The S2035N is an RF pentode from 1933. This exhibit carries the Lotus Radio label as well. Lotus were a set maker and clearly labelled the valves they supplied.
The Lotus Radio label.
The rest of the envelope is plain zinc loaded screening paint. This is clearly from early production as the top cap has the screw terminal rather than the top hat. The anode is a cylinder of wire mesh topped with the mesh box.
A closer view. At this distance the depth of field is tiny and only the lower right of the image is totally in focus.
The balloon envelope is 50 mm in diameter, and excluding the B5 base pins is 138 mm tall.
Reference: Data. Type S2035N was first introduced in 1933. See also1933 adverts.
