Chapter 18
Pulldown
‘Up a bit … down a bit … a bit more … OK that’s it, lock it there.’ The sluice gate operator of the Hoover Dam followed his instructions precisely and the 60 Hz mains frequency of the USA was established. A similar scenario played out in Europe and a 50 Hz mains frequency was chosen. Half the world followed the lead of the USA, the other half followed the European standard, and the eventual market for video standards converters was created. A canny investor might have spotted the potential!
A while later in the USA, a member of the National Television Standards Committee commented, while viewing an early experimental colour image: ‘What’s causing that diagonal interference pattern?’ A few quick tweaks of a reference oscillator ...
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