all my tubes have 2040 printed on them, all of them have a TD71 sticker, and two say 425A5 on a sticker.
On Tuesday, October 21, 2014 1:55:29 PM UTC-5, Dekatron42 wrote: > > Here is a photo of a tube marked 2040 on the glass and 425A5 on the base > http://www.radiomuseum.org/tubes/tube_2040.html , I can't vote for its > authenticity but I have both types but not one with both markings. > > I have also scraped away the black paint from 1C21s and they have an > identical construction inside and work just as well as the others being > touch sensitive. I read a few old patents where they mentioned that the > black paint was there just there to make them less light and touch > sensitive, the other difference I read about was that the ones used in > touch buttons were selected for their voltage, which is how some are marked > - the last digit in 425A5 marks the voltage 2 = 72V, 5= 75V on the tubes I > own. > > You can read more here as they have been discussed earlier: > https://groups.google.com/forum/#!msg/neonixie-l/Ygr3IqWcVDQ/2fCV8ANU5XcJ > > /Martin > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/f09a812a-2109-4fb8-b7f4-3fa47279aaf7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
