Dave Plowman (News) wrote:
Think you're well into hindsight. When the UK PAL system was finalised
(1960?), computers were some esoteric device in a lab. But in any case a
major priority of any colour TV system then was that it can be easily
receivable on a monochrome only set - and not make that set more expensive
to produce.

That's almost irrelevant. When the UK went to digital TV broadcasts (was
that around 2000 with Sky's digital terrestrial service?) there was no
no need to continue to support PAL. After all much of their material
was NTSC anyway. They were encoding the signals in one place, so there was
no restriction on what equipment was used except cost, and on the set end
they could of used anything they wanted.

I expect they chose PAL because it was the existing standard, and they could
buy subassemblies cheaply.

However ATSC was compeltely different. It was supposed to be a new standard,
not a re-hashing of an old one. There was no need to keep NTSC compability
as long as it could be created in set top boxes.

Note that there were and still are two other incompatble digital TV standards
in use in the US. The cable companies use one of their own, and the DBS
companies use a different one. Since there are two competing DBS companies,
each using their own incompatible encryption, you could say there are four
incompatible ones.

They all use some sort of MPEG TS transmission, but the streams can not
be read with the other company's devices.

Geoff.



--
Geoffrey S. Mendelson N3OWJ/4X1GM
Those who cannot remember the past are condemned to misquote it.