IN-18 nixie tube clock

A single tube clock using a Russian IN-18 vintage nixie tube

The entire clock, including its power supply, fits into a small bevelled acrylic cube machined for the purpose. The cube is prayed a metallic pewter. The top of the cube contains the socket for the tube.

I am rather fond of single tube clocks. It makes the best use of a vintage nixie tube and exercises all the cathodes.

To tell the time, the clock runs through the sequence of tens of hours, hours, tens of minutes and minutes before pausing and repeating the cycle. It is surprisingly readable.

The Russian IN-18 tube is one of the largest tubes available at sensible prices, but even in the last two years or so prices have doubled. Eventually sources will dry up altogether.

As I discovered, the geometry for the pins is very strange. The pins are on an 18mm circle at 24.5º intervals, which do not divide up equally into 360º, nor are any of the pins square on to front, back, left or right. I drilled a trial socket and when I was happy I used it as a template to drill my cube.

It's a tight fit inside the case, but it works.