Westinghouse Film - Electronics At Work - Electronic Tubes Explained
In this 1943 film by Westinghouse, the six basic functions of vacuum tubes are explained along with how each type of tube is used in industrial and military applications.
Rectify
Amplify
Generate
Control
Transform light into current
Transform current into light
This is a well done educational film with a 21minute run time. Provides a very nice tube tutorial for those of us who have grown up in the solid state / digital age taking some of the mystery out what these devices are all about.