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Audion
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The Audion is an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest as a diode in 1906. Improved, it was patented as the first triode in 1908, consis
Triode Audion vacuum tube from 1908. The filament (which was also the cathode) was at the lower left inside the tube, but has burned out and is no lon
Triode Audion vacuum tube from 1908. The filament (which was also the cathode) was at the lower left inside the tube, but has burned out and is no longer present. The filament's connecting and supporting wires are visible. The plate is at the middle top, and the grid is the serpentine electrode below it. The plate and grid connections leave the tube at the right.
An Audion radio receiver by de Forest. The Audion tubes were mounted upside down to prevent the delicate filaments from sagging and touching the grids
An Audion radio receiver by de Forest. The Audion tubes were mounted upside down to prevent the delicate filaments from sagging and touching the grids. This receiver provided the ability to choose operation of either one of the two provided detector tubes.
Audions and early triodes developed from them, 1918 Bottom row (D): De Forest Audions and oscillaudions Third row (C): Pliotrons, developed at General
Audions and early triodes developed from them, 1918 Bottom row (D): De Forest Audions and oscillaudions Third row (C): Pliotrons, developed at General Electric by Langmuir Second row (B): triodes developed at Western Electric which bought the rights from de Forest in 1913. Top row (A): French triodes. The French government gained the right to manufacture Audions in 1912 when de Forest failed to renew his French patents for lack of $125.
The first Audion AM radio transmitter, built by Lee de Forest and announced April, 1914
The first Audion AM radio transmitter, built by Lee de Forest and announced April, 1914
Triode
Videos
A triode is an electronic amplifying vacuum tube consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate.
Audion
…detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest as a diode in 1906. Improved, it was patented as the first triode in 1908, consisting of an evacuated glass tube containing three electrodes: a heated filament (the cathode, made out of tantalum), a grid, and a plate…
Examples of low power triodes from 1918 (left) to miniature tubes of the 1960s (right)
Examples of low power triodes from 1918 (left) to miniature tubes of the 1960s (right)
ECC83, a dual triode used in 1960-era audio equipment, showing the orange glow of the hot cathode.
ECC83, a dual triode used in 1960-era audio equipment, showing the orange glow of the hot cathode.
3CX1500A7, a modern 1.5 kW power triode used in radio trans­mitters. The cylindrical structure is a heat sink atta­ched to the plate, through which ai
3CX1500A7, a modern 1.5 kW power triode used in radio trans­mitters. The cylindrical structure is a heat sink atta­ched to the plate, through which air is blown during operation.