Abstract: A method and apparatus for synchronizing a received television signal to a subcarrier locked signal is provided. The apparatus includes a comparison block for determining whether the received television signal and subcarrier locked signal are related by a predetermined fixed frequency relationship and for providing indications of the same, and a signal generation block for dividing down the subcarrier locked signal according to the predetermined fixed frequency relationship so as to provide an output signal which is synchronized with the subcarrier locked signal, and at a frequency determined according to the fixed frequency relationship when the signals are related. The apparatus is particularly useful in PIP applications where the received television signal is a horizontal signal and the subcarrier locked signal is a four times multiple of the subcarrier frequency.

Abstract: Apparatus and methods for remodulating digital luminance and color difference components for display as PIP information, or together with other composite video components for multi-PIP and test pattern applications are disclosed. A digital encoder is used for conducting a digital quadrature modulation on the color difference components and for digitally adding the luminance signal thereto prior to the converting of the remodulated information into an analog format. Preferably, the digital video information output by the encoder is in the form Y1+(R-Y)1, Y1 +(B-Y)1, Y2-(R-Y)1, Y2-(B-Y)1, Y3+(R-Y)2. Y3+(b-Y)2, Y4 -(R-Y)2, . . . , where Y is the luminance component, R-Y and B-Y are color difference components, and where the numbers index received samples of the video components with the luminance component being sampled at twice the frequency of the color difference components.

Abstract: A stabilized gated oscillator that provides pulses at a predetermined repetition rate in phase coherence with a gating signal includes a ceramic resonator in a feedback resonant circuit between the output terminal and the input terminal of a linear amplifier. The resonant circuit, which establishes the repetition rate, is constructed to provide an oscillator frequency in a frequency range between two resonant frequencies of the ceramic resonator wherein the ceramic resonator acts as an inductance.

Abstract: A gated oscillator circuit for generating a sampling signal for digitally processing television signals, uses an LC oscillator to achieve, high frequency stability and reduced edge jitter. Circuitry is provided on both sides of a tank circuit in the oscillator for decoupling the tank circuit from other active circuit elements thereby enhancing the frequency stability.