A chroma signal recording and reproducing circuit of a magnetic recording and reproducing apparatus having a recording circuit for frequency-modulating a luminance signal of a color video signal, low-frequency converting a chroma signal and frequency-multiplexing those signals for recording and a reproducing...http://www.google.fr/patents/US4524380?utm_source=gb-gplus-shareBrevet US4524380 - Chroma signal recording and reproducing circuit
