The only NOS tubes that might have been around would be branded as Burroughs and not Ultronics. I actually had a couple Burroughs tubes NIB that I purchased back in 1970 or 1971 before I found the Ultronics tubes in the back of magazines for sale by the surplus houses. I have kicked myself for not keeping the new Burroughs tubes and the boxes as a pristine reference for 45 years later, but who would have thought that we would be talking about this so long after the fact. Even in 1971, the Ultronics tubes were all pulls from systems that had been in operation and bought up by liquidators.
The shadow on the substrate may even exist on a NOS tube depending on the burn-in process that was used and the doping mix of materials in the gas that were used for stabilizing and sealing preceded the burn-in. From: 'jf...@my-deja.com' via neonixie-l [mailto:neonixie-l@googlegroups.com] Sent: Tuesday, August 30, 2016 3:28 PM To: neonixie-l Subject: Re: [neonixie-l] Re: b7971 segment current On Monday, August 29, 2016 at 9:31:39 PM UTC-7, A.J. Franzman wrote: ... They might be shorted to the back substrate and possibly even each other via the substrate... I think this is improbable. On the one tube that I dissected*, the back substrate is an insulating white ceramic with an insulating black ceramic overcoat. BTW, this is one of the reasons I think there are no NOS tubes. It would be a lot of unnecessary additional work to deliberately put the shadow pattern into the black ceramic overcoat. * My one catastrophic failure because the glass envelope could not withstand being struck by the floor. -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/38ea757e-b836-486c-bcf8-90b6f9c1f0e3%40googlegroups.com <https://groups.google.com/d/msgid/neonixie-l/38ea757e-b836-486c-bcf8-90b6f9c1f0e3%40googlegroups.com?utm_medium=email&utm_source=footer> . For more options, visit https://groups.google.com/d/optout. -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/57c5f7af.c6e6240a.5d8fa.7020%40mx.google.com. For more options, visit https://groups.google.com/d/optout.
