Re: ITA - Engineering for Colour

In article <1145359526.906891.143250@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
davidrobinson@xxxxxxxxxxxxxxxx <davidrobinson@xxxxxxxxxxxxxxxx> wrote:
m wrote:
I was leant a similar type book about BBC Television (published in 1958)
recently and also scanned it in!!

Try here:- http://www.bostonmanor.plus.com/ExComms/BBC_handbook.html

Unfortunately a couple of pages missing but an interesting read

Blimey - no pre-EQ pulses in a 405-line video signal!

I'd _read_ that somewhere, but never actually seen a waveform diagram -
you learn something every day! The picture area on the line immediately
before V-sync!

Did it work? I mean, surely the picture content combined with imperfect
sync separation would make the V-sync unreliable?


Of course it worked. For many years, too. Your worries about sync
separation were thougth of, too. In the early days, the picture was sat on
a 'pedestal' of 5% to give complete isolation of picture and sync. This
had been dropped by the time I went to work at the Beeb (1962) [it is still
used in the ISA, I believe]. As one of my research colleagues put it " why
waste 5% of transmitter power broadcassting nothing?"
Cheers,
David.
(far too young to know anything about this!)

--
From KT24 - in drought-ridden Surrey

Using a RISC OS5 computer
.

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