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Topic: Mullard at Blackburn

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Posted by Romy the Cat on 06-18-2006

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


Posted by Romy the Cat on 01-09-2008
In the end of the 40’s IBM made the Selective Sequence Electronic Calculator which contained 12,500 vacuum tubes (25L6, 6J6, 6211) that could multiply two 10-digit numbers 40 times a second. The first versions of ENIAC used 19,000 vacuum tubes. The UNIVAC had 5200 vacuum tubes and consumed 125 kilowatts of power.


Posted by guy sergeant on 09-11-2008
A nice 30 minute b/w film about the production of miniature valves by Mullard in Blackburn, England.

http://www.techtubevalves.com/about_us/film_reels.php

It would seem that some of the former employees at that site are to start producing some audio valves once again

http://www.techtubevalves.com/index.php

Posted by Romy the Cat on 05-30-2009
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Here is a very good article about the development tube types in the 1920 and the birth of my Telefunken RE-604

 http://www.goodsoundclub.com/PDF/ProliferationTubeTypes.pdf

 Then, here is very cool later but still old advertising from Telefunken, there is certainly an interesting “class” in thie ad:

The Cat

Posted by Romy the Cat on 05-16-2012
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Page 1 of 1 (5 items)