This article is about the four-element vacuum tube. For other meanings, see Tetrode (disambiguation).
A tetrode is a vacuum tube (called valve in British English) having four active electrodes. The four electrodes in order from the centre are: a thermionic cathode, first and second grids, and a plate (called anode in British English). There are several varieties of tetrodes, the most common being the screen-grid tube and the beam tetrode. In screen-grid tubes and beam tetrodes, the first grid is the control grid and the second grid is the screen grid.[1] In other tetrodes one of the grids is a control grid, while the other may have a variety of functions.
The tetrode was developed in the 1920s by adding an additional grid to the first amplifying vacuum tube, the triode, to correct limitations of the triode. During the period 1913 to 1927, three distinct types of tetrode valves appeared. All had a normal control grid whose function was to act as a primary control for current passing through the tube, but they differed according to the intended function of the other grid. In order of historical appearance these are: the space-charge grid tube, the bi-grid valve, and the screen-grid tube. The last of these appeared in two distinct variants with different areas of application: the screen-grid valve proper, which was used for medium-frequency, small signal amplification, and the beam tetrode which appeared later, and was used for audio or radio-frequency power amplification. The former was quickly superseded by the rf pentode, while the latter was initially developed as an alternative to the pentode as an audio power amplifying device. The beam tetrode was also developed as a high power radio transmitting tube.
Tetrodes were widely used in many consumer electronic devices such as radios, televisions, and audio systems until transistors replaced valves in the 1960s and 70s. Beam tetrodes have remained in use until quite recently in power applications such as audio amplifiers and radio transmitters.
A tetrode is a vacuum tube (called valve in British English) having four active electrodes. The four electrodes in order from the centre are: a thermionic...
A beam tetrode, sometimes called a beam power tube, is a type of vacuum tube or thermionic valve that has two grids and forms the electron stream from...
A tetrode transistor is any transistor having four active terminals. There were two types of tetrode transistor developed in the early 1950s as an improvement...
Hugo Martin Tetrode (7 March 1895, in Amsterdam – 18 January 1931, in Amstelveen) was a Dutch theoretical physicist who contributed to statistical physics...
triodes used for amplification and switching. Additional electrodes create tetrodes, pentodes, and so forth, which have multiple additional functions made...
The KT88 is a beam tetrode/kinkless tetrode (hence "KT") vacuum tube for audio amplification. The KT88 fits a standard eight-pin octal socket and has similar...
a solid state version of the dynatron oscillator which normally uses a tetrode thermionic valve (vacuum tube). The tunnel diode showed great promise as...
was developed from the screen-grid tube or shield-grid tube (a type of tetrode tube) by the addition of a grid between the screen grid and the plate....
quantum Boltzmann gas are used in a number of cases including the Sackur–Tetrode equation for the entropy of an ideal gas and the Saha ionization equation...
at least in Europe. Because the beam tetrode design eliminated the tetrode kink in the lower parts of the tetrode's voltage-current characteristic curves...
amplifier and the ancestor of other types of vacuum tubes such as the tetrode and pentode. Its invention helped make amplified radio technology and long-distance...
Sackur–Tetrode equation, which he developed independently of Hugo Tetrode. His and Tetrode's names are also combined to name the Sackur–Tetrode constant...
Willem Danielsz. van Tetrode, known in Italy as Guglielmo Fiammingo (before c. 1530, Delft — after 1587), was a sixteenth-century sculptor of Dutch origin...
application as a power amplifier for audio frequencies. The 6L6 is a beam tetrode that utilizes formation of a low potential space charge region between...
mode, P-channel MOSFET Vacuum tube diode Vacuum tube triode Vacuum tube tetrode (pin letters are not part of the symbol) Vacuum tube pentode For multiple...
magnetic-core memory. Secondary emission can be undesirable such as in the tetrode thermionic valve (tube). In this instance the positively charged screen...
oscillator circuit which uses a negative resistance characteristic in early tetrode vacuum tubes, caused by a process called secondary emission. It was the...
(frequency conversion). The tetrode description, though accurate, does not replicate the vacuum-tube tetrode. Vacuum-tube tetrodes, using a screen grid, exhibit...
neither the term tetrode nor the tetrode valve as it is known today had yet appeared. The bi-grid differed from the later tetrode because the second...
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