Marconi Scientific Instrument radio using DEV valves скачать в хорошем качестве

Marconi Scientific Instrument radio using DEV valves

I have uploaded several videos of the Marconi radio from 1922. In these videos the radio is using bright emitter valves (three V24 and one R-type). Working bright emitter valves are very rare (their lifespan was considerably less than a dull emitter, typically between a half and a tenth). Because of this collectors rarely use them because of the danger of burning them out. However, in the case of the V24, the DEV dull emitter valve is rarer, as it was only released in 1923 and was little used. The DEV used a thoriated tungsten filament. Compared to later dull emitters using an oxide-coated filament it is still fairly bright, but the glow is nothing compared to the V24!