There is an error in tha datasheet of this tube where is stated that it has a B5 base. This tube (other brochures) has a B4 base and the tube is heated direct.
Bibliografia
- - Manufacturers Literature 1935
Universal Vade-Mecum, Electron Valves and Semiconductor Devices Section 138, p. 186
Röhrencodex , Röhren-Taschenbuch 1950 23000 Röhren
Röhren-Vademecum; P.H. Brans; Antwerpen
W306_Marathon: rtt
Anonimo 10 Collezionista
Just Qvigstad
W306_Marathon: own collection
Peter den Boer † 2025
