY WHEN THE OUTPUT OF SAID DETECTOR IS APPLIED TO SAID READ-OUT DEVICE THE AMPLITUDE INDICATION THEREOF WILL BE PROPORTIONAL TO THE SIGNAL-TO-NOISE RATIO OF SAID CONTINUOUS WAVE SIGNAL.