A E1T Decade Scaler Tube raised from the dead

Posted on Feb 5, 2014

The E1T tube you see on the left has been `in the family` for as long as I can remember. Probably my father took it home from work (he worked at the Shell laboratory in Rotterdam) or he bought it in one of the surplus shops in Rotterdam my father and I used to visit every Saturday morning when I was a child. Because it was such a strange and funny

A E1T Decade Scaler Tube raised from the dead
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looking tube we always used to play with it. Being under the assumption that the tube was broken, I was never particularly careful with it, nor did I make any attempt to bring the tube to life. From the commonly available datasheet, I knew that this was not just a display device, but that the tube actually counts pulses and additionally displays the sum. This implies that the tube has a memory of the equivalent of 3. 5 bits! On top of that, the tube even has a provision to generate a carry for the next digit. How did they do it I work at the central Philips Research Laboratory in Eindhoven, Holland. Obviously, the Lab keeps a complete archive of all research reports and papers. Browsing through some old volumes of the Philips Technical Review in the library, I happened to stumble across a paper, which described the E1T tube in great detail [1]. It is one word beautiful! The whole paper reads like a poem, it is so elegant and ingenious; undoubtedly one of the masterpieces of vacuum tube engineering. Unfortunately there does not appear to be a fancy and concise name for the tube. Dieter categorizes the tube as a "beam Deflection Decade Counter Tube" [2]. I would have liked to believe Joris Roehrenbude who categorizes the E1T as a Trochotron [3]. It sounds a hell of a lot more interesting than a "Decade Counter Tube". Unfortunately on further investigation it appears that a Trochotron is really something completely different...

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