|tetrode (tět'rōd') Pronunciation Key
A four-element electron tube containing an anode, cathode, control grid, and additional electrode called the screen. They function in the same manner as triode, but are more effective at higher frequencies due to the effect of the screen. See more at screen, See also pentode.
vacuum-type electron tube with four electrodes. In addition to the cathode filament, anode plate, and control grid, as in the triode, an additional grid, the screen grid, is placed between the control grid and the anode plate. The screen grid acts as an electrostatic shield to protect the control grid from the influence of the plate when its potential changes. Although the pentode has replaced the tetrode in most vacuum-tube functions, a specially designed tetrode, called the beam-power tube, has found extensive use in power amplification
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