Tube — Vacuum

Placed between cathode and anode to control the volume of electrons.

Introduced the grid for amplification.

A glass or metal container that prevents air molecules from disrupting electron flow. Common Types vacuum tube

Heated (white-hot) to "boil off" electrons via thermionic emission. Placed between cathode and anode to control the

Basic rectifiers, converting AC to DC.

Examples include "magic eye" tubes for signal display, thyratrons, and magnetrons. Key Technical Details and magnetrons. Key Technical Details