Circuit arrangement for the measurement of the absolute delay of a quadrupole especially of a transmission line

Claim 1

A CIRCUIT ARRANGEMENT FOR THE MEASUREMENT OF THE ABSOLUTELY DELAY OF A QUADRUPOLE, COMPRISING A FIRST ADJUSTABLE SIGNAL GENERATOR WHICH GENERATES A FIRST, FIXED SIGNAL FREQUENCY, A SECOND SIGNAL GENERATOR WHICH ALTERNATELY GENERATES A CONSIDERABLY LOWER SECOND SIGNAL FREQUENCY FROM SAID FIRST FREQUENCY AND A THIRD SIGNAL FREQUENCY WHICH DEVIATES SLIGHTLY FROM SAID SECOND SIGNAL FREQUENCY, A MODULATOR HAVING INPUTS, TO WHICH SAID SIGNAL GENERATORS ARE RESPECTIVELY CONNECTED, AND AN OUTPUT, A DEMODULATOR, THE QUADRUPOLE TO BE MEASURED HAVING ITS INPUT CONNECTED WITH THE OUTPUT OF THE MODULATOR AND ITS OUTPUT CONNECTED WITH THE INPUT OF SAID DEMODULATOR, A PHASE MEASUREMENT DEVICE HAVING INPUTS WHICH ARE CONNECTED RESPECTIVELY TO THE OUTPUT OF SAID DEMODULATOR AND TO SAID SECOND SIGNAL GENERATOR, WHICH DEVICE GENERATES AN OUTPUT VOLTAGE WHOSE AMPLITUDE IS PROPORTIONAL TO THE PHASE DIFFERENCE OF THE VOLTAGE AT THE TWO INPUTS, AND VISUAL INDICATING MEANS WHICH INDICATES THE AMPLITUDE OF SAID OUTPUT VOLTAGES, WHICH INDICATING MEANS IS CALIBRATED IN VALUES OF THE GROUP DELAY FOR AT LEAST ONE OF THE SECOND SIGNAL FREQUENCY AND THE THIRD SIGNAL FREQUENCY AND FROM WHICH CAN BE READ OFF, THE DIFFERENCE $R=R1-R2 OF THE INDICATED VALUE R1 FOR THE SECOND SIGNAL FREQUENCY, AND OF THE INDICATED VALUE R2 FOR THE THIRD SIGNAL FREQUENCY, WHEREBY THE EXPRESSION