The Nixie Tube Clock

by Geoff
(Chapel Hill, NC 27707)

I have admired the nixie tube since first seeing it in the movie "The Shadow". They were installed as countdown indicators in the atomic weapon used to frighten New Yorkers after Shiwan Khan's psychic attacks begun. They were very antiquated in their appearance as orange, blinking numerals flicking ominously on and off. They also added to the art deco theme of the movie's design, being the obvious choice to show how new and peculiar electronic gadgetry was in the 1930s.

Years later, after remembering the countdown clock from the movie, I searched the internet to find out what these magnificent glowing tubes actually were. I learned that they were composed of a vacuum tube containing several cathodes in the shape of Arabic numerals. These cathodes, when energized with some medium-voltage direct current, would glow orange as they emitted electrons across a gap to the anode. These cathode devices were first fabricated in Germany in the late 1920s but only found use in the late 1950s when electronic numeral displays became high-demand items.

I also learned that there were several groups, both online and otherwise, that specialized in the collection and restoration of cathode ray vacuum tubes. Nixies are not really made anymore since they have been replaced by liquid crystal and the majority of remaining nixies are twenty or more years old having originated in former Soviet Bloc countries. Some of these preservation groups also specialize in construction and sale of nixie tube clocks built around steel chassis and a modern quartz timing circuit. Being an avid fan of the nostalgic/esoteric display method, I had to have one.

I again turned to the internet, finding several different dealers producing different types of clocks from different style nixie tubes. Some were very large, made from huge nixies intended for use on the East German rail system while others were small enough to be made into a wristwatch. I selected a sleek, stylized metallic design reminiscent of Art Deco period artwork and desk clocks. Chronotronix offered the IN-18 Nixie Clock which used large (1.5in tall) Russian-made tubes set in a polished chrome stainless steel case. It was a true work of art, and its large size effectively dominated any room it was in, calling attention to the ever changing (and quite bright) digits. It was easily adjustable and each tube was electronically driven separately to minimize voltage fluctuations that would affect constant brightness. It also came with a pair of gloves to handle the clock without leaving fingerprints.

Luckily the former supervisor in my lab knew of my interest and secretly planned to acquire one for me for my birthday in 2004. I soon learned that he shared my fascination for nixie tube clocks and we both shared in the joy the Chronotronix IN-18 brought us.