# What determines Nixie tube digit stack order?

I recently watched a video of Nixie tubes being built and another user had asked what determines the stack order of the digits in front of the anode. I searched around trying to find the answer but I couldn't find anything other than several sites with a carbon-copy response that barely mentioned their ordering at all. Originally I assumed it might have something to do with visibility of each digit behind other digits but the order seems almost opposite to me if that were the case. Then I assumed it might have something to do with surface area of a digit and its distance to the anode but again the ordering didn't quite seem to make sense to me if that were the driving factor. Even the Wikipedia page itself shows examples of different stack orders in its pictures of tubes. So my question here is: What determines the order in which the digits are stacked in the Nixie tube assembly?

One such arrangement is 6 7 5 8 4 3 9 2 0 1 from front (6) to back (1).[7][8] Russian NH-12A & NH-12B tubes use the number arrangement 1 6 2 7 5 0 4 9 8 3 from back to front, with the 5 being an upside down 2.

• That's a cool question, I want to know the answer too! – zeta-band Nov 15 '18 at 20:09
• i think that the person that designed the Nixie tube decided the stack order ..... it appears to be a matter of aesthetics – jsotola Nov 15 '18 at 20:49

It might help taking a look at the (round) pinout. At least 6 7 5 8 4 3 9 2 0 1 clearly corresponds to going forward on one side and backward on the other, namely sequentially on a circle. The Russian Nixies are oval: check out this link for their overall arrangement and pencil in the various numbers at their respective pins. I think you'll find that again this is mostly determined by proximity to pins.

• Thanks for the reply. Using 6 as a starting point and walking away alternating on both sides definitely yields that pattern! Thank you! – HDL_CinC_Dragon Nov 16 '18 at 7:25

If it can help, this is the French Wikipedia page of Nixie tube (Tube Nixie)

Un avantage des tubes Nixie est que ses cathodes ont des formes dessinées de façon à respecter la typographie, à être lues facilement. Dans la plupart des modèles, elles ne sont pas placées dans l'ordre numérique de l'arrière vers l'avant, mais disposées de façon que les cathodes situées en avant d'une cathode illuminée l'obscurcissent le moins possible.

Translation:

One advantage of Nixie tubes is that their cathodes have shapes designed to respect typography, to be read easily. In most models, they are not placed in numerical order from the back to the front, but arranged so that the cathodes in front of an illuminated cathode obscure it as less as possible.

• As this is from a wikipedia article, can you link to the source that article uses? – Hearth Apr 25 '19 at 13:51