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PAL BETA LEVELS



It seems that some of you had the same question I did about the
apparent discrepancy between NTSC and PAL SP RY/BY levels.  I got
many responses, but I also got many requests to share the outcome,
so I will try to summarize here (at least how I understand it, from
the various responses I received):

1. Early Beta machines (pre-SP) had weird component levels, and
that's old history, so forget about them.

2. When SP machines were introduced, the component levels were
the same for PAL and NTSC (700mvp-p=75% saturation, 934mvp-=100%).
The Y signal of course was adjusted for setup/no-setup.  Life was
pretty good.

3. As the SP format gained popularity in EBU countries, it was noted
that 100% saturated signals tended to push the limits of the format,
and some problems were noted.  Since EBU countries typically used 100% 
saturated color bars, the problem surfaced in many locations.  In NTSC
countries, 75% bars did nbot present a problem.  And of course in both
arenas, program material was rarely if ever a problem.

4. EBU countries began adjusting the I/O stages of their machines to
accomodate the problem, setting 525mvp-p=75% and 700mvp-p=100%.  After
some time, even SONY adopted this practice, for PAL machines only, and
the new levels were refered to as "N10".

5. Somewhere along the line, EBU adopted the recommended practice of
using 75% bars. [But beware non-adherents or old tapes!]

So in summary, all PAL SP decks are now N10, much to the chagrin of
engineers using universal D-A convertors, to accomodated the 100%
colorbars no longer in general use.  There, did I get that right?

Thanks again to all those who contributed responses. I hope I haven't
mangled the information too much [my way of saying if you think I
got it all wrong, don't come after me with chainsaws.]

I am not an employee of Sony or any of its competitors and do not
now or ever have been affiliated with the governments of known EBU
countiries.


------------------------------------------------------------------
"Trust the computer industry to shorten "Year 2000" to Y2K. It was
this kind of thinking that caused the problem in the first place."
------------------------------------------------------------------
Bill Topazio, VP/Engineering     bt at mte.com     v:212-907-1225
Manhattan Transfer               New York, NY   f:212-687-2719
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