Transmitting Valve Radio Part, Possibly by GEC-Osram Valve Co. Ltd., London, pre-1919

Initially thought to be made by Marconi-Osram Valves and datable to early 1920s. Subsequently considered to be by GEC-Osram Valves, and hence pre-1919. GEC made valves at Osram Lamp Works in Hammersmith, London until Osram merged with Marconi to form Marconi-Osram Valves in 1919.