Numitron tubes

[init4fun]

In my recent haul of vintage electronic stuff I found three of these Numitron tubes . I looked them up and found that the Numitron appears to be a sort of low voltage Nixie tube . Having three I was having all kinds of great thoughts of building some kind of display with them , but when I looked up the actual tube number "DR2020" I found that instead of having all the segments a Nixie would have had , these tubes can only do + - and the number 1

Oh well , even though they aren't all that useful I figured I'd post them up for folks who may have never seen one ...

[Chip Chester]

^^ +1 on the above post. (Sorry, man. Couldn't resist.)

[MadMan]

You sure? It really looks like a 7-segment. Also, aren't these the ones that aren't actually tubes? They're just light bulb filaments for the segments?

Originally Posted by Chip Chester

^^ +1 on the above post. (Sorry, man. Couldn't resist.)

LOLOLOL ok, that was pretty good. Made me laugh.

[jr_tech]

Originally Posted by MadMan

You sure? It really looks like a 7-segment. Also, aren't these the ones that aren't actually tubes? They're just light bulb filaments for the segment.

I think you're right...here is a similar device lit up on a project board:

https://m.youtube.com/watch?v=o-GVQp622Us

jr

[madlabs]

They are just light bulbs in segments. Vacuum, not gas filled. Used a lot in avionics. Nixie tubes were too fragile and require HV to light.

[init4fun]

Yea , I'm unfortunately sure about the display of only + , - , and 1 , because I saw the datasheet on all of the numitron tubes and indeed the 2020 is limited to those three characters only . The other numitrons , listed 2200 if I recall correctly , do have the digits 0 through 9 . There were plug in varieties and hard wired types that had different part numbers , in all I think there were maybe 6 different types listed .

[3Guncolor]

You might want to confirm the number on the tube matches the box.

[RDusel]

Once upon a time (1972) Heathkit produced a high end solid state tuner when SS was new. It was one of the first with a microcontroller controlling a precision oscillator and got high marks for it's reception and fidelity.
It used these numitron tubes to display the frequency.
Look up Heathkit AJ1510 and you can see them. The numitrons look neat but they are just low brightness bulb filaments and burn out after time.
I have one and had to replace a couple of the tubes.

[init4fun]

Originally Posted by 3Guncolor

You might want to confirm the number on the tube matches the box.

Even better , I should put my glasses on and read ALL the boxes instead of reading the number off of one box only , Thank You for prompting me to take a second look at them !

Come to find out , I have one each of "DR2000" , "DR2010" and of course the "DR2020" . The first two do have the full range of segments , one having also a decimal point explaining the difference in numbers even though they both do have the full segment compliment .

+1

[Electronic M]

+.8 - :d

[Chip Chester]

Best I can do is +199

[AdamAnt316]

Very cool! Numitrons were used in test equipment, as well as early digital tuners like the Heathkit AJ-1510. I believe they were also used in early digital gas pumps, and possibly some pinball machines as well (though some of those might've been Panaplex displays). Numitrons indeed technically qualify as vacuum tubes, unlike nixie tubes (which are filled with neon, so technically are "gas tubes").

I'm lucky to have a couple of sleeves of National-branded DR2010s. I've long been planning to build a clock or two using them, but have yet to get around to finishing the project. If you can get a few more 7-segment Numitrons (try here), you could use them to build this clock design or one of the other designs listed on that page. Good luck!
-Adam

[init4fun]

Thank You , I like that clock ! It's funny , I've got a couple of small (2") oscilloscope tubes that I saved for some clock projects , and now I've saved the clock you posted , if I ever actually get to building them I'll have a couple of pretty cool clocks . Your right that I'd have to get a few more Numitrons , and as in interesting side note I noticed that even though it's been said here that they are basically light bulbs , there is a getter ring with the accompanying silver getter deposit on the glass , something I've not seen in any other incandescent light bulbs .

[AdamAnt316]

Yeah, I've had the board for Sal's Numitron clock partially-built for a long time now. Just need to find a place to mount the 9-pin tube sockets, solder those umpteen diodes to their lugs, mount everything in place, and hopefully it'll keep time. In addition to this, I've amassed a number of nixie tubes, as well as a 5UP1 CRT which oughta make for a nice clock if I can find an o'scope tube driver able to manage a tube this large (most of the circuits I've seen seem to be suitable for 3" or smaller CRTs).

In addition to the various ongoing projects, I also have a couple of cool early digital clocks which were built by other people. I have an old B&F Enterprises nixie clock which was built from a kit circa 1972, and though it had many issues when I got it, most of its ills have been taken care of (I hope). I also have numerous Heathkit Panaplex digital clocks, though only one of them is currently working, a GC-1092D. Hopefully, I can get the other ones working, as well as another homebrew nixie clock I have which had been gutted for some of its parts before I got it. As you can probably tell, I have a thing for oddball clocks..........

[init4fun]

Kudos for you with the different clock thing , although I've always been mostly into tube radios I can appreciate clocks as a nice little side hobby if I ever get the time to build some .