WESTERN ELECTRIC 211-E TRIODE with GOOD FILAMENT
Here we have a very rare engraved base 211-E Triode. It is very clean and in good physical condition I have also checked the continuity between the pins with an ohm meter and between 2 pins reads about 9 ohms I am assuming that this is the filament.
Since the pins on the bottom show some oxidation I am assuming that the 9 ohms is a bit high and would be lower if the pins were cleaned and polished.
The inside of the tube is also clean, and the silver getter at the top is shiny and complete. There is some slight brownish marks (see photo)
Also someone has marked the base with an “12 Ef” this may be from the factory since it is very neatly done but it may not be stock since this tube is from the 1920’s it could of happened any time in the past 90 years.
this tube is currently on ebay –
Filament Current (maximum): 3A +/- .15A
Filament Voltage: 10V
Plate Voltage: 750 – 1000V
Average Plate Current for Plate Voltage 750V and Grid Voltage – 30V: 65 Ma
Average Plate Impedance: 3.5 K ohms
Mu: 11 – 13
Maximum Continuous Plate Watts: 65W