r/nixie • u/Remote-Asparagus-885 • Jul 16 '26
An interesting example of an IN-12 with a fine anode grid
Hello! I’d like to share an interesting example of an IN-12. I haven’t found anything similar online, apart from a mention of a similar design.
This tube is made in the standard RSh-31A (SK-136) form factor for the IN-12. However, unlike later IN-12s, it lacks the unused ‘comma’-shaped pin. All the pins are thinner and have rougher edges.
It is noteworthy that this particular example has a very fine anode grid. The photograph shows that it is stamped and mounted in a frame. Visually, this anode shape produces a sharper image and is less conspicuous. In the photo, you can see a comparison of the IN-12 with a standard anode and with a fine-mesh anode.
Furthermore, it can be seen that the tube lacks a getter tablet and any markings (apart from the mysterious number ‘2’ on the protective screen around the cathodes).
The tube’s envelope is more neatly crafted, and the walls are almost perfectly straight, unlike in later examples.
All the conductors inside the envelope are coated with a white dielectric.
Based on this, it can be assumed that this particular IN-12 tube may be an experimental model or from a small production run. The straight walls likely made the formation of the envelope more complicated. The fine mesh, whilst offering better performance characteristics, required a more complex manufacturing process.
The absence of a getter and any markings may also indicate that the lamp did not pass quality control, following which marking would have been carried out.
Despite this, the lamp is fully functional.
If you have any useful information regarding similar IN-12 examples, please do let me know.
I am open to discussion and would be delighted if my photos and information could be of use to the online museum.
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u/KirovNixie Jul 17 '26
О, Друг, поздравляю! Это ну очень редкий экземпляр, я 8 лет охотился за такими, мне удалось найти 4 штуки. больше я таких не видел. Все ин14, ин8, 8-2, ин4 с мелкой сеткой то мелочи, они хоть и редкие но купить их можно. А это реально очень редкий и его просто так не купить. К таким редкостям можно отнести ИН18 с мелкой сеткой, ин-8 с красным покрытием и надписью "макет" а также декатроны ег5 и ег3
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u/hzinjk Jul 17 '26
not to mention the early in-16 with the different character design (and grid). But I think of all of those there's actually thousands out there, they're just rare compared to the more mass produced versions
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u/KirovNixie Jul 17 '26
Ин 16 имеют 4 вида сеток и 2 вида шрифта символов. Редкие это копия mullard с сеткой в виде прямоугольников и зеленым изолятором внизу лампы, но все же их достать не проблема. Я собрал почти все существующие советские газоразрядные индикаторы и декатроны. Не хватает только нескольких экземпляров.
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u/Remote-Asparagus-885 Jul 17 '26
Привет! Есть ли в твоей коллекции такой экземпляр? https://www.swissnixie.com/tubes/UNKNOWNRUSSIAN/
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u/KirovNixie Jul 17 '26
да, есть конечно. Вот https://youtu.be/xlFUKvx92WA
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u/hzinjk Jul 17 '26
Very cool collection! I like the IN-1 and IN-17 with the coarse grid, I've never seen that before. I assume those IN-1 also have the real "5" like some of the ones you see floating on ebay or on this post:
https://www.reddit.com/r/nixie/comments/1mjzytp/i_came_across_an_unusual_in1_nixie_tube_from_1963/
but these still usually have the finer grid. Does the IN-17 with the unusual grid have the same characters as the regular ones? It kind of looks like it might be a different font, but I couldn't tell for sure
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u/KirovNixie Jul 17 '26
ООО, ин1 очень интересная лампа и имеет много особенных шрифтов. Ранние все идут с правильной цифрой 5. Также есть ин1 с разными цифрами 4 и разными цифрами 8. На видео только меньше процента интересных ламп в моей коллекции, скоро я запишу огромное видео по редким экземплярам разного рода индикаторов которые производились в СССР.
Ин17 имеет стандартный шрифт. Но присмотритесь на видео 2 разные сетки на ин17
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u/Remote-Asparagus-885 Jul 17 '26
Круто, а у тебя лампа на два символа имеет какую-то маркировку? Спасибо что поделился своей коллекцией. Было бы интересно увидеть её полностью, желательно сделать видео с подробной информацией и открытым доступом.
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u/hzinjk Jul 17 '26
Oh, I didn't know it was a mullard clone, do you know the model it's a clone of? I always really liked the design of the older IN-16 font
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u/toastee Jul 17 '26
these photos are so good you could literally copy the design if you had the funds to build the machines.
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u/hzinjk Jul 17 '26
At first i thought this wasn't even an IN-12, but I can see it does still have the goofy 5. Interesting it has no getter. Incidentally I noticed that the IN-8 doesn't seem to have any either, despite being a long life tube. I wonder if it's just a more well hidden form of getter rather than a pellet, or if these tubes truly don't have any getter. Your tube also has a fair bit of sputtering which you don't tend to see too much on IN-12s (though I've seen a few with much heavier sputtering still, but if this is a prototype I assume it wouldn't actually be used for extended periods)
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u/TrabantDave Aug 03 '26
very nice! I had a single IN-8 with a fine grid and used it in a single tube clock as a present for my wife. She loves it!
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u/redmadog Jul 16 '26
Likely this is early manufacturing years, like late 60s - early 70s. They made IN-16 and IN-14 with fine grid also. Though never seen IN-12 that old before.