View source for Mullard

{{short description|British manufacturer of electronic components}}
{{For|the crossbred duck popular as a food|Mulard}}{{For|the surname|Mullard (surname)}}
{{EngvarB|date=April 2018}}
{{Use dmy dates|date=April 2018}}
{{Infobox company
| name = Mullard
| logo = Mullard Shield Logo.svg
| type = 
| fate = 
| predecessor = <!-- or: | predecessors = -->
| successor = <!-- or: | successors = -->
| founded = 1920 <!-- if known: {{Start date and age|YYYY|MM|DD}} in [[city]], country -->
| founder = [[Stanley R. Mullard]] <!-- or: | founders = -->
| defunct = <!-- {{End date|YYYY|MM|DD}} -->
| hq_location_city = 
| hq_location_country = United Kingdom
| industry = [[Electronics]]
| products = {{Unbulleted list|[[Electronic Components]]|[[Transistors]]|[[Vacuum Tubes]]}}
| num_employees = 
| num_employees_year = <!-- Year of num_employees data (if known) -->
| parent = [[Philips]]
| website = <!-- {{URL|example.com}} -->
}}
[[File:TDD4.JPG|thumb|upright|A Mullard TDD4 valve. 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.<ref>{{cite web |url=http://www.r-type.org/static/makemull.htm |title=Mullard |work=The National Valve Museum |accessdate=14 January 2017}}</ref>]]
[[File:Mullard el34.jpg|upright|thumb|A Mullard [[EL34]] power pentode]]
[[File:Mullard el84 vacuum tube.jpg|thumb|An [[EL84]] valve made in Russia in the 21st century]]

'''Mullard Limited''' was a British manufacturer of [[electronics|electronic]] components. The '''Mullard Radio Valve Co. Ltd.''' of [[Southfields]], London, was founded in 1920 by Captain [[Stanley R. Mullard]], who had previously designed [[thermionic valves]] for the Admiralty before becoming managing director of the Z Electric Lamp Co.<ref>{{cite web |url=https://www.gracesguide.co.uk/Stanley_Robert_Mullard |title=Stanley Robert Mullard (1883-1979)}}</ref> 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]].

==Start-up==
In 1921, the directors were Sir Ralph Ashton (chairman), [[Basil Binyon]] of the Radio Communication Co, [[Cyril Frank Elwell|C.F. Elwell]] and S.R. Mullard (managing director).<ref>{{cite web |title=The Radio Review Vol.2 1921 |url=https://worldradiohistory.com/hd2/IDX-Site-Early-Radio/Archive-Wireless-World-IDX/20s/Radio-Review-1921-02-OCR-Page-0045.pdf |access-date=26 July 2021}}</ref>

==Partnership with Philips==
In 1923, to meet the technical demands of the newly formed [[BBC]], Mullard formed a partnership with the Dutch manufacturer [[Philips]].  The [[vacuum tube|valves]] (vacuum tubes) 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 the end of New Road, [[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 Philips opened a plant in [[Blackburn]], Lancashire, and during the Second World War some operations were moved there from Mitcham; by the end of the war, nearly 3,000 were employed. Tungsten and molybdenum wire were produced on-site from 1954, and a glass factory was built in 1955. In 1962 over 6,200 were employed and Mullard described the Blackburn works as "the largest valve manufacturing plant in Europe".<ref>{{YouTube|id=GDvF89Bh27Y|title=The Blackburn Story – Mullard film, 1960s}}</ref>

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, Lancashire|Simonstone]], both in Lancashire. The latter closed in 2004. There was also a sister factory at Belmont in [[Durham, England|Durham]] (closed in June 2005).<ref name="Grimley_2017">{{cite web |title=Mullard & CES - Mullard & Combined Electronic Services (CES) |author-first=Robert |author-last=Grimley |date=2016 |orig-year=2011 |work=Early Philips Colour TV |url=http://www.philipstv.org.uk:80/blog/early-philips-colour-tv/mullard-combined-electronic-services-ces/ |access-date=2017-01-14 |url-status=dead |archive-url=https://web.archive.org/web/20171027082741/http://www.philipstv.org.uk/blog/early-philips-colour-tv/mullard-combined-electronic-services-ces/ |archive-date=27 October 2017 }}</ref><ref>{{cite news |url=https://www.theguardian.com/business/2005/mar/02/17 |title=Union says LG Philips is to close Durham factory |first=Mark |last=Milner |date=2 March 2005 |newspaper=The Guardian |accessdate=14 January 2017}}</ref><ref>{{cite news |url=http://www.thejournal.co.uk/news/north-east-news/lg-philips-closure-marks-end-4611959 |title=LG Philips closure marks end of an era |date=23 July 2005 |newspaper=[[The Journal (Newcastle upon Tyne newspaper)|The Journal]] |accessdate=14 January 2017}}</ref><ref>{{cite web |url=http://www.pepnet.org.uk/RWoodcock/And%20then%20there%20were%20none.pdf |title=And Then There Were None
 |first=Ray |last=Woodcock |date=January 2006 |work=Philips Electronic Pensioners |accessdate=14 January 2017}}</ref> Other factories included those at [[Fleetwood]] (closed in 1979) and [[Lytham St. Annes]] (closed in 1972). A feeder factory at [[Haydock]] closed in 1981. A small factory in Hove closed in the early 1970s.

==Teletext==
{{main|SAA5050}}
In the early 1980s, Mullard manufactured the [[SAA5050]], one of the first [[teletext]] character generator modules made in the UK.<ref>{{Cite web|date=July 1982|title=SAA5050 Series Datasheet|url=https://vd-view.azurewebsites.net/Documents/SAA5050.pdf|access-date=16 June 2021|publisher=Mullard}}</ref>

==Semiconductors==
[[File:Early Mullard small signal transistor packages.jpg|thumb|Mullard transistors of the 1960s, showing the variety of SO-2 packages used:
{{ubl|OC200, silicon PNP transistor in an aluminium can.
|Germanium OC45 in a black-painted glass package.
|OC45 in a clear glass and blue putty package, with rubber sleeve}}]]
Mullard owned [[semiconductor]] factories in [[Southampton]] and [[Hazel Grove]], Stockport, Cheshire.

Southampton (Millbrook Trading Estate) was a purpose-built plant, opened in 1957 for the manufacture of [[semiconductor]]s. Production of germanium alloy [[transistor]]s was transferred from Mitcham. 
At the same time the plant started the research, development and production of electro optical devices. Fabrication of planar devices on a mass production basis did not begin until 1966, when germanium sales were decreasing. 1967 saw the start of the development and production of [[integrated circuit]]s. The plant was planned to be the biggest semiconductor facility in Europe, employing 3,000 people including 200 scientists and engineers.

In 1962 Associated Semiconductor Manufacturers (ASM) Ltd was formed by Mullard and [[General Electric Company|GEC]] to combine the semiconductor development and production facilities of the two companies; Mullard owned two-thirds of the company and included the Southampton plant; GEC contributed their small factory in School Street, Hazel Grove, producing [[thyristor]]s, [[rectifier]]s and power [[diode]]s. GEC pulled out of ASM Ltd in 1969.
In 1972 production was moved to a newly constructed factory nearby on Bramhall Moor Lane.

Both sites were later owned by [[NXP Semiconductors]] (formerly [[Philips Semiconductors]]). The Southampton site is now closed. Hazel Grove, Stockport specialises in [[power semiconductor device]]s and is now [[Nexperia|Nexperia Manchester]].

The first [[transistor]]s produced by Mullard were the OC50 and OC51 point-contact types in 1952, which were not widely used. In 1953 Mullard moved to junction transistors, beginning with the plastic-cased OC10 series.  These were followed by the glass-encapsulated OC43...47,<ref>Note: Mullard's OC43...47s were germanium-PNP, while [[Clevite|Clevite-Intermetall]]'s OC43...47s, sold at the same time, were silicon-PNP</ref> OC70/71, (released in 1957) and OC80 series (the output devices were metal encapsulated to facilitate heatsinking), which were produced in large numbers and copied by other companies, such as [[Valvo]] (another Philips subsidiary) and [[Siemens AG|Siemens]] in Germany, and [[Amperex]] (another Philips subsidiary) in the USA. RF transistors were the OC170 and OC171. All these were germanium PNP transistors. Mullard's first silicon transistors were the OC201 to OC207, PNP alloy types using the standard SO-2 metal-over-glass construction such as the OC200 shown. From about 1960 Mullard switched to using the BC prefix for silicon, and AC for germanium, eliminating the confusion of part numbers. in the mid-1960s the first plastic packages were introduced. In 1964 the company produced a prototype electronic desktop [[calculator]] as a technology demonstrator for its transistors and [[cold cathode]] indicator tubes.

==Space science and astronomy==
In 1957 Philips-Mullard helped to set up the [[Mullard Radio Astronomy Observatory]] (MRAO) at the [[University of Cambridge]]. In 1966 the [[Mullard Space Science Laboratory]] (MSSL) was opened near [[Dorking]], Surrey as part of [[University College London]]. The [[Royal Society]] [[Mullard Award]] for "those who have an outstanding academic record in any area of natural science, engineering or technology and to individuals or teams whose work has the potential to make a contribution to national prosperity", previously for young researchers<ref>{{cite web |url=http://www.royalsoc.ac.uk/funding.asp?id=4870 |title=Mullard Award|year=2006|work=Royal Society |archiveurl=https://web.archive.org/web/20061014220617/http://www.royalsoc.ac.uk/funding.asp?id=4870 |archive-date=14 October 2006}}</ref> but {{As of|2025|lc=y}} with no restrictions on career stage, has been awarded annually from 1967.<ref>{{cite web | title=Royal Society Mullard Award | website=Royal Society |year=2025| url=https://royalsociety.org/medals-and-prizes/mullard-award/}}</ref>

==Mullard brand name==
Philips continued to use the brand name "Mullard" in the UK until 1988. [[Mullard Research Laboratories]] in [[Redhill, Surrey|Redhill]], Surrey then became Philips Research Laboratories. As of 2007, the Mullard brand was used by [[Sovtek]] for valves<ref>{{cite web | title=New Sensor Mullard a Sovtek?| website=18Watt.com| date=5 October 2007 | url=https://www.18watt.com/viewtopic.php?t=17891}}</ref> sold as [[ECC83]], [[EL34]] (European type numbers used by Mullard and many others), etc.

==Z Electric Lamp Company==
The Z Electric Lamp Co. continued business into the 1970s operating from premises in [[Thornton Heath]], southern Greater London, manufacturing lamps of specialised design. However, it closed due to the recession in the mid-1970s.

==50th Anniversary in 1970==
To mark the 50th anniversary of the founding of the company, Mullard management decided to have a rose named after the company. Mullard's quest was simple, they wanted a world-beater, nothing less, so they contacted the renowned grower Sam McGredy IV in Northern Ireland.<ref>{{cite web |url=https://www.helpmefind.com/rose/pl.php?n=11116&tab=7&qn=1&qc=b |title=Mullard Jubilee Rose}}</ref> The naming fee of £10,000/$24,000 was a lot of money in 1970 and established a record fee for a new rose: [[Rosa 'Electron'|Mullard Jubilee "Electron"]]. To mark the occasion every employee received a "Mullard Jubilee" rose bush.

== See also ==
* [[Mullard–Philips tube designation]]
* [[MEL Equipment]]

==References==
{{reflist}}

== External links ==
{{Commons category|Mullard}}
*{{YouTube|id=GDvF89Bh27Y|title=The Blackburn Story – Mullard film, 1960s}}
*[http://www.wylie.org.uk/technology/semics/Mullard/Mullard.htm Mullard Semiconductors by Andrew Wylie]
*[https://mullard.org/blogs/news Some Mullard History on personal blog]
*[http://blog.thetubestore.com/history-of-mullard-tubes/ History of Mullard Tubes]
*[https://web.archive.org/web/20180320142215/http://www.effectrode.com/signal-tubes/speed-efficiency-perfection-aims-built-mammoth-factory-16-years/ Mullard Valve Works in Blackburn]

[[Category:Defunct technology companies of the United Kingdom]]
[[Category:Vacuum tubes]]
[[Category:Guitar amplification tubes]]
[[Category:Electronics industry in London]]
[[Category:Electronics companies of the United Kingdom]]
[[Category:Manufacturing companies based in London]]
[[Category:Electronics companies established in 1920]]
[[Category:History of the London Borough of Hammersmith and Fulham]]
[[Category:History of the London Borough of Wandsworth]]
[[Category:1920 establishments in England]]