Old-style TV sets and other electrical products made between the 1930s and 1970s contain vacuum tubes for creating, amplifying and modifying electrical signals. The tubes function by controlling the electron movement in a low pressure environment, such as low pressure gas or in a vacuum. A vacuum tube consists of a glass – sometimes metal or ceramic – tubular envelope with electrodes contained in a vacuum atmosphere. To test a vacuum tube use one of the many vacuum testers available on the market. Tips Warnings Writer Bio
