Nixie Clocks: How They Work and How to Choose One

A nixie clock shows the time with nixie tubes: vintage glass tubes in which each digit glows orange. Here is how these clocks work, and what to look at before buying one.

How a nixie clock works

A modern nixie clock combines nixie tubes with up-to-date electronics: a microcontroller that drives the display, a quartz crystal or a GPS/WiFi signal for accurate time, and a small high-voltage supply that turns the safe low-voltage adapter into the roughly 170 V the tubes need. The result is a vintage display with modern features.

What to look for when buying

The tubes

Number of tubes: four tubes show hours and minutes; six add the seconds. Single-tube clocks show the time digit by digit.
Size: compact tubes such as the IN-14 suit a desk; large tubes such as the IN-18 or ZM1042 are readable across a room.
Origin: most tubes are new old stock – vintage, never used. A few, like the Dalibor Farny R568M, are hand-made today.

Features that protect the tubes

Anti-cathode-poisoning routine that regularly cycles every digit
Night mode to dim or blank the display at night
Motion sensor that switches the tubes off when the room is empty

Timekeeping and comfort

Accurate time: quartz crystal, with optional GPS or WiFi synchronisation
A daylight saving time button, so you do not have to reset the clock twice a year
Backup that keeps the time through short power cuts
Programmable backlight if you like colour under the tubes

Build, safety and support

Enclosed electronics and a mains adapter suited to your country
A real warranty and a maker you can contact
A case you like: clear acrylic or plexiglass shows the electronics, steel gives an industrial look, aluminium a modern one

Which Nixie Boulevard clock?

A first nixie clock or a small desk: the desk clock with four IN-14 tubes.
Big digits at the best price: the IN-18 clock in clear acrylic.
A centrepiece: the museum-grade IN-18 clock or the IN-18 in brushed steel.
Something different: the ZM1042 clock or the single-tube Solitube.

Every clock is assembled by hand in Paris, ships worldwide and comes with a 1-year warranty. Still hesitating? Ask me.