N_Western

Following the work done for the US Army signal Corps on the "P" or VT-3 tube, Western Electric engineers designed a small tubular tube with a concentric element assembly and this was the first "N" tube. It was made in November 1919 and was baseless, with a "butt seal" to allow entry of the four lead-in wires. The tube was later given a bakelite base and was redesignated 215A.

Hendrik Johannes van der Bijl was the engineer who develped the tube, which was called the "Peanut Tube" for its very small size. van der Bijl deduced the fundamental functioning relationships of triodes and that, won a post at the Western Electric Company as senior Research Physicist until the publiction of the book "Theory of the Thermionic Tube and its Applications" in 1920 (EE).

The "peanut tube" was also produced in Canada and STC (Standard Telephones and Cables Ltd, London) produced the 215A as the 4215A and as 4215AB wth asttandard 4 pin B4 or European bse.