1. Heating Elements - Heating elements are typically made from metals like tungsten, molybdenum, or alloys of these metals. They provide the heat source for a variety of electrical applications, including lamps and vacuum tubes.
2. Cathodes - Cathodes are typically an electrode which is heated by the electrical current within a vacuum tube. It provides a path for the flow of electrons to travel in order to light a lamp or amplify an electrical signal.
3. Grids - Grids are typically made from metals like tungsten or molybdenum and are used to control the flow of current within the tube. They act as a valve of sorts and allow the tubes to amplify a signal or act as a switch in some cases.
4. Connectors - Connectors serve to ensure the electrical connections are solid and secure between components. They are often made from gold or brass, and are manufactured in varying sizes and shapes to suit a particular application.
5. Gases - Gases like argon, neon, or even krypton and xenon can be used within a tube to control the flow of electrons. The type of gas and pressure used will affect the output of a tube and allow it to be used for more intricate applications.
6. Filaments - Filaments are thin wires made from metals like tungsten, molybdenum, or nickel. They are wrapped around an element within a tube, and when arranged correctly provide electrons with a path to travel in order to cause a desired effect.