Automatic frequency control apparatus for television receiver

摘要

An automatic local oscillation frequency control apparatus for a television receiver is disclosed, wherein a video intermediate frequency (VIF) signal is applied to an FM discriminator for generating an AFC voltage through a phase shifter comprised of a serial-parallel resonance circuit, and one of the serial resonance frequency and the parallel resonance frequency of the serial-parallel resonance circuit is selected to be a frequency near a picture carrier frequency while the other is selected to be a frequency which is made by subtracting one half of a differential frequency between the picture carrier frequency and a sound carrier frequency from the picture carrier frequency. The present apparatus can attain an automatic frequency control having a wide pull-in range and a wide hold range.