PAL replay circuit for colour video recorder - uses NTSC signals on video disc with colour sync. pulses produced from frequency corresp. to colour carrier by splitting into components

摘要

The relay circuit converts NTSC signals on a video disc into PAL signals for reproduction on a t.v. screen. The chroma signal's second sideband produced when mixing the decoded video signal is used to form a second colour line. The frequency of the colour carrier in the second sideband is converted by mixing into the frequency of the colour carrier in the first sideband, which corresponds to the PAL carrier frequency. The PAL colour sync. pulses are produced from a frequency corresp. to one of the colour carriers by splitting the pulses into +45 deg. and -45 deg. components.