If you have looked through my blog you'll know that I have a soft spot for tubes and tube technology. At a time when our understanding of electron mechanics and quantum theory was still in development the manufacture of advanced vacuum tubes was part science, part physics and part art.
Special purpose tubes were developed in their thousands to meet the needs of commercial, scientific and industrial applications. Their form and functions were as varied as the devices they were installed in. Sometimes tubes were developed to meet a specific need and sometimes new tubes were developed for applications not yet in existence.
The E1T tube is impressive even among special purpose tubes. It functions as a decade counter with an inbuilt display! Many years later it would take several chips and associated display circuitry to achieve the same result using solid state components.
This is a somewhat long introduction to the excellent article by Ronald Dekker on the people and the story surrounding the development of vacuum tubes technology in Holland and the E1T tube in particular.
If you have a moment take a look at The making of the E1T by Ronald Dekker and revisit a time when electronics, physics and art were brought together to create 'technology for a better tomorrow".