wow and flutter of a tape player is measured by playing a recording of a constant frequency test tone, digitally sampling and storing each period of the tone over a test interval, subtracting the average period from each period to obtain deviation data, calculating the fft of the deviation data, and then calculating power magnitude and wow and flutter. the apparatus includes an interface board which squares the signals from the player, and a desktop computer having a timing board for gating a counter for each square wave pulse to sample the periods, a memory for storing the samples, and a cpu programmed to analyze the samples according to the test method.
