In message , Dave
writes
On 05/05/2011 22:21, Dave Liquorice wrote:
On Thu, 5 May 2011 20:26:59 +0100, Ian Jackson wrote:

If it's for playing on a DVD player, as well as the region coding, the
player and or TV might not like the PAL 625-line signal.

But the signal on the disk hasn't, hopefully, been anywhere near PAL
coder, digits all the way. It's the player that coverts the digital
signal from the disc to whatever analogue is required. Be that PAL,
SECAM or NTSC... Wouldn't the player be connected via HDMI anyway or
at the very least RGB SCART avoiding PAL completely? Frame rate might
be a problem but the programme may not last as long...

I hadn't thought about that either. Thanks.

If I remember correctly, 'PAL' 625-line TV sets, which have a 50Hz field
(25Hz frame) scan rate, have little trouble locking to an 'NTSC' video
signal, which has a 60Hz field (30Hz frame) scan rate. This is because
the faster field rate triggers off the scan 'early', and it locks OK.

On the other hand, an NTSC set doesn't work with a PAL signal, because
the trigger from the slower field scan rate occurs 'too late' - ie after
the scan has decided it can't wait any longer for a trigger pulse, and
has already started off on its own (free-running). As a result it won't
lock.
--
Ian