摘要 |
Quadrature-related outputs of synchronized color reference oscillator at +(R-Y) and +(B-Y) phases are applied to a first matrix to develop a first matrixed signal of a third intermediate phase. Additional matrixing operations on the oscillator outputs develop second and third matrixed signals of different phases symmetrically disposed about the third phase. A differential amplifier, of substantially fixed gain, with differential inputs respectively responsive to the second and third matrixed signals, develops a fourth matrixed signal, with a phase in quadrature relation with said third phase, across an output load. The reference signal input for a demodulator is derived from signals appearing across said output load. A controlled amplifier, fed with the first matrixed signal, is disposed to supply said first matrixed signal as an additional oscillatory signal to said output load, when desired for hue adjustment purposes, with the magnitude of the supplied additional signal dependent upon the magnitude of difference, if any, between an adjustable control voltage and a reference voltage, and the polarity of the supplied additional signal dependent upon the sense of said difference.
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