The GN-5A (military code CV5351) is a large top-viewing Nixie tube produced by the British manufacturer STC and marketed under the “Nodistron” brand. It succeeds the GN-1 and GN-2 models, maintaining the same pinout and compatible electrical specifications. A distinguishing feature of the GN-5A is the faint bluish glow emitted by its illuminated digits, indicating the presence of mercury in the gas mixture which was absent from its predecessors. This mercury addition likely contributes to a significantly extended lifespan. Visually, the GN-5A closely resembles the GN-2, with the main external difference being the addition of a non-evaporative getter, a feature commonly found in later-generation Nixie tubes.
A variant of the GN-5A with a red-coated glass envelope was also available, designated as the GN-5.
Key Specifications
| Property | Description |
|---|---|
| Manufacturer | STC |
| Time period | Mid 1960s |
| Digit height | ~25mm |
| Envelope diameter | 40mm |
| Socket | B12A |
References
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