Abstract: A digital AGC arrangement is responsive to the absolute value of a digital signal whose amplitude is to be gain controlled to generate an error signal. The digital value of the error signal is converted to an analog signal by a high-gain digital element such as a pulse width modulator or a comparator controlling a current source. The output thereof is filtered and applied to the gain control input of an amplifier whose gain is to be controlled thereby. This AGC is useful, for example, in a television receiver that includes an RF tuner, IF SAW filter and IF amplifier to receive television signals in both analog format, such as the NTSC, PAL and SECAM formats, and in digital format, such as the ATSC and DVB formats. IF signals from the IF amplifier are sub-sampled to digital signal form and are utilized for AGC, in addition to being processed by respective analog format and digital format processors.

Abstract: A receiver requiring only a single IF SAW filter and IF amplifier receives signals in both analog format and in digital format, such as the NTSC, PAL and SECAM analog television signal formats and the ATSC and DVB digital television signal formats. IF signals from the IF amplifier are sub-sampled to digital signal form and are processed by respective analog format and digital format processors. Control circuitry responsive to the presence of certain unique components of the signals in analog format and digital format determine which of the analog format and digital format processors is producing valid data and selects the valid data to be utilized. In a television receiver, the unique components of the signals may include carrier signals, synchronization signals, pilot signals and symbol timing, and valid data is applied to a television display.

Abstract: A system for processing both a composite video television (TV) signal and a video cassette recorder (VCR) playback signal containing a combined line noise canceller and comb filter sharing a single delay line and a 3.58 MHz oscillator that drives a quadrature demodulator for demodulating both playback chrominance signals extracted from the playback signal and television chrominance signals extracted from the television signal. The system also provides automatic gain control to both the composite video TV signal and the VCR playback signal.

Abstract: Cascaded multipliers are coupled to a source providing a periodic sawtooth deflection waveform, the amplitude of which varies with variations in the high voltage applied to an accelerating anode of a kinescope. The sawtooth signal is cubed by the cascaded multipliers and multiplied by the inverse square of a voltage which varies with changes in the kinescope anode potential. The system thus incorporates S-correction and means for correcting the deflection waveform to compensate for changes in the high voltage supplied to the kinescope anode.