Today built-in Nixie clocks tubes are found in old warehouses or removed from discarded equipment. Usually the built-in Nixie clocks tubes are approximately about 40 years old. Stocks of Nixie tubes are difficult to obtain and are expensive. These are rare.
Nixieclocks.ch installs right now unused tubes.
On the back of the Soviet tubes are printed information on the type, manufacturer, year of manufacture and quality marks.
However, the imprint is not always well preserved due to the age of the tubes. These tubes have good prints.
Tubes produced by the same manufacturer are not always exactly identical.
In the left Nixie tubes, the anode is made of a finer structure. The tips of tubes ablated by glassblowers are of different lengths.
The manufacturer of the Nixie clock checks the function of tubes and is choosing identical tubes for installation in a clock.