Secam colour TV transmitter with coding circuit - has two reference signal generators, two sampling circuits, each with phase regulator

摘要

The coding circuit is for a SECAM colour television transmitter. It has a frequency modulator circuit for an oscillator, which will convert a modulating signal into a frequency modulated signal. The phase regulator loop in the sampling circuit will equalise the frequency of the modulated signal to that of a generated reference signal. There is a second sampling circuit (25,26) with a phase regulator loop linked to a second reference signal generator (24). This produces a second control voltage which adjusts the sensitivity of the frequency-modulator circuit.