You're right concerning the type numbers. Wasn't that a kind of cathode poisoning during the off state of the tube?. Especially tubes that stayed in off state for long times where notorious for that 'illness'.
An other idea is this I looked to Frank Philipse's pages and discovered a DCC90, that only consumes 220mA @ 1,4V for DC heating. However, it has a direct heated cathode that functions for both the halves of the system. Further one should probably look for subminiature tunes, either triodes or pentodes, connected as triode. May be there are also suitable subminiature thyratrons. (Anyhow, cold cathode triggers). At the other hand of the range, there is a possibility of making BCD and ring counters using relays. Disadvantage is the power consumption may be enormous if a counter comes in the '1111' state and stays there for a long time (hours and 10-s of hours) eric -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David Forbes Sent: dinsdag 7 februari 2012 21:01 To: [email protected] Subject: Re: [neonixie-l] Re: Nixie clock with vacuum tubes On 2/7/2012 12:42 PM, David Forbes wrote: > > Another dual triode that was common as dirt in computers was the 6211. > It's faster than the 5963. IBM bought millions of 'em from GE 50 to 55 years ago. > Oops, they're not quite a 12AU7. To quote from the IBM 650 computer's descriptive paper presented to the ACM in 1954, "Approximately 2000 tubes are used in the machine. They are the 5965, 6211, 12AY7, 6AL5, 2D21 and 5687. Types 6211 and 5965 are similar to the 12AV7. These are used because they meet special IBM acceptance tests." I have some other books at home with more information on the development of these special digital tubes. As I recall, it was a complete mystery why the tubes failed in service, the problems being ascribed to black magic until the chemists sorted it out. -- David Forbes, Tucson, AZ -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
