Results of active line-1 TV timing

Because of the increasing interest in time and frequency dissemination via television signals, NBS has sponsored an experiment using an active time and frequency code transmitted on a U. S. television network encompassing nationwide coverage. The code format is discussed and statistical results of system stability using the network path from New York City, N. Y., to Boulder, Colo., are presented through plots of phase with respect to time and plots of time domain stability using the Allan variance. Comparison is made of the frequency transfer capability of the line-1 method to the 3.57954 ... MHz color subcarrier signal used for network colorcasts. The active line-1 TV time system offers distinct advantages over existing dissemination methods utilized within the continental U. S. of principal interest is the short measurement period required for a time or frequency calibration. The system typically permits calibration of a remote standard to 1 part in 10¹¹within one-half hour.