Technical Details
A thermionic valve (also known as a vacuum tube) is an electronic device consisting of an arrangement of electrodes in a vacuum within an insulating, temperature-resistant envelope. Basic thermionic valves resembled an incandescent light bulb. Prof. J. A. Fleming, chief scientific advisor to the Marconi Company from 1900, invented the diode, a special kind of thermionic valve, in 1904. The valve was initially experimental, despite its massive advantages over the crude crystal sets: it was more sensitive, could carry speech, and enabled higher speeds of Morse code transmission and reception. These valves led to more compact, mobile, and powerful Wireless Telegraphy sets. A triode is a type of valve with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electrical amplification device and still remains in use for amplification purposes.