The Problem of Synchronization in Cathode-Ray Television

Abstract

This paper considers the effect of various types of transmitted synchronizing signals on the synchronization of television receiver circuits, with particular reference to a system operating on the present standard of 441 lines, 60 fields per second, interlaced scanning. Starting with a description of interlaced scanning, the various causes which can be responsible for pairing are described. A description of the nature of the transmitted signal and its method of utilization at a television receiver is followed by a discussion of the horizontal synchronizing signal wave shape. The effect of deflecting circuits on interlacing and the requirements to be fulfilled by the vertical synchronizing signal to ensure interlacing are examined. The various types of vertical synchronizing signals are discussed and compared. The conclusion is reached that the "narrow vertical" signal is best adapted to ensure good synchronization, good interlacing, and simple, cheap receiver circuits.