Cross-colour and luminance twinkle in N.T.S.C. colour receivers with various display devices

It has been observed that under some conditions N.T.S.C. colour receivers employing single-gun tubes exhibit severe cross-colour and luminance twinkle due to the presence of high video-frequency luminance information and noise. From analysis of a simple case it is established that this effect is the result of sampling of the high-frequency luminance and therefore noise components by the colour selection process (necessary to decode the subcarrier chrominance information) which takes place at the screen. Methods of eliminating or substantially reducing this objectionable effect are discussed.