The Synchrotector, A Sampling Detector for Television Sound

The paper describes an efficient and economic demodulator for intercarrier television sound. The circuit uses the method of sampling near zero passage of the carrier. This is accomplished in one-half of a double triode. The other half operates as a locked oscillator, whose cathode output is used to drive the sampler cathode. The phase angles between grid and cathode of the sampler are not in quadrature. A centering method to obtain coincidence between optimum fm detection and best AM rejection is described.