Definition: vacuum tube types

Following are the different types of vacuum tubes and the elements used to control the flow of current. See vacuum tube.

             ----- VACUUM TUBES ------
                  Triode       Pentode
 Elements    Diode      Tetrode

 Cathode       X    X      X      X

 Plate         X    X      X      X

 Control grid       X      X      X

 Screen grid               X      X

 Suppressor grid                  X