Measurement of the settling time of a v.c.o. by varying the repetition rate of a square-wave generator

A steady-state method of measuring the transient settling time of a fast-tuning v.c.o. is described in which the control voltage is generated by a square-wave generator. The output function is effectively a trapezoidally modulated f.m. signal whose shape and spectral distribution of power depends on the settling time. The power intercepted by a 3rd-order Butterworth filter is calculated for several values of the settling time.