Everything you need to know about Nixie tubes
Everything you need to know about Nixie tubes.
Nixie tubes are vacuum tubes made in 1970's to 1990's in Russia, Czech Republic, USA, Germany, China, etc. They were out of production since 1990's, after LED technology took over.
Since they are out of production since 1990's, they become collectables. Their prices have been going up day by day. If you own a clock, and want to have a few tubes as backup, then buy the tubes now if you can find them (usually eBay is a good place to start).
Orange is the only color. We put RGB LEDs underneath each tube to give them a colorful look. These LEDs can be switched off, or changed to different colors using the remote control.
How long can they last? Nixie tubes usually last for 5~7 years. And with the automatic on/off feature with our clocks, they can last for 10~15 years or even longer.
The black dot is called getter. When the tubes were evacuated during the manufacturing process, a tiny portion of air was left in the tube when it's sealed close. The black dot was intentionally added to react with the residual air/oxygen so that no oxygen will remain in the tube. If there were oxygen, when the filament lights up, it will be oxidized by oxygen, which should be avoided. Therefore, when the black dot is seen inside a tube, it indicates the tube still has good vacuum in it. If the black dot is gone, the tube may have leakage and is already broken, although sometimes it's not easily seen.