[RicoElectrico]

> Nixie tube is a tiny electrical tube with filaments in the shapes of all the digits stacked one on top of another, and it displays the desired digit by making just that filament glow

Lol, no. That's a Numitron (although they were 7 segment)

[tasty_freeze]

You are confidently incorrect.

https://ethw.org/Nixie_Tubes

[RicoElectrico]

Filament implies it is resistively heated, per tube terminology. Nixie is essentially a neon lamp, specially shaped, whose cathode is cold.

[adrian_b]

You are of course right, but you should have pointed out that the text quoted by you was not 100% wrong, because the ten cathodes have indeed the forms of the ten digits and they are stacked one above the other.

The only wrong parts were that the cathodes are not filaments and the cathodes themselves do not glow.

The Nixie tubes are filled with neon at low pressure and the electric discharges through them produce the so-called negative light, i.e. where the luminescent gas is confined around the cathode. Therefore the negative light takes the shape of the cathode. The cathodes are not glowing, but they are surrounded by glowing neon gas.

In my opinion, negative light, which comes from an apparently empty space, looks somehow more beautiful than solid light emitters, like an incandescent filament or a fluorescent lamp (like VFD, i.e. vacuum fluorescent displays; display tubes with incandescent filaments or with fluorescent segments were alternatives to Nixie tubes, until all of them were replaced by cheaper LEDs and LCDs).

The neon tubes that were used in advertising for making letters or other shapes, use positive light instead of negative light, i.e. where the luminescent gas occupies most of the glass tube, away from the electrodes, so giving various shapes to the glass tube provides various shapes of the visible light, regardless of the shapes of the electrodes (unlike for negative light, where the shape of the cathode matters, while the shape of the glass tube is irrelevant).

[master-lincoln]

your article says it's a gas discharge vacuum tube, so no filament. You seem to be confidently incorrect too.

[lightedman]

Multiple types of gas discharge vacuum tubes use a filament of some sort for excitation, be it a coil or grid.

[adrian_b]

Nixie tubes, like all gas-discharge tubes with negative light, do not use any filament.

A filament could be needed with a higher pressure gas, to emit electrons that would ionize the gas, to facilitate the initiation of a discharge. A filament might also be needed sometimes when the gas is a metal vapor, like mercury vapor or sodium vapor, in order to heat and vaporize the metal, though that is more commonly done by adding some noble gas, like neon, to cause a preliminary discharge that heats the metal until enough vapor is present, which allows the initiation of the main discharge.

[lightedman]

"The glass tube contains a wire-mesh anode and multiple cathodes," - per Wiki

That's filament. A construction of filaments, but a filament nonetheless.

[master-lincoln]

I concur

[drfuchs]

Also, Nixie Tubes were absolutely not “tiny.” Typically, they were about the same size as a vacuum tube you’d find in the back of your radio or TV. They were universally used on electronic equipment; less so on consumer devices.