PURPOSE: To evade jitter measurement in a pause state due to malfunction, etc., by discriminating whether the RF signal of an R-DAT deck is a normal playback state or pause state.

CONSTITUTION: The RF signal from the waveform generating circuit 1 of the R-DAT deck is inputted to an indication meter 8 through a measurement system 9 to measure the jitters of an R-DAT. At this time, a BPF 3A extracts ATF signal F1 contained in signals A and B from the measured RF signal and the extracted signals are supplied to a retriggerable monostable multivibrator 4C to generate pulses. Its output is inputted to a comparator 6 through an LPF 5 and an analog switch 7 provided to the signal input terminal of an indication meter 8 for jitter measurement is driven with the output of the comparator 6 to halt a measurement indication in the pause state.