Regarding the yield? Just my (and others) experience with 'new old stock' tubes. I don't have any information on what the yield was at the time of manufacture. Its easy to rationalize a low yield because of the large seal between the glass and the body, but that would just be guesswork.
Interesting that the affected tubes were better in the original photos. In the U.S. we have a product called 'deoxit' that is used to fix old electrical contacts that may have some dirt/corrosion on them. It is just sprayed on the contacts and then the device is used as normal, though I don't know what the breakdown voltage is of the product. I have used it in old vacuum tube devices. On Tuesday, November 14, 2023 at 12:56:18 AM UTC-5 Magnedyne wrote: > > Alright, thanks for the tips. I’ll see what I can do. Not doubling the > current on other tubes should be obvious, if anything ill modify the > circuit on those to run on like 60% current or something, don’t want those > to wear out after all. How long would I double the current on the affected > tubes? I’m guessing until it lights up entirely, but what if it doesn’t? I > don’t want to risk damaging any tubes further unless I have access to a > replacement. Interesting regarding the yield, where did you find that info? > Paul Andrews schrieb am Montag, 13. November 2023 um 22:55:13 UTC+1: > >> Because all the segments are in the same plane, it is possible that they >> could all get deposits equally, so increasing the current may work. Yes, >> the current is controlled by a resistor. The documentation I linked you to >> gives the recommended current for each segment. To try to re-condition the >> segments I would double the current, but I would only do that with the >> affected tubes. >> >> These tubes are known for having a low yield so it is possible that the >> affected tubes have other problems, such as outgassing. I would be very >> careful when removing them from any socket they may be in to avoid breaking >> a seal between the pin and the tube. >> >> On Monday, November 13, 2023 at 4:22:00 PM UTC-5 Magnedyne wrote: >> >>> >>> Furthermore I should mention that the partial glow does not affect only >>> specific elements of the tube but any element inside the tube. >>> Can this be caused by deposits? >>> Nicholas Stock schrieb am Montag, 13. November 2023 um 21:56:10 UTC+1: >>> >>>> WHAT A FIND!!! OMG. I didn't even know there were smaller versions of >>>> the ZM1350 (shame on me!). >>>> >>>> The tubes with the partially lit segments can probably be revived with >>>> a little extra current... just be careful not to burn them during the >>>> healing process (if it works..). >>>> >>>> Wow.. >>>> >>>> Welcome to the group, >>>> >>>> Nick >>>> >>>> On Mon, Nov 13, 2023 at 12:07 PM Magnedyne <[email protected]> >>>> wrote: >>>> >>>>> Well, this serves as my introduction and and as a thread about a >>>>> beautiful sign I just picked up. >>>>> Firstly something about myself. >>>>> I’m a 17 year old collector and (hobby) historian of vintage >>>>> computers, my interests are mainly minis, mainframes, early micros and >>>>> kit/diy computers. But I’ve got a few other different bits and bobs >>>>> throughout the history of technology as well. >>>>> Now back to the reason I joined this group. >>>>> I came across an absolutely beautiful Telefunken advertising sign for >>>>> the, frankly underdocumented, Telefunken Varisymbol tubes. They were >>>>> Telefunkens response to the Burroughs 7971 alphanumerical tubes. These >>>>> were >>>>> only sold for a very brief amount of time and exclusively in Europe. >>>>> Interestingly these are flat like panaplex tubes and the anode is not >>>>> a grid, but a coating on the inside of the tube. These are the earliest >>>>> gas >>>>> discharge tubes, well the ones I’m aware of anyhow, which used such a >>>>> coating. >>>>> The sign is a handmade one off which was lugged around to fairs to >>>>> advertise the Varisymbol to potential Customers. It implements all three >>>>> sizes of the Varisymbol ZM1350 ZM1360 & ZM1370. It can alternate between >>>>> „TELEFUNKEN“ and „VARISYMBOL“ at four different speeds. Switching between >>>>> the sign reading „TELEFUNKEN“ three times, then „VARISYMBOL“ three times >>>>> and the sign reading „TELEFUNKEN VARISYMBOL TELEFUNKEN“/ „VARISYMBOL >>>>> TELEFUNKEN VARISYMBOL“ is possible as well. Unfortunately three tubes >>>>> don’t display quite properly. I’m hoping it’s just the electronics, I >>>>> haven’t had time for a detailed diagnosis yet. Even if it’s the tubes, it >>>>> seems to be the most common type at least, the ZM1350 which seems to have >>>>> popped up most often in the past. >>>>> Any further info about the Varisymbol is greatly appreciated. >>>>> Cheers, >>>>> Magnedyne >>>>> [image: IMG_0026.jpeg] >>>>> >>>>> [image: IMG_0025.jpeg] >>>>> [image: IMG_0021.jpeg] >>>>> >>>>> >>>>> >>>>> -- >>>>> 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/20e32d2c-3ac1-4656-b532-77b22f6a35f1n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/neonixie-l/20e32d2c-3ac1-4656-b532-77b22f6a35f1n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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