Re: 625-Line Television Broadcast Standards
Other advantages for adopting System I is near full chrominance bandwidth to be transmitted in both chroma sidebands, it also enables the chroma /sound beat to occour outside the the chroma bandpass limit i.e. 1.566MHz. as compared to system B/G with a 1.067MHz. beat. The result can look like coloured herringbone interference. Also Quadradure envelope distortion is minimised during chroma transients as a result of equal bandwidth non vestigial chroma sidebands.The problem is best seen during the transistion between the green and magenta bars on standard colour bars when receiving systemB/G. The P.A.L. system certainly helps minimise the problem however.
Victor.
|