First sample "nixie tube"

Estimate reading time: 2 minutes

So, there is my first nixie tube. I was really eager to make anything sealed, so I didn’t pay much attention to details and lifetime of the tube. There are two (stainless steel) cathodes – “0” and “7”, a small piece of stainless steel sheet is used as the anode. Distance of the cathodes to the anode is different, so behaviour (breakdown voltage, current needed) is different – it is easier to light the “7”, the “0” gives uneven glow. However, when I fill it on the manifold, both striked nicely, I think that some moisture from the glass was evaporated into tube during the tip-off.

Some data:

  • 38 torr total pressure
  • 0.2 torr of Argon
  • striking voltage for the “7” somewhere around 320V
  • 9k1 resistor used
  • digit size around 25mm
  • it has no getter
  • it is not baked, just the glass envelope was heated for a few minutes with hair dryer