VOICE MULTIPLEX TELEVISION RECEIVER

摘要

PURPOSE:To reduce buzz interference by providing a filter having the gain of frequency shift at the prestage of a video intermediate frequency amplifier having a slope around the video carrier wave and negative-feeding back the outout of an local oscillator to the input of this filter. CONSTITUTION:A frequency adder 13 adds a negative feedback frequency beta to a frequency shift f1. A filter 14 has a gain of frequency shift in mu1 around the voice carrier frequency and an adder 15 gives a frequency shift fn and the frequency discrimination in the sensitivity mu2 is made at a frequency discriminator 16. Thus, the interference wave voltage is reduced to 1/mu1.mu2.beta.