The grid, specifically the control grid, is an electrode positioned between the cathode and anode of a vacuum tube. By applying a small voltage to this wire structure, it creates an electrostatic field that regulates the much larger current of electrons flowing past it. Variations in the grid voltage produce proportional variations in the anode current, allowing the tube to amplify signals.
Check the bias voltage on the grid; if it goes positive, the tube will draw too much current and red-plate.
Also heard as
- control grid
Related terms
Vacuum tube
An evacuated glass or metal envelope containing electrodes used to control electron flow.
Triode
A three-electrode vacuum tube capable of amplifying electronic signals.
Cathode ray tube
A vacuum tube containing one or more electron guns and a phosphorescent screen used to display images.
Bias
A steady DC voltage or current applied to an electronic component to establish its resting operating point.