An investigation into a proposal for a simplified television field synchronising signal

摘要

This report concerns a proposal which relates to a simplification of the 625/50 television field synchronisation signal;the object of the proposal is to reduce the duration of the synchronisation signal so as to leave more time in the field blanking interval for the transmission of data, test signals etc. The work described in this report was originally aimed at measuring the resistance to interference of the existing field synchronising signal and to use these measurements as a basis for assessing the suitability of proposed new forms of field synchronising signal However, resistance to interference was found to be substantially unaffected when using the proposed form of synchronising signal, but examination of the effects of using the proposed form of synchronising signal on the synchronisation and interlace of domestic television receivers led to further investigations. It was found that a small but significant number of receviers suffered impairment of interlace when operating on the proposed signal.