 right|200px right|thumb|200px||mullard valve tdd4. the gold spray coating served no purpose other than to hide the blackened interior as mullard valves were still manufactured using the azide process, long abandoned by other makers.http://www.r-type.org/static/makemull.htm right|thumb|200px|famous mullard el34 power pentode thumb|200px|right|current russian production mullard el84 vacuum tube. mullard limited was a british manufacturer of electronic components. the mullard radio valve co. ltd. of southfields, london, was founded in 1920 by captain stanley r. mullard, who had previously designed valves for the admiralty before becoming managing director of the z electric lamp co. the company soon moved to hammersmith, london and then in 1923 to balham, london. the head office in later years was mullard house at 1-19 torrington place, bloomsbury, now part of university college london. ==partnership with philips== in 1923, in order to meet the technical demands of the newly formed bbc, mullard formed a partnership with the dutch manufacturer philips. the valves (us vacuum tube) produced in this period were named with the prefix pm, for philips-mullard, beginning with the pm3 and pm4 in 1926. mullard finally sold all its shares to philips in 1927. in 1928 the company introduced the first pentode valve to the british market. ==factories== ===mitcham=== mullard opened a new manufacturing plant at mitcham, surrey in 1929. a second building was added in 1936. both buildings had a very distinctive flat roof construction and were very similar to those at philips' headquarters in eindhoven, netherlands. co-sited with the mullard buildings was the manufacturing complex for philips radios. mitcham was also home to the mullard application laboratory. ===blackburn=== in the late 1930s mullard opened a new plant in blackburn, lancashire. by 1949 mullard had produced a number of television sets, such as the mts-521 and mts-684. in 1951 mullard was producing the lsd series of photographic flash tubes. ===others=== mullard had factories in southport and simonstone, near padiham both in lancashire. the latter closed in 2004. there was also a sister factory in durham. other factories included those at fleetwood (closed in 1979) and lytham st. annes (closed in 1972). a feeder factory at haydock closed in 1981. ==teletext== in the early 1980s, mullard manufactured the saa5050, some of the earliest teletext decoding modules made in the uk. ==semiconductors== mullard owned semiconductor factories in southampton and stockport. both sites were owned by nxp semiconductors (formerly [[
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