Abstract: Time jitter distortion of data pulses is measured by a test set which recovers a median leading and a median trailing edge from the data pulses, defines a point of time reference at the midpoint of the median leading and trailing edges, generates a digital representation of one-half the median pulse interval (i.e., the interval from the reference time to the median pulse edge) and digital representations of the intervals from the reference time to the data pulse edges, and calculates the difference between each data pulse digital representation and the half median pulse digital representation to obtain the distortion of each data pulse. The test set displays digital representations of selected ones of the calculated differences in accordance with a counting algorithm of the number of times that each of the various differences are calculated.