Well, I was talking about the original trochotron that required an external magnetic ring to form the switched beam. This tube did not function as an indicator, as the Dekatron does. Used a pair of Dekatrons to make an electronic Roulette wheel in the late '50s. Almost like watching the ball roll around.
See http://en.wikipedia.org/wiki/Trochotron#History Bill Hawkins P.S. If you'd like to use twin triodes, I have a number of IBM 704 plug-in units with 8 sockets and 4 rows for parts. These can be saved from the dumpster by expressing an interest to [email protected]. The trochotron counter is also available, but shipping for 50 pounds may be expensive. -----Original Message----- From: J. Forster Sent: Saturday, January 09, 2010 5:15 PM They were also called Dekatron, See the tubecollector site. I doubt they are still available any more. OTOH, there are plenty of things like 12AX7s out there, as long as you don't need the "golden ear" brands. -John =============== > Only need one tube for a ring counter - the trochotron (q.v.). > Just happen to have a military counter based on them, nixie display, > > Bill Hawkins > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of J. Forster > Sent: Saturday, January 09, 2010 4:49 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Digital Clock kit - no Integrated circuits! > > How about using ring counters? No decoder/drivers needed. A tube ring > counter, driving a Nixie directly. > > -John > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
