Fleming Valve

Valve

Valve covered externally with copper gauze shield for protection from external electric fields. Filament is small and probably of tantalum. Anode consists of a flat metal plate placed close to one side of filament. Production version with copper flat plate anode with external copper wire gauze screen and bayonet cap. c 1908-1910. Probably metal filament.
Valve covered externally with copper gauze shield for protection from external electric fields. Filament is small and probably of tantalum. Anode consists of a flat metal plate placed close to one side of filament. Production version with copper flat plate anode with external copper wire gauze screen and bayonet cap. c 1908-1910. Probably metal filament. This is most likely the same '4' valve referred to in Fleming's experimitation notes in Special Collections. If so, then the valve was recieved on 24 June, 1908. Asbestos Inspection - Non-Asbestos. (this number recorded twice - mistake by inspector?)

Marconi's Wireless Telegraph Company

circa 1908 to circa 1910

copper, glass

- Thermionic Valve and its Development in Radiotelegraphy and Telephony, 69

Electronic and Electrical Engineering

LDUSC-EE-2

1

UCL Science and Engineering Collections