Intermodulation distortion plotter

Claim 1

A SYSTEM FOR PLOTTING EITHER SINGLE FREQUENCY RESPONSE OR INTERMODULATION RESPONSE OF A SYSTEM UNDER TEST OVER A PREDETERMINED FREQUENCY BAND COMPRISING: A SCANNING OSCILLATOR FOR PROVIDING A FREQUENCY SPECTRUM HAVING A WIDTH COINCIDENT WITH THE WIDTH OF THE PREDETERMINED FREQUENCY BAND; MEANS RESPONSIVE TO SAID SCANNING OSCILLATOR FOR DERIVING A PAIR OF SCANNING FREQUENCIES ALWAYS HAVING A CONSTANT FREQUENCY SEPARATION, THE FREQUENCY BAND OF ONE OF SAID PAIR OF FREQUENCIES HAVING A WIDTH COINCIDENT WITH THE WIDTH OF SAID PREDETERMINED FREQUENCY BAND; MEANS FOR APPLYING SAID PAIR OF SCANNING FREQUENCIES TO SAID SYSTEM UNDER TEST; A DISPLAY SYSTEM FOR PROVIDING AN ORTHOGONAL COORDINATE PLOT OF AMPLITUDE VERSUS FREQUENCY; MEANS FOR SYNCHRONIZING THE SCANNING OF SAID FREQUENCY COORDINATE OF SAID PLOT WITH THE FREQUENCY VARIATIONS OF ONE OF SAID PAIR OF SCANNING FREQUENCIES; MEANS RESPONSIVE TO THE DIFFERENCE FREQUENCY OF SAID PAIR OF SCANNING FREQUENCIES DERIVING FROM SAID SYSTEM UNDER TEST FOR DERIVING A FIRST CONSTANT FREQUENCY SIGNAL HAVING AN AMPLITUDE VARYING OVER SAID PREDETERMINED FREQUENCY BAND IN ACCORDANCE WITH THE INTERMODULATION DISTORTION RESPONSE OF SAID SYSTEM UNDER TEST; MEANS RESPONSIVE TO SAID PREDETERMINED FREQUENCY BAND DERIVING FROM SAID SYSTEM UNDER TEST FOR DERIVING A SECOND SIGNAL HAVING AN AMPLITUDE VARYING OVER SAID PREDETERMINED FREQUENCY BAND IN ACCORDANCE WITH THE SINGLE FREQUENCY RESPONSE OF SAID SYSTEM UNDER TEST; AND MEANS FOR APPLYING SAID FIRST AND SECOND SIGNALS TO THE AMPLITUDE COORDINATE OF SAID DISPLAY SYSTEM, WHEREIN SAID DISPLAY SYSTEM COMPRISES: A CATHODE RAY TUBE HAVING A DEFLECTABLE CATHODE RAY BEAM; AND MEANS FOR SELECTIVELY DEFLECTING SAID CATHODE RAY BEAM IN ACCORDANCE WITH THE AMPLITUDES OF SAID FIRST AND SECOND SIGNALS, AND WHEREIN SAID MEANS FOR SELECTIVELY DEFLECTING INCLUDES MEANS FOR SUCCESSIVELY AND ALTERNATELY APPLYING SAID FIRST SIGNAL AND SAID SECOND SIGNAL TO SAID DISPLAY SYSTEM, AND MEANS FOR DEFLECTING SAID CATHODE RAY BEAM IN ONE POLARITY DIRECTION DURING THE TIME WHEN SAID FIRST SIGNAL IS APPLIED TO SAID DISPLAY SYSTEM AND FOR DEFLECTING SAID BEAM IN THE OPPOSITE POLARITY DIRECTION DURING THE TIME WHEN SAID SECOND SIGNAL IS APPLIED TO SAID DISPLAY SYSTEM.

Claim 2

A SYSTEM FOR PLOTTING EITHER SINGLE FREQUENCY RESPONSE OR INTERMODULATION RESPONSE OF A SYSTEM UNDER TEST OVER A PREDETERMINED FREQUENCY BAND COMPRISING: A SCANNING OSCILLATOR FOR PROVIDING A FREQUENCY SPECTRUM HAVING A WIDTH COINCIDENT WITH THE WIDTH OF THE PREDETERMINED FREQUENCY BAND; MEANS RESPONSIVE TO SAID SCANNING OSCILLATOR FOR DERIVING A PAIR OF SCANNING FREQUENCIES ALWAYS HAVING A CONSTANT FREQUENCY SEPARATION, THE FREQUENCY BAND OF ONE OF SAID PAIR OF FREQUENCIES HAVING A WIDTH COINCIDENT WITH THE WIDTH OF SAID PREDETERMINED FREQUENCY BAND; MEANS FOR APPLYING SAID PAIR OF SCANNING FREQUENCIES TO SAID SYSTEM UNDER TEST; A DISPLAY SYSTEM FOR PROVIDING AN ORTHOGONAL COORDINATE PLOT OF AMPLITUDE VERSUS FREQUENCY; MEANS FOR SYNCHRONIZING THE SCANNING OF SAID FREQUENCY COORDINATE OF SAID PLOT WITH THE FREQUENCY VARIATIONS OF ONE OF SAID PAIR OF SCANNING FREQUENCIES; MEANS RESPONSIVE TO THE DIFFERENCE FREQUENCY OF SAID PAIR OF SCANNING FREQUENCIES DERIVING FROM SAID SYSTEM UNDER TEST FOR DERIVING A FIRST CONSTANT FREQUENCY SIGNAL HAVING AN AMPLITUDE VARYING OVER SAID PREDETERMINED FREQUENCY BAND IN ACCORDANCE WITH THE INTERMODULATION DISTORTION RESPONSE OF SAID SYSTEM UNDER TEST; MEANS RESPONSIVE TO SAID PREDETERMINED FREQUENCY BAND DERIVING FROM SAID SYSTEM UNDER TEST FOR DERIVING A SECOND SIGNAL HAVING AN AMPLITUDE VARYING OVER SAID PREDETERMINED FREQUENCY BAND IN ACCORDANCE WITH THE SINGLE FREQUENCY RESPONSE OF SAID SYSTEM UNDER TEST; AND MEANS FOR APPLYING SAID FIRST AND SECOND SIGNALS TO THE AMPLITUDE COORDINATE OF SAID DISPLAY SYSTEM, WHEREIN SAID DISPLAY SYSTEM COMPRISES: A CATHODE RAY TUBE HAVING A DEFLECTABLE CATHODE RAY BEAM; AND MEANS FOR SELECTIVELY DEFLECTING SAID CATHODE RAY BEAM IN ACCORDANCE WITH THE AMPLITUDES OF SAID FIRST AND SECOND SIGNALS, AND WHEREIN SAID MEANS FOR SELECTIVELY DEFLECTING INCLUDES MEANS FOR SUCCESSIVELY AND ALTERNATELY APPLYING SAID FIRST SIGNAL AND SAID SECOND SIGNAL TO SAID DISPLAY SYSTEM, AND MEANS FOR DEFLECTING SAID CATHODE RAY BEAM IN ONE POLARITY DIRECTION DURING THE TIME WHEN SAID FIRST SIGNAL IS APPLIED TO SAID DISPLAY SYSTEM AND FOR DEFLECTING SAID BEAM IN THE OPPOSITE POLARITY DIRECTION DURING THE TIME WHEN SAID SECOND SIGNAL IS APPLIED TO SAID DISPLAY SYSTEM.