M-OV (Marconi-Osram Valve Company) was a British manufacturer of thermionic valves (vacuum tubes). It was a subsidiary of the (British) General Electric Company Ltd. It was named after the Marconi Company and Osram, which were two major manufacturers of the tube.

History

The company was founded in 1919, when the valve making interests of GEC (Osram) and the

Marconi Company The Marconi Company was a British telecommunications and engineering company founded by Italian inventor Guglielmo Marconi in 1897 which was a pioneer of wireless long distance communication and mass media broadcasting, eventually becoming on ...

were combined. In 1929, Marconi sold its interest in the company to the

Gramophone Company The Gramophone Company Limited was a British phonograph manufacturer and record label, founded in April 1898 by Emil Berliner. It was one of the earliest record labels. The company purchased the His Master's Voice painting and trademark righ ...

, a predecessor of

EMI EMI Group Limited (formerly EMI Group plc until 2007; originally an initialism for Electric and Musical Industries, also referred to as EMI Records or simply EMI) was a British transnational conglomerate founded in March 1931 in London. At t ...

. In 1939, M-OV acquired two disused cotton mills at Shaw, Oldham where it established a shadow factory to produce valves and cathode ray tubes. The two mills named Cape and Duke, were bought from the

Lancashire Cotton Corporation The Lancashire Cotton Corporation was a company set up by the Bank of England in 1929, to rescue the Lancashire spinning industry by means of horizontal rationalisation. In merged 105 companies, ending up in 1950 with 53 operating mills. It was ...

for £7,000. Cape mill was used as the main production facility at Shaw, with the adjacent Duke mill remaining mostly unused. Shaw produced a vast array of valves for the war effort, some of which are listed below. * VT104 and VT105 for the T1154 transmitter. * VR99, VR100, VR101 and VR103 for the R1155 receiver. * TT11 for the TR1143 fighter set. * VT90 micropup used in airborne radar. EMI sold its share of M-OV to GEC in 1956. The company continued to manufacture valves at the Brook Green Works, Hammersmith, London, until 1988. M-OV branded

new old stock New old stock (NOS), or old stock for short, refers to aged stock of merchandise that was never sold to a customer and is still new in original packaging. Such merchandise may not be manufactured anymore, and the new old stock may represent the on ...

valves, continue to be highly prized by enthusiasts of the valve sound. Notable products of the company included

cathode ray tube A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms on an oscilloscope, a ...

s for television, starting in the 1930s. The company also introduced the KT66 "kinkless tetrode" (beam power tetrode). In 1922 the company brought out valves using thoriated tungsten filaments, which needed less battery power to operate than former types. During World War II the company developed the CV122 valve used in the

proximity fuse A Proximity Fuse (also VT fuse or "variable time fuze") is a fuse that detonates an explosive device automatically when it approaches within a certain distance of its target. Proximity fuses are designed for elusive military targets such as air ...

Bibliography

* Barry Vyse & George Robert Jessop, ''The Saga of Marconi-Osram Valve: A History of Valve-making at One of the World's Foremost Enterprises'', Vyse Ltd, 2000

External links

* http://www.gracesguide.co.uk/Marconi-Osram_Valve_Co Electronics companies of the United Kingdom General Electric Company Electronics industry in London Defunct technology companies of the United Kingdom Electronics companies established in 1919 1919 establishments in England {{electronics-stub