The Valve Technology Milestone Timeline
Courtesy to the
National Valve Museum
1640 The first vacuum. Otto von Guericke's air pump 1643 The barometer first demonstrated by Evangelista Torricelli 1654 Magdeberg Hemispheres a demonstration of the force of air pressure 1672 Improved air pump and treatise on vacuum experiments published. 1716 Jacob Hermann suggests that gas pressure is proportional to density and to the square of the average velocity of the gas particles in motion 1811 A principle stated in 1811 by the Italian chemist Amedeo Avogadro (1776-1856) that equal volumes of gases at the same temperature and pressure contain the same number of molecules regardless of their chemical nature and physical properties 1855 Johann Geissler produces a mercury vacuum pump and with it he produces the first good vacuum discharge tubes 1856 Karl Kronig suggests that gas molecules in equilibrium travel in straight lines unless they collide with something 1858 Julius Plucker demonstrated that magnetic fields bend what later became known as cathode rays. 1860 Joseph Swann patents the the carbon filament incandescent lamp that operates in a partial vacuum 1862 Geissler-Topler mercury vacuum pump developed 1865 Hermann Sprengel develops the mercury drop pump 1870 Sir William Crookes vacuum pumping system 1871 C F Varley suggests that cathode rays are particles 1871 Sir William Crookes advances the idea that cathode rays are negatively charged particles 1874 G R Carey invents the photo-electric cell 1876 Sir William Crookes demonstrates pumping by chemical getters 1876 L von Babo develops a self-recycling Sprengel vacuum pump 1876 Alexander Graham Bell invents and demonstrates the telephone 1879 Thomas A Edison files US patent on high vacuum carbon filament incandescent lamp 1879 Sir William Crookes develops the Crookes Tube, an early form of cathode ray tube 1879 Edison improves the self-recycling Sprengel-Geissler mercury vacuum pump 1880 Apparatus for evacuating Edison's electric lamps. Based on Crookes design 1883 Thomas A Edison first observes thermionic emission in a vacuum 1883 John Ambrose Fleming presents a paper on the 'molecular shadow' to the Physical Society of London on May 26 1883 In October 1883 the amalgamation of Edison Electric Light Co Ltd and Swan Electric Lighting Co to form Edison and Swan United Electric Light Co. Ltd. 1887 Sir William Crookes performs the Maltese Cross experiment 1889 Jonathan Zenneck improves Braun's CRT and adds time base deflection 1889 The British General Electric Co. Ltd was formed 1885 Sir William Preece duplicates Edison's experiment, makes quantitative measurements and presents a paper to The Royal Society 1886 Eugen Goldstein observes 'canal' rays (German = kanalstrhlen}. So called because they were emitted through a hole in the cathode. 1890 A C Cossor Ltd was formed. 1891 George J Stoney suggests the name of electron for cathode ray particles 1896 Mallgnani Corp demonstrates the use of phosphorus gettering 1896 The British Thomson-Houston Co. Ltd. was formed 1897 Sir Joseph Thomson discovers 'corpuscles' later called electrons 1897 Guglielmo Marconi sets-up in July 1897 the Wireless Telegraph and Signal Company Limited to commercially exploit his patents 1899 The British Westinghouse Electrical and Manufacturing Co. Ltd was formed. This later became the Metropolitan-Vickers Co. Ltd, (Metrovick) 1900 James Dewar builds a cryosorption pump using activated charcoal and liquid air 1900 John Ambrose Fleming becomes scientific adviser to Marconi's company 1901 W C Roentgen wins Nobel prize for Physics for discovery of x-rays 1901
Gugliemo Marconi transmits signal from England to North America 1901 Richardson produces an equation for the emission of electrons from incandescent metal filaments 1901 Peter Cooper Hewitt develops the fluorescent lamp 1902 Georges Claude builds the first neon lamp 1902 E Weintraub develops the mercury arc lamp and rectifier 1902 Charles Proteus Steinmetz files a patent on mercury vapour lamp with halide salts to improve colour 1902 Peter Cooper Hewitt develops the mercury vapour lamp 1902 A C Cossor Ltd make the first British examples of Braun's CRT 1903 Harris J Ryan builds magnetic deflection CRT's 1904 Arthur Wehnelt publishes details of the oxide coated hot cathode CRT 1904 January 1904, Arthur Wehnelt patents a diode. The patent does not mention use for rectification of RF. The device is described in connection with charging accumulators 1904 October 1904,
Sir Alexander Fleming produces rectification of RF in a valve. Valve history begins 1904 November 16 1904, Sir Alexander Fleming applies for a patent on the Oscillation Valve, later known as the Thermionic Valve and Fleming Diode. 1905 Philip Eduard Anton von Lenard wins Physics Nobel prize for Cathode Rays 1905 Wolfgang Gaede makes rotary mercury-sealed mechanical vacuum pump 1905 Albert Einstein explains the photoelectric effect 1906 W Voege and Rohn build the thermocouple vacuum gauge 1906 Lee de Forest invents the Audion (triode) as a sensitive detector 1906 Dieckmann, Glage, Rosing, Campbell-Swinton propose the use of the Braun tube to display television images 1908 Fleming replaces the carbon filament in his valve with a tungsten filament. This is before a process of making ductile tungsten had been devised 1909 Otto von Baeyer develops the ionisation vacuum gauge 1909 Robert Milikan measures the charge on the electron by the oil drop experiment 1909 Guglielmo Marconi and Carl F Braun win Physics Nobel prize for wireless telegraphy 1910 Pfeiffer Co produce the rotary oil-sealed mechanical vacuum pump 1910 Georges Claude demonstrates the neon lamp in public 1910 German telephone relay soft valve by Leiben-Reiz 1910 The early production
Audion's looked like this 1911 Edwin H Armstrong invents the regenerative circuit 1911 'Doc' Herrold begins first radio broadcast service in San Jose California 1911 Henry Round of the Marconi company commences work on the design of a diode valve 1912 Wolfgang Gaede develops first theory and experiment on the molecular-drag vacuum pump 1912 Irving Langmuir produces gas filled incandescent lamp 1912 Lee de Forest makes the first valve amplifier 1912 H M Fassenden develops the Heterodyne receiver 1913 Wolfgang Gaede first diffusion pump using mercury 1913 A Dufour develops a high voltage, continuously pumped CRT and records directly onto photographic plates 1913 John Johnson and H J Van der Bijl develop the first commercial CRT. Western Electric 224-A 1913 Marconi receiver with Captain Round's C valve 1913 Captain Round's T transmitting valve developed 1913 Saul Dushman produces a 40 kV vacuum rectifier 1913 W D Coolidge produces a High Voltage X-ray tube 1914 ATT purchase licence from de Forest in August 1914 1914 Marconi files suit against Lee de Forest over triode 1914 AEG-Telefunken develops standardised valves for radio reception. EVN94 and EVN129 1915 Edison and Swan Co. produce Round valves for the Marconi Co. 1915 GE in America begin production of Pliotrons (triodes) 1915 In France the first hard vacuum triode was made. During the war over 100,000 were made by the companies Metal and Fotos 1915 Western Electric patents the indirectly heated cathode 1915 October 1915 Cunningham develops the tubular Audion 1916 Lee de Forest builds tubular Audions.
See DV5 1916 The White soft valve produced. This has been developed by a British team working at the Cavendish Laboratory under the direction of J J Thomson 1916 Siemens and Halske in Germany develop the Type 'A' vacuum tube. About 50,000 are subsequently made 1916 A British version of the French valve was introduced. This was the
R Type 1916 The British Thomson Huston Co. commence making R Type valves for military use 1916 GEC (Osram) commence making R Type valves for military use 1916 Irving Langmuir develops a high-speed diffusion pump and all-metal condensation pump 1916 The Edison and Swan United Electric Light Co. Ltd. changes name to Edison Swan Electric Co. Ltd. 1914 ATT purchase de Forest's patent for the triode 1917 The Metropolitan-Vickers Co commences production of the
R Type 1917 July 3rd 1917, F Lowenstein's patent for negative bias 1919 October 1919. Marconi and GEC set up a joint company to manufacture valves. This was the Marconi-Osram Valve Co. Ltd. Later known as M-OV 1920 In September Capt. S R Mullard forms the Mullard Radio Valve Co. Ltd. 1920 Edwin Howard Armstrong invents the superhet receiver 1920 Irving Langmuir develops the thoriated tungsten filament 1920 Wolfgang Gaede develops the box pump 1921 Albert Einstein is awarded the physics Nobel prize for the photoelectric effect 1922 Mullard introduce the
ORA general purpose valve 1922 Cossor introduce the
P1 its first valve design post WW1. The electrode shapes avoided patents held by others 1922 On the 14th Novenber 1922 the
BBC went on the air from 2LO in London 1923 Robert A Milikan is awarded the physics Nobel prize for measuring the charge on the electron 1923 Lee de Forest introduces DV/DL tubular Audions.
See DV5 1923 M-OV introduce Captain Round's
DEQ high impedance detector 1924 L T Jones and H G Tasker demonstrate electrostatic focusing of a CRT with magnetic deflection 1924 Lisa Meitner of Germany discovers the radiationless electron transition known as the Auger effect. Named after Pierre Auger of France who discovered the effect in 1926.
See Augetron 1925 Bakelite based valves with the evacuation 'pip' concealed within were introduced 1926 Mullard introduce the first series of their PM valves.
See The Azide Process 1926 Loewe vacuum 'integrated circuit' multi valves introduced 1926 Farnsworth image dissector produced 1926 M Siegbahn introduces the disk type of molecular drag pump 1927 Philo T Farnsworth demonstrates an all-electronic television system in San Francisco 1927 Kenjiro Takayanagi demonstrates a gas focused oscillograph CRT to display television images 1927 In the UK the
S625 the world's first screened grid valve is produced 1927 May 1927, the landmark UX280 rectifier was introduced. This was subsequently manufactured for over 50 years 1927 Harold S Black discovers the benefits of negative feedback 1927 Albert W Hull builds the first Thyratron 1927 Friedrich Meyer, Hans J Spanner and Edmund Germer, in Germany, patent the high-pressure metal vapour UV and fluorescent lamp 1928 The
B5 base was introduced 1928 The Mullard company introduce the first Pentode to the UK market 1929 Kenneth C D Hickman develops low vapour pressure synthetic oils 1929 Cecil R Burch produces a gas diffusion pump employing low vapour pressure oils 1929 Complete amateur radio station with one valve transmitter and one valve receiver 1929 Manfred von Ardenne demonstrates an all-electronic television in Berlin 1929 Farnsworth electron multiplier developed 1929 Vladimir K Zworykin files a patent on the kinescope. Zworykin later developed the Iconoscope camera tube 1930 The Mazda
AC/Pen, introduced in 1930, was the first technically successful indirectly-heated power pentode capable of enough output to drive a moving-coil loudspeaker at good volume 1931 The external metalising of valves was introduced. Generally the metal was painted for protection. Red, Gold or Grey. 1931 National Union in the USA produce the first valves for car radios 1932 Alan B Du Mont starts to apply CRT's to television 1933 The
B7 base was introduced 1933 Westinghouse introduce a mercury-arc rectifier, the Ignitron 1933 E H Armstrong announces frequency modulation 1934 The
B9 base was introduced 1934 In the USA the 6.3 Volt filament is adopted as standard for both AC and DC filaments and heaters 1934 The GE
6E5 'Magic Eye' tuning indicator is introduced. RCA produce 6E5 in 1935 1934 The introduction of miniature Acorn valves for VHF.
See 955 1934 In the UK M-OV introduced the
Catkin range of valves with external anodes 1935 Wolfgang Gaede produces the gas ballast pump 1935 Kenneth C D Hickman produces a fractionating oil diffusion pump and associated oils 1935 RCA introduce the
IO base with the launch of the metal tube valve
6L7 1935 RCA nine original valves appear in the RCA metal valve family 1935 Watson Watt demonstrates that
aircraft reflect radio waves 1935 John Logie Baird demonstrates a 700 line high resolution television system 1935 Oskar Heil patents the field effect transistor. The device, however, did not work 1936 The world's first regular television broadcast by the BBC employing the EMI electronic system 1936 Mahn and Mecalf present a paper on velocity modulated valves. The key principle within the klystron 1937 At Stanford University the Varian brothers produce the first working Klystron 1937 C M Van Alta produces a diffusion pump with a pumping rate in excess of 100 litres per second 1937 L Malter demonstrates a multi-stage, self fractionating diffusion pump 1938 Mazda introduce the
MO in the UK as an alternative to the International Octal 1939 RCA and Du Mont demonstrate Television at the NY World's Fair 1939 The Loctal or
B8B was introduced in America 1939 The Philips introduce the all glass valve and with it the
B9G base 1939 The first all-glass valve for use above 30 MHz was produced. The
EF50 played a major part in early Radar 1939 The
B7G all-glass valve base was introduced in America. Its introduction to the UK was in 1947 1940 February 21st 1940 John Randall and Harry Boot make operational the cavity magnetron at Birmingham University 1940 On September 6th 1940 Sir Henry Tizard takes the cavity magnetron to the USA. This is one of the most secret inventions of the war 1940 In September 1940 the first RDF system using a
cavity magnetron is made in the UK 1940 In the USA the first all glass B7G 1.4 Volt miniature valve is introduced. This was the
1R5 1941 In America the 525 line system is approved by the FCC for commercial black and white broadcasting 1941 A UHF oscillator is made using Acorn valves.
See 955 1941 The UK government introduce the common valve (CV) lists to streamline procurement and increase flexibility in sourcing the valves required by all branches of government especially the military 1942 Rudi Kompfner at Oxford University produces the first travelling wave tube 1943 Dr Tommy Flowers builds the
first electronic computer for code breaking at Bletchley Park 1943 Percy Spencer of the Raytheon Co designs the laminated anode cavity magnetron which increased production rates 1945 Double triodes 1947 Bardeen, Brattain and Shockley demonstrate the first semiconductor amplifier 1947
B7G used on UK valves for the first time 1948 F C Williams describes the use of a CRT as a digital memory 1948 The B8A 'Rimlock' valve base is introduced 1948
B9A based all glass double triodes
12AU7,
12AX7 and
12AT7 are introduced 1949 Valve memory is introduced 1950 October 3rd 1950 the transistor is patented 1950 RCA demonstrate the shadow mask colour TV tube 1952 Ring getter with U-shaped cross section for valve manufacture is introduced 1953 B8A 'Rimlock' valves of all glass construction are introduced in the UK 1954 Mullard introduce the
EL34 25 Watt dissipation audio output pentode 1954 Texas Instruments produces the first silicon transistor 1957 The Nixie display tubes are introduced 1958 Elmer Fridrich and Emmett Wily file a patent application on the tungsten halogen lamp 1958 Varian Associates introduce the 'modern' Vacsorb cryosorption pump 1958 The IMB 709 was introduced. This was the last major valve computer and featured magnetic core memory 1959 IBM 7090 introduced, this is the world's first all transistor computer 1959 The Varian Klystron VA842 introduced. This multi-cavity liquid-cooled Radar klystron is the largest documented production klystron 1960 Varian Associates Inc. produce the 1000 Litre per second Valcon pump 1960 Ross Aiken develops CRT for aircraft and 14 inch thin CRT 1960 The Nuvistor is developed.
See 6CW4 1960 Ali Javan invents the Helium-Neon gas discharge laser 1961 C H Kruger and A H Shapiro unveil statistical theory of turbo-molecular pumping 1961 Varian Associates Inc produce very large sorption pumps for roughing large chambers 1961 Gilbert Reiling files a US patent for 'modern' metal-halogen incandescent lamp 1961 William R Wheeler introduces the UHF metal-gasket captured step-seal 1962 Fairchild Semiconductors produce the first integrated circuit 1962 Varian VA126 high power travelling wave tube introduced 1968 July 1968, Robert Noyce and Gordon Moore founded Intel 1968 A Y Cho
et al develop molecular-beam epitaxy 1969 K H Mirgel produces the vertical uni-directional turbomolecular pump 1971 Intel introduce the 4004, the world's first microprocessor. This was a 4-bit device in a 16 pin DIL package. 1974 First oil-free vacuum pump 1975 Altair computer with microprocessor introduced for home use 1975 NASA Cryo-pumps for space simulation and semiconductor manufacture 1976 April 1976, Steve Jobs and Steve Wozniak found Apple computer 1977 Mass production of valves ends in most Western European countries and the USA 1978 June 1978, the industry standard 8086 16-bit microprocessor is made. It has 29,000 transistors and a clock speed of 4.77 MHz. It was made in quantity on 4-inch silicon wafers 1986 Raytheon close the last major valve production line in the USA 1989 The 1.2 million transistor Intel 80486 is produced. The initial clock frequency is 25 MHz 1993 Intel introduce the Pentium processor. This is fabricated on 8-inch wafers. The 8-inch wafer process having been developed in April 1992
