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Old 23rd Jul 2016, 2:10 pm   #105
julie_m
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Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Earliest BBC2 Sets?

Nuvistors were short-lived because transistors were soon able to do their jobs, better.

I'd guess that European valve manufacturers -- who, remember, were also semiconductor manufacturers -- could see the writing on the wall: the new wonder material, silicon, was going to displace the thermionic valve from its throne any day soon now, so didn't want to introduce another blind-alley technology that might become obsolete even before the tooling was paid for, especially not if it would have required licensing foreign Intellectual Property. (We'd already been burned before, with exotic improved exhaust systems for steam engines that increased efficiency and reduced coal consumption -- just not by enought to outweigh the cost of the royalties.) Hence we ended up with stumpy little seven- and nine-pin valves, with extra anode and grid pins to minimise stray inductance (just like resistors, the inverses of inductances in parallel add up). And so the R&D boffins just had to jolly well work harder on inventing transistors with gain at UHF; because they, too, wanted decent pictures on their TV sets.
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