Summary

T250 triode, transmitting. Made by Marconi. circa 1922. Filament voltage was 12.5 volts at 5.5 amp. anode voltage was 4000 volts. total emission was 450 ma. impedence was 17000 ohms. amplification factor was 20. Used for radio transmission.

Physical Description

Spherical glass bulb with cylindrical ends, supported vertically and mounted on a stand with display label. The external leads are fitted with glass beads. Exhaust tip on side. No base, internal connections are brought to outside by pinched glass seals.

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