From: John Woodgate
Subject: Re: Digital divide by ten, 1949 style
Date: Sat, 21 Sep 2002 07:27:38 +0100
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Sat, 21 Sep 2002 08:19:20 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Tony Duell
wrote (in )
about 'Digital divide by ten, 1949 style', on Fri, 20 Sep 2002:
>John Woodgate (email@example.com) wrote:
>: I read in sci.electronics.design that Joe Morris
>: wrote (in ) about 'Digital divide by
>: ten, 1949 style', on Thu, 19 Sep 2002:
>: >But that brings up a question: what was the highest number of pins used
>: >on any production vacuum tube? (And this is going to make me go into
>: >my garage and look at the old image orthicon that's been sitting on a
>: >shelf for 40 years or so and count its pins...) Let's say that the
>: >word "production" means that it was produced to stock (not built to
>: >order) and intended for civilian users.
>: Excluding CRTs, 11 pins, AFAIK. European types ECC171, ECF174, EDD171
>No, it was at least 26 pins. The Trochotron counter tubes have 26 pins
>IIRC (although the holder is called a B26A or B27A). 17 pins round the
>outside (a circle divided into 18 parts, with one pin missing for
>location) and a separate circle of 9 pins in the middle.
>And to tie it in to the title of this thread, Trochotrons _are_
>divide-by-10 counters (although they need a 2-phase clock input, so
>aren't quite a single-valve divider).
Ah, I read 'consumer use', not 'civilian use', in the OP's text. Were
Trochotrons used by 'civilians'?
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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