Editing Triode (section)

===Wider adoption===
The discovery of the triode's amplifying ability in 1912 revolutionized electrical technology, creating the new field of ''[[electronics]]'',<ref name="Nebeker" /> the technology of [[passivity (engineering)|active]] ([[amplifier|amplifying]]) electrical devices. The triode was immediately applied to many areas of communication. During World War I, [[amplitude modulation|AM]] voice [[two way radio]] sets were made possible in 1917 (see [[TM (triode)]]) which were simple enough that the pilot in a single seat aircraft could use it while flying. Triode "[[continuous wave]]" [[transmitter|radio transmitters]] replaced the cumbersome inefficient "[[Damped wave (radio transmission)|damped wave]]" [[spark-gap transmitter]]s, allowing the transmission of sound by [[amplitude modulation]] (AM). Amplifying triode [[radio receiver]]s, which had the power to drive [[loudspeaker]]s, replaced weak [[crystal radio]]s, which had to be listened to with [[earphones]], allowing families to listen together. This resulted in the evolution of radio from a commercial message service to the first [[mass communication]] medium, with the beginning of [[radio broadcasting]] around 1920. Triodes made transcontinental telephone service possible. Vacuum tube triode [[repeater]]s, invented at [[AT&T|Bell Telephone]] after its purchase of the Audion rights, allowed telephone calls to travel beyond the unamplified limit of about 800 miles. The opening by Bell of the first transcontinental telephone line was celebrated 3 years later, on January 25, 1915. Other inventions made possible by the triode were [[television]], [[public address system]]s, electric [[phonograph]]s, and [[talking motion picture]]s.

The triode served as the technological base from which later vacuum tubes developed, such as the [[tetrode]] ([[Walter Schottky]], 1916) and [[pentode]] (Gilles Holst and Bernardus Dominicus Hubertus Tellegen, 1926), which remedied some of the shortcomings of the triode detailed below.

The triode was very widely used in [[consumer electronics]] such as radios, televisions, and [[audio system]]s until it was replaced in the 1960s by the [[transistor]], invented in 1947, which brought the "vacuum tube era" introduced by the triode to a close.  Today triodes are used mostly in high-power applications for which solid state [[semiconductor device]]s are unsuitable, such as radio transmitters and industrial heating equipment. However, more recently the triode and other vacuum tube devices have been experiencing a resurgence and comeback in high fidelity audio and musical equipment.  They also remain in use as vacuum fluorescent displays (VFDs), which come in a variety of implementations but all are essentially triode devices.