Hi,
Dave Woodman <dave_at_naffnet.org.uk> said:
> John Honniball wrote:
>
> > Dave Woodman wrote:
> > >
> > > Except, of course, in those large parts of the world that use PAL, and other
> > > parts that use SECAM, and....
> >
> > Thanks for pointing that out!
>
> You're welcome!
>
> >
> >
> > Just to add a bit of technical info, in the PAL-I system, as used
> > in the UK, the composite video is inverted before being amplitude
> > modulated onto the carrier. That means that the sync pules are
> > peaks of high-amplitude radio signal and bright areas of the
> > image are low-amplitude signals. The reason for this is to
> > reduce the average RF power required at the transmitter. Quite
> > a clever idea, really.
>
> There is also another benefit:- any impulse noise that interferes with
> the video results in a white pin-point on the picture, as oppose to a black
> blob (especially when the HT is poorly regulated...).
>
The other way about ;-) Interference on PAL produces unobtrusive black
blobs as opposed to annoying "snow".
--
Cheers,
Stan Barr stanb_at_dial.pipex.com
The future was never like this!
Received on Sun Jun 16 2002 - 13:15:01 BST