In article ,
William Sommerwerck wrote:
At the time Europe adopted PAL, the transmission systems had a lot of
non-linear group delay (the US systems didn't), which alters the hue.
The phase alternation causes the hue shifts to be "opposite"
(complementary) on alternate lines, so there is a visual averaging of
the hue. This is good, up to a point, but as the averaging pushes the
color towards white, the effect is visible desaturation.

Never seen this - despite having had colour TV since it started in the UK.

But I'm still not sure what you mean by 'non linear group delay'.

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Dave Plowman London SW
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