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Posted by Jan Panteltje on 10/10/06 10:21
On a sunny day (Tue, 10 Oct 2006 08:21:41 +0100) it happened "Stephen"
<stephen@junkmail.sptv.demon.co.uk> wrote in
<egfhm5$1t5$1$8300dec7@news.demon.co.uk>:
>There's an excellent and very detailed explanation of the SECAM system here:
>http://www.pembers.freeserve.co.uk/World-TV-Standards/Colour-Standards.html#SECAM
>
>The SECAM colour subcarrier frequency is
>4.40625 MHz on "Red" lines
>4.25000 MHz on "Blue" lines
>
>The precise frequency for PAL is
>4.43361875 MHz
It is important to notice that in SECAM the carriers are frequency modulated,
and in PAL and NTSC are quadrature modulated.
This FM made SECAM very suitable for videotape recording, but impossible for
mixing.
That is why the studios used PAL, then the final product was converted to SECAM.
PAL is in fact improved NTSC.
SECAM stood for 'System Ensenee Contre Amerique' (excuse my French) and is from the
The Gaulle period, in cooperation with Russia.
SECAM had many problems, version IV was the last one I remember....
One problem with SECAM was, because of the FM carrier, that it was always visible as a
bad pattern on BW TVs, so not _really_ BW compatible.
SECAM should never have been invented.
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