Noun
A thermionic valve similar to a triode with the addition of a screen grid to improve the thermionic emission.
A dynatron.
A dual-gate MOSFET.
Source: en.wiktionary.orgBeam power tubes 6L6 tubes in glass envelopes main The beam power tube is usually a tetrode with the addition of beam-forming electrodes, which take the place of the suppressor grid. Source: Internet
But in a tetrode they can be captured by the screen grid (thus also acting as an anode) since it is also at a high voltage, thus robbing them from the plate current and reducing the amplification of the device. Source: Internet
Later tetrodes had anodes treated to reduce secondary emission; earlier ones such as the type 77 sharp-cutoff pentode connected as a tetrode made better dynatrons. Source: Internet
At certain values of plate voltage and current, the tetrode characteristic curves are kinked due to secondary emission. Source: Internet
However, the tetrode had one new problem. Source: Internet
In addition, as the tetrode carrier and peak tubes require very little drive power, a significant improvement in efficiency within the driver stage is achieved as well (317C, et al.). Source: Internet