# WWII RADIO OPERATOR VACUUM TUBE TRAINING FILM 77564

This WWII training film familiarizes radio operators with Vacuum Tubes. As the film explains, these are the devices used in radios that control electric current between electrodes in an evacuated container. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament. The grid and filament forming the tube are explained, as are some basic circuits, and a couple of electronics packages are shown. In electronics, vacuum tube, electron tube, tube (in North America), or valve (in Britain and some other regions) is a device that controls electric current between electrodes in an evacuated container. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament. This type is called a thermionic tube or thermionic valve. A phototube, however, achieves electron emission through the photoelectric effect. Not all valves/electron tubes are evacuated "vacuum tubes"; gas-filled tubes are similar devices containing a gas, typically at low pressure, which exploit phenomena related to electric discharge in gases, usually without a heater. The simplest vacuum tube, the diode, contains only a heater, a heated electron-emitting cathode (the filament itself acts as the cathode in some diodes), and a plate (anode). Current can only flow in one direction through the device between the two electrodes, as electrons emitted by the cathode travel through the tube and are collected by the…

- Kind: Film
- Genres: War, Industrial and advertising
- Archive: [Internet Archive](https://archive.org/details/77564VacuumTubes)
- Licence or status: none stated by the archive
- Who can watch: Teens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/ia/77564VacuumTubes?play=1)