Thanks for the pictures. I only have one post variety with the wires. All other tubes, the Ultronics and the NOS Burroughs, have the trace connections and are basically identical except for the Ultronics/Burroughs branding. None have the full round insulator.
On Sunday, October 6, 2019 at 2:51:01 PM UTC-4, Jeff Walton wrote: > > Here are a couple examples of different construction: > > > > > > > > > > > > The older B7971s used wires on the backplane. The really early B7971s had > the center post and some had full top insulators as well. There may even > be more varieties from some of the others that have collected these tubes. > Amazingly, I have never had a 7971 fail except for physical damage. > > > > Jeff > > > > > > > > > > *From:* [email protected] <javascript:> [mailto: > [email protected] <javascript:>] *On Behalf Of *Robert G. > Schaffrath > *Sent:* Sunday, October 6, 2019 12:51 PM > *To:* neonixie-l > *Subject:* [neonixie-l] Re: I'm Back: ZM1022 and B-7971 > > > > Here they are. They are genuine Burroughs without the Ultronics branding. > There is no darkening in the tube and the pins show no scratches indicative > of having been inserted into a socket. IIRC (it has been 40 years), the > vendor (Poly Paks? Meshna?) obtained them from a repair facility were they > were spares for the Ultronics boards. They were sold as unused and not > pulls: > > > > [image: IMG_3926 - Copy.JPG] > > > > [image: IMG_3927 - Copy.JPG] > > > > [image: IMG_3928 - Copy.JPG] > > > > > > Now besides those new tubes, I have in additional the six Ultronics tubes > being used by my clock, this one used Burroughs tube that was installed on > one of the Ultronics boards I purchased way back when. This one is > different than any other B-7971 I have seen: > > > > [image: IMG_3921 - Copy.JPG] > > > > [image: IMG_3922 - Copy.JPG] > > > > The difference with this tube is it has a post sticking up above the > segment holder. I have no idea what the post does but none of the other > tubes has it. Also, as I recall when I tested the tube out, it has a > slightly darker red color than the Ultronics tubes. When I put it in my > clock, I could tell the difference next to the other five tubes. It might > have been that the tube had not "warmed" up or possibly the other tubes > have mercury or some other additive that lightened the color slightly. > > > > I have some other pictures of tubes I have that I will post in a new post. > > > > Robert > > > On Saturday, October 5, 2019 at 2:22:54 PM UTC-4, Greg P wrote: > > Welcome back Robert. > > > > Please if you can post some pictures of the NOS 7971 tubes you have. I've > and many in this group have never seen an NOS one. Seems they're all pulls > from the Ultronics boards. > > > > -- > 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] <javascript:>. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/623728a2-a1af-485f-89e7-28d6a8bee20f%40googlegroups.com > > <https://groups.google.com/d/msgid/neonixie-l/623728a2-a1af-485f-89e7-28d6a8bee20f%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/5a514ff2-c470-4d9d-a09a-ff3537bbe8d1%40googlegroups.com.
