Subcarrier regeneration circuit for color television receivers

A subcarrier regeneration circuit for a color television receiver adapted to receive a composite color television signal including a color burst contained in a flyback interval and a chroma signal between successive ones of the flyback intervals, the subcarrier regeneration circuit comprises:

• a phase detector for generating an output representative of the difference in phase between the color burst and a reference subcarrier;
• a first sample-and-hold circuit operable to sample the output from the phase detector during the interval of the color burst and storing the sampled signal into a first capacitor;
• means for generating a sampling pulse with a duration equal to the flyback interval minus the interval of the color burst;
• a second sample-and-hold circuit operable to sample the output from the phase detector during the interval of said sampling pulse and storing the sampled signal into a second capacitor;
• and
• a voltage controlled oscillator receptive of the voltage difference between the first and second capacitors to generate a signal at said reference subcarrier and operable to control the frequency and phase of said subcarrier in accordance with said voltage difference.