Uploaded January 2018 | Updated September 2026, 2 weeks ago
Another weird tube - an extra large acorn tube! It is taller than a 955 and skinnier than a 1630. This very much looks like a power triode, and the only markings it has is a cryptic 21-203. Clearly a prototype or lab made device - but from who? When? Where?
Another weird tube - an extra large acorn tube! It is taller than a 955 and skinnier than a 1630. This very much looks like a power triode, and the only markings it has is a cryptic 21-203. Clearly a prototype or lab made device - but from who? When? Where?
