Current Usage of Vertical Interval Test Signals in Television Broadcasting

Vertical interval test signals (VITS) have been used for network transmission testing for about 20 years. What makes the subject of interest at the present time is: the recent adoption of a new series of network transmission test signals; the adoption of the VITS concept by the FCC in connection with the operation of television broadcast stations by remote control, and by the recent development of equipment which provides for the automatic remote monitoring of VITS and of other equipment which will provide for the automatic correction of distortions in the system as indicated by the test signals. The ultimate goal of VITS is higher quality television pictures --a goal which is becoming more and more important in order to fully exploit current technological advances including the trend towards larger picture display devices. This paper will describe the new network transmission test signals, the FCC test signals, how and why they differ, and how the signals are being utilized. The paper will also include a discussion of how the television industry is working together to develop a plan for the efficient use of all of the vertical blanking interval --in order to provide for these test signals as well as for a variety of other types of signals.