Stabilized color television subcarrier regenerator circuit

A subcarrier regenerator circuit for use with a television receiver comprising:

• a phase detector having first and second inputs;
• a voltage-controlled oscillator having a regenerator output connected to said first input of said phase detector;
• a fixed-frequency oscillator;
• a first switch for switching said second input of said phase detector between said fixed-frequency oscillator and a color burst signal derived from the television receiver video signal;
• error signal processing circuit means for producing a control signal for said voltage-controlled oscillator in response to an output of said phase detector;
• switching control means for causing said first switch to switch said fixed-frequency oscillator to said phase detector during the vertical retrace period of the video signal.

A method of generating a television receiver color subcarrier signal to be used by the receiver color signal synchronous demodulators comprising the following steps:

• generating a subcarrier output signal in response to a control signal;
• generating a second output signal at a predetermined subcarrier frequency;
• detecting a color burst signal from a video signal provided by the receiver;
• making a first phase comparison between said subcarrier output signal and said second output signal during the vertical retrace period of the video signal;
• making a second phase comparison between said subcarrier output signal and the color burst signal;
• and
• generating said control signal in response to said first and second phase comparisons.