Phase and amplitude control of vertical modulation in horizontal scan of CRT high resolution television

摘要

In a system for high resolution television achieved by vertical modulation of the horizontal scan at a frequency twice the color subcarrier, the modulation signal is derived from the color subcarrier at both the camera and receiver by squaring the color subcarrier sinusoidal signal, inverting the squared waveform, differentiating the inverted and uninverted square waveforms and from the combined differentiated pulses producing a train of pulses at a frequency twice the color subcarrier. This train is then applied to a transistor connected as a class B amplifier with the vertical deflection coil and a parallel capacitor as an LC resonant load. The current to the coil is provided by a regulated power supply that is adjustable to adjust the amplitude of the vertical deflection of the horizontal scan.