Timing jitter measurement display

Abstract

A timing pulse jitter measurement display suitable for observing large jitter deviations, such as those caused by head changes between fields of video data in a video tape or cassette recorder (VTR or VCR), selects a range of data samples about each timing pulse for processing. The data samples are acquired using a stable, jitter free, precision clock. Residual signals, such as residual subcarrier in a video signal, are removed from the selected data samples and a precise timing point is determined for each timing interval with respect to a stable reference point. The deviations of the timing points from a baseline, derived from the precision clock and representing the stable reference points occurring at a nominal timing interval, are displayed, and means provided for determining peak to peak jitter along any portion of the acquired set of displayed data samples. Averaging also is provided between acquisition sets of data samples to reduce noise and highlight phase errors due to some repetitive influence.