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.
On Thursday, October 3, 2019 at 11:45:36 AM UTC-4, Robert G. Schaffrath wrote: > > It has been many years since I was active in any Nixie group. I had last > posted quite some time ago in the the Yahoo Groups Nixie forum. > > Recently I happened to do a search for some electronic components and one > of the "you might also be interested in" items was a Nixie clock kit. I was > rather surprised to see how inexpensive it was (obviously sans tubes) and, > upon further searching further, seeing the variety of tubes supported by > different kits. Way back in 2002 when I was back looking at Nixie tubes due > to the IEEE Spectrum article published back then, I purchased a lot of 25 > NOS Philips ZM1022's for a relatively cheap price that I planned to use for > a project. I even purchased an OZ2CPU kit and assembled it but then never > got around to actually doing anything with it. > > Fast forward to now and one of the items I saw was a pre-assembled > ZM1020/QS30-1 clock for USD$33 that required only the power supply, tubes > and CR1022 backup battery. For the price I decided to take a chance, since > I have plenty of ZM1022 Nixie tubes. I have to say I was pleasantly > surprised at the quality and functionality. It even has an anti-poisoning > routine. I like it so much I decided to get another one. > > Meanwhile I was looking to see what Nixie tubes sell for now and I am > stunned at how the prices have skyrocketed. I see very few ZM102x tubes and > the prices are insane. At least the Chinese QS30's are not that expensive > though they still sell for more than I paid for the ZM1022's. I was also > amazed to see what B-7971's are selling for now. I still have my old MM5311 > based six tube clock that I built back in 1979 and have occasionally > upgraded to newer components. I recently saw individual used tubes selling > for ~USD$130 each. I am thinking I will need to put the box of 6 NOS > Ultronics B-7971's I still have in a Safe Deposit box LOL. I've had them > for almost 40 years now and paid about USD$5 each for them from either Poly > Paks or Meshna Electronics (you could buy used tubes for $1 less so I > decided to spend the extra $1 and buy unused). I also have one used > Burroughs branded (not Ultronics) B-7971 as well that has a slightly > different interior assembly compared to the Ultronics tubes. So I currently > have a grand total of 13 tubes if I add in the six I am using with the old > clock. > > Finally, I have been thinking of replacing my now 40 year old handiwork > with the OZ2CPU kit I assembled as it supports B-7971's. The design I > followed uses the line frequency for time keeping. Unfortunately it tends > to drift quite a bit during the day and any line noise can cause the time > to change quite a bit. Also I am finding the whine from the multiplexed > tubes bothers me more now than it did when I was younger. That tells me it > is time to modernize. > > > Robert > -- 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/0e8a9b2a-b6fb-4cc1-99aa-8b8c741aba9d%40googlegroups.com.
