Dalibor, First of all, many thanks for the book!
"mercury dispenser" - That's a great solution! Do you know maybe who is selling those? About stems, lead glass - that is a good solution too. I didn't pay attention on its viscosity - good to know, thanks. So it should be easy to make an oven for melting the lead glass. I have though about microwave oven, but I think there is a problem with overheating the pins, I'm not sure that it will work. But for 600 degC you can make a small size oven very easy, and cheap. My reason for choosing boroilicate glass is because it is hard glass, not an easy to break, and it doesn't need too much preheating. But of course high temperature is a problem. All about glass to metal seals you can find in Kohl 1960 book: Materials and Techniques for Electron Tubes. I assume that you already have it, but if you don't you can find it here: http://www.tubebooks.org/technical_books_online.htm Regards, Vladimir On May 12, 8:50 pm, Dalibor Farný <dali...@farny.cz> wrote: > Hi Vladimir, > > I found another solution, "mercury dispenser", it is prefabricated ring > with some compound of mercury and something else (Titan), You can use it > like a getter - heat and activate it.. > > As for the stems - it should be possible to make a simple form from > graphite (one big hole, several small through - for pins, stem would be > upside down here), place a wires inside, place some pieces of glass and > cast it in microwave oven, watch this: > > http://home.c2i.net/metaphor/mvpage.html > > It will be probably the best to use a lead glass for the stems and > soda-lime glass for the envelope - all nixies I saw use this combination.. > Lead glass has much lower melting point, somewhere around 600C, and what is > the killer feature - it has 100 times lower viscosity than soda glass, so > it can flow in every hole in the form and join nicely the pin wires.. It > has so low viscosity that all bubbles of air go out from the glass.. I > think that is the reason why the lead glass is used in original nixies.. > Lead glass should be used with dumet wire, easy to get - it is low oxygen > copper borated. > > You are great negotiator (with producers ;-) ) > > write me an email for the book.. > > Dalibor > > 2012/5/12 Vladimir Vucicevic <vladimir.cik...@gmail.com> > > > Hi Dalibor, > > > Maybe you are right about stainless steel and mercury, I'll think > > about it. > > I mean, I know that it is the best solution, nixies can last over 10k > > hours, but with molybdenum 3-5k hours are achievable I hope. > > I work in company in embedded systems design so I know a few companies > > > > > > > > > that cut stainless steel for PCB stencils (for component assembly). > > That is expensive, but it is possible that thinner sheets can be cut > > in companies that cut plastics and glass with low power lasers and > > with less precision. For 20 euros you can cut whatever you like. > > > I wrote to Moores company, and they were very kind to help me. Of > > course, I said that I will need a few thousands pieces a year (maybe I > > will :) ) and I got myself an offer. For a custom made stem i have to > > pay 2000 euros, and every stem will cost 6 euros for minimum quantity > > of 100 pieces. They have a lot of stems that you can by of the shelf > > without having to pay for tooling (with 11 and more pins, borosilicate- > > kovar combination) you just have to ask for a bigger quantity (>100). > > It is a fair deal, if you ask me. They have big diameters too > > (40-50mm) for your big tubes. For working with borosilicate glass you > > need high temperatures (>1000 deg C), and multi-pin stem is not an > > easy thing to make. You need to make tooling out of carbon, and to > > figure out how to get it to 1200 degC. Furnace for that cost a lot (I > > spoke with CEO of one glass company from Serbia, he said that I will > > need more that 10k Euros for that, because for temperatures over 1000 > > degC it is a whole bunch of expansive materials, but I think it > > shouldn't be that much). Another trouble is how to prepare kovar pins > > for sealing. There is a lot of methods provided from a lot of authors > > but it seams like too much experimenting. > > I also wrote to Fredericscom company. I'm still waiting for offer, but > > they answered quickly. You just have to say that you mean business, > > and you will get sweet talk immediately :). One company even called me > > on a phone right after my mail - world is in a crisis, every costumer > > is important. :) > > > I know about Simax, every glass item in Serbia that goes in oven is > > from Simax. :) > > > Don't forget about the book! You promised. ;-) > > > Regards, > > > Vladimir > > > On May 11, 8:36 pm, Dalibor Farný <dali...@farny.cz> wrote: > > > Hi Vladimir, > > > > thats nice to hear about small nixies, I am going to make nixies in size > > of > > > ZM1040, and then I will go for much bigger tubes ;-) > > > > The book will be tomorrow.. > > > > As for the cathode material - I think stainless steel in combination with > > > mercury dispenser were used in latest nixies, so it will be better than > > > molybdenum. I will work with mercury, it is toxic, but it is not so bad.. > > > it doesnt change a DNA, it doesnt make a cancer and the "halflife" of it > > in > > > human body is 50 days.. (50 days and a half of mercury in your body is > > > away..). > > > > I am curious about laser cut cathodes! > > > > I tried to write to Moore company about stems, but no answer, what > > > companies did You write to? I would also buy some borosilicate stems.. Do > > > You know something about how the stems are made? You wrote something > > about > > > tooling - I have no idea about tools to make it, probably some drilling > > > machine.. > > > > As for the glass - I use Simax, local producer, it is also borosillicate > > > (3.3) glass, good experience with it.. > > > > Thank You, > > > > Dalibor > > > > 2012/5/11 Vladimir Vucicevic <vladimir.cik...@gmail.com> > > > > > Hi Dalibor, > > > > > I am from Belgrade, Serbia. Same as you I am trying to make some nixie > > > > tubes, but my goal is to make tube as small as possible. > > > > Thanks a lot for the book, I am looking forward for it! > > > > > About nixies, I am going to use molybdenum cathodes because I want to > > > > try to avoid adding mercury. I saw some diagrams where molybdenum > > > > cathodes were suggested instead of stainless steel. Although stainless > > > > steel with mercury is the best solution for long life, molybdenum is > > > > also good. > > > > Also, I will try to cut cathodes with laser. Just need to compare > > > > prices, if it is not too much I prefer laser. > > > > > About glass work, I am currently in contact with few companies which > > > > produce glass stems. If you can fit in stems that they have in stock > > > > it is around 5 euros per stem if you buy more than 100 pieces. Custom > > > > made stems are expensive (more that 1500 euros for tooling). > > > > Combination of borosilicate glass and kovar alloy can be ordered. I am > > > > going with that one too. > > > > > Also if you need borosilicate glass for kovar welding go directly to > > > > Schott company. Schott 8250 is glass made just for that. They said > > > > that they make certain amount of this glass once in a year, but they > > > > always have something in stock. Minimum quantities are not too big. > > > > > Regards, > > > > Vladimir > > > > > On May 10, 10:23 pm, "Tidak Ada" <offl...@zeelandnet.nl> wrote: > > > > > Hi Dalibour, > > > > > > It would be nice to get a copy ! > > > > > Please make the scans of each page separate. It's a munch's work to > > > > rework > > > > > it trying to get double sided pages. > > > > > 600ppi bitmap is fine for text only pages. For pages with photo's > > 300ppi > > > > > gray scale is fine. > > > > > Markings from the library are easy to remove by PhotoShoping.... > > > > > > succes > > > > > > _____ > > > > > > From: neonixie-l@googlegroups.com [mailto: > > neonixie-l@googlegroups.com] > > > > On > > > > > Behalf Of Dalibor > > > > > Sent: donderdag 10 mei 2012 21:52 > > > > > To: neonixie-l@googlegroups.com > > > > > Subject: [neonixie-l] Re: looking for Weston: Cold cathode glow > > discharge > > > > > tubes > > > > > > Hi all, > > > > > > I finally find the book and scanned it, I am going to share it with > > You, > > > > but > > > > > I have to first remove all signs of the library where I borrowed it > > ;-) > > > > > I should not be illegal, it so old book.. > > > > > > I am also preparing a workshop for making nixie tubes at home, I am > > at > > > > the > > > > > same point as Dan, leaking system ;-) You can watch my progress > > > > onhttp://dalibor.farny.czItryto share all info, even sometimes too > > briefly > > > > > and delayed.. > > > > > > As for the other questions here: > > > > > > - gas mixture > > > > > search for "Penning mixture" - it is called after its inventor > > Penning > > > > (and > > > > > Addink). It is Neon and Argon 0.01 - 1%. More or less argon increases > > > > > breakdown voltage. > > > > > - anode material > > > > > use stainless steel, 0.2mm thick, photo etching > > > > > - cathode material > > > > > Cathode material has big influence on breakdown voltage (the same gas > > > > > mixture: Molybdenum cathode 150V, Fe cathode 240V) I plan to use > > > > stainless > > > > > steel 0.1mm thick (316L low carbon, vacuum casted). I disassembled a > > > > Z566M > > > > > tube and did some tests on cathodes and I think it is stainless > > steel, > > > > > Molybdenum would be much brittle and wouldn't melt in 1900C flame as > > this > > > > > did.. > > > > > > - cathode distance > > > > > use the same distance as in commercial tubes, somewhere around > > 1.5-2mm > > > > > should be OK. more in Weston. > > > > > > - gas pressure > > > > > 30-40 torr, higher is better, because it prevents cathode sputtering > > = > > > > > longer lifetime, but higher pressure also means higher breakdown > > voltage > > > > and > > > > > higher power consumption.. > > > > > > Vladimir, Dan, where are You from guys? I am from Czech Republic.. > > > > > > Daliborhttp://dalibor.farny.cz > > > > > > Dne úterý, 10. dubna 2012 14:46:12 UTC+2 Dalibor napsal(a): > > > > > > Hello guys, > > > > > > I am looking for the book from G.F. Weston, "Cold cathode glow > > discharge > > > > > tubes", 1968, but it is (surprisingly) sold out everywhere ;-) > > > > > > is there someone so kind to provide me a PDF or some other ebook? > > > > > > Thank You! > > > > > > Dalibor > > > > > > Dne úterý, 10. dubna 2012 14:46:12 UTC+2 Dalibor napsal(a): > > > > > > Hello guys, > > > > > > I am looking for the book from G.F. Weston, "Cold cathode glow > > discharge > > > > > tubes", 1968, but it is (surprisingly) sold out everywhere ;-) > > > > > > is there someone so kind to provide me a PDF or some other ebook? > > > > > > Thank You! > > > > > > Dalibor > > > > > > Dne úterý, 10. dubna 2012 14:46:12 UTC+2 Dalibor napsal(a): > > > > > > Hello guys, > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. 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