An Automatic Hue and Differential Phase Correction Scheme for NTSC Receivers Using A New Vertical Interval Reference Signal

The phase errors between the regenerated subcarrier and chrominance signal results in wrong reproduction of hue in a NTSC receiver and requires frequent adjustment of the hue control. The VIR system which was developed to perform automatic hue control in NTSC receivers eliminates only static phase errors but does not correct differential phase. This paper proposes a modified Vertical Interval Reference signal for automatic correction of hue and differential phase errors in NTSC system, and describes the design and development of associated receiver circuitry. Experimental results based on simulatued errors are presented.