Could NTSC VIR = PAL

[old_tv_nut]

Originally Posted by Robert Grant

"Less critical for SECAM than PAL" caught my attention here.

I had always thought that the delay line was strongly encouraged in PAL for the color correction benefit, with some manufacturers leaving it out to save a few Marks (resulting in "Hanover bars", and called "Simple PAL") and others using a delay line to store alternate R-Y lines and escape patent royalties payment, wheras in SECAM a delay line would be absolutely essential as SECAM only transmitted one axis of chromience with each line.

My understanding: In PAL, the length of the delay determines if the chroma is exactly phased right from line to line. In an NTSC comb filter, the exact length of the delay determines if the chroma and luma sidebands are precisely separated. In SECAM, the delay is only providing low-resolution FM chroma, so doesn't need to be so precise.