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Alan Dower Blumlein was an electronics engineer who made a great many inventions in telecommunications, sound recording, stereo, television and radar. He received 128 patents. The field of electronics is the study and use of systems that operate by controlling the flow of electrons (or other charge carriers) in devices such as thermionic valves and semiconductors. ...
Look up engineer in Wiktionary, the free dictionary. ...
BlackBerry 7100t Telecommunication refers to the communication of information at a distance. ...
Methods and media for sound recording are varied and have undergone significant changes between the first time sound was actually recorded for later playback until now. ...
Symbol for stereo Stereophonic sound, commonly called stereo, is the reproduction of sound, using two independent audio channels, through a pair of widely separated speaker systems, in such a way as to create a pleasant and natural impression of sound heard from various directions as in natural hearing. ...
This long range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll[1]. Radar is a system that uses radio waves to detect, determine the distance of, and map, objects such...
A patent is a set of exclusive rights granted by a state to a person for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or composition of matter (substance) (known as an invention) which is new, inventive, and...
 Front cover of Blumlein biography Image File history File links Alan_Blumlein. ...
Introduction
Alan Dower Blumlein was born on June 29, 1903 in Hampstead, London. His future career seems to have been determined by the age of seven, when he presented his mother with an invoice for repairing the doorbell, signed "Alan Blumlein, Electrical Engineer". June 29 is the 180th day of the year (181st in leap years) in the Gregorian Calendar, with 185 days remaining. ...
1903 (MCMIII) was a common year starting on Thursday (see link for calendar). ...
Hampstead is a place in the London Borough of Camden and near to Hampstead Heath. ...
This article is about the British city. ...
After matriculating at Highgate School in 1921, he studied at City and Guilds College (part of Imperial College). He won a Governor's scholarship and joined the second year of the course. He graduated with a first class honours B.Sc two years later. The matriculation ceremony at Oxford Matriculation refers to the formal process of entering a university, or of becoming eligible to enter by acquiring the required prior qualifications. ...
Highgate School is a famous British private day school in Highgate, North London. ...
Imperial College London is a college of the University of London (although negotiations with regard to its withdrawal from the University are underway) and primarily focuses on science, engineering and medicine, complemented by a business school. ...
The British undergraduate degree classification system is a grading scheme used to distinguish between the achievements of undergraduate degree holders (such as those gaining bachelors degrees or undergraduate masters degrees) in the United Kingdom. ...
A Bachelor of Science (B.S., B.Sc. ...
He died on June 7, 1942, during a trial of the airborne H2S radar, when the Halifax bomber he was flying in crashed, killing everyone on board. June 7 is the 158th day of the year in the Gregorian calendar (159th in leap years), with 207 days remaining. ...
This article is about the year. ...
An early H2S picture of the Pembroke and Milford Haven area The H2S radar was used in bombers of RAF Bomber Command. ...
Halifax W1057 ZA-X of No. ...
Career and inventions
Telecommunications In 1924 Blumlein started his first job at International Western Electric, a division of Bell Labs. The company subsequently became International Standard Electric Corporation and then Standard Telephones and Cables (STC). This article lacks information on the importance of the subject matter. ...
Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ...
Standard Telephones and Cables Ltd (later STC plc) was a British telephone, telegraph, radio, telecommunications and related equipment R&D manufacturer. ...
During his time there, he measured the amplitude/frequency response of human ears, and used the results to design the first weighting networks. In telecommunication, a noise weighting is a specific amplitude-vs. ...
In 1924 he published (with Professor Edward Mallett) the first of his only two IEE papers, on high-frequency resistance measurement. This won the IEE's 'Premium' award for innovation. The following year he wrote (with Norman Kipping) a series of seven articles for Wireless World. Not to be confused with the Institute of Electrical and Electronics Engineers (IEEE, I-triple-E). ...
Wireless World was the preeminent British magazine for radio and electronics enthusiasts. ...
In 1925 and 1926, Blumlein and John Percy Johns designed an improved form of loading coil which reduced crosstalk in long-distance telephone lines. These were used until the end of the analogue telephony era. The same duo also invented an improved form of AC measurement bridge which became known as the Blumlein Bridge. These two inventions were the basis for Blumlein's first two patents. In electronics, a loading coil is a coil (inductor) that does not provide coupling to any other circuit, but is inserted in a circuit to increase its inductance. ...
In telecommunication, the term crosstalk (XT) has the following meanings: 1. ...
A Wheatstone bridge is a measuring instrument invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843. ...
His inventions while working at STC resulted in another five patents, which were not awarded until after he left the company in 1929.
Sound recording In 1929 Blumlein handed in his notice at STC and joined the Columbia Graphophone Company, where he reported directly to general manager Isaac Shoenberg. The Columbia Graphophone Company was one of the earliest gramophone companies in the United Kingdom. ...
Sir Isaac Shoenberg Sir Isaac Shoenberg (March 1, 1880 - January 25, 1963) was an electronic engineer born in Russia who was best known for his role in history of televesion. ...
His first project was to find a method of disc cutting that circumvented a Bell patent in the Western Electric moving-iron cutting head then used, and on which substantial royalties had to be paid. He invented the moving-coil disc cutting head, which not only got around the patent, it offered greatly improved sound quality. He led a small team which developed the concept into a practical cutter. The other principal team members were Herbert Holman and Henry 'Ham' Clark. Their work resulted in several patents.
Early in 1931, the Columbia Graphophone Company and the Gramophone Company merged and became EMI. New joint research laboratories were set up at Hayes and Blumlein was officially transferred there on 1st November the same year. The Gramophone Company, based in the United Kingdom, was one of the early recording companies. ...
The EMI Group is a major record label, based in Kensington in London, in the United Kingdom. ...
Hayes is a place in the London Borough of Hillingdon. ...
During the early 1930s Blumlein and Herbert Holman developed a series of moving-coil microphones, which were used in EMI recording studios and by the BBC at Alexandra Palace. The British Broadcasting Corporation (BBC) is the largest publicly-funded radio and television broadcasting corporation of the United Kingdom (see British television) and the world. ...
Alexandra Palace from the east Alexandra Palace was built on a hill in Muswell Hill in North London in 1873 as a public entertainment centre. ...
Stereo Blumlein developed his ideas on what he called 'binaural sound', now known as stereo, during this same period.
In early 1931, Blumlein and his wife were at a local cinema. The sound reproduction systems of the early 'talkies' invariably only had a single set of speakers - which could lead to the somewhat disconcerting effect of the actor being on one side of the screen whilst his voice appeared to come from the other. Blumlein declared to his wife that he had found a way to make the sound 'follow' the actor across the screen.
The genesis of these ideas is uncertain, but he explained them to Shoenberg in the late summer of 1931. His earliest notes on the subject are dated 25 September 1931, and his patent was applied for on 14 December 1931 ("Improvements in and relating to Sound-transmission, Sound-recording and Sound-reproducing systems", No. 394325).
Whereas work led by Harvey Fletcher at Bell Labs at about the same time considered sound systems using multiple channels, Blumlein always aimed at a system with just two channels. Harvey Fletcher (September 11, 1884 - July 23, 1981) was an American physicist. ...
The patent covered many ideas in stereo, some of which are used today and some not. Some 70 claims include:
- A 'shuffling' circuit, which aimed to preserve the directional effect when sound from a spaced pair of microphones was reproduced via a pair of loudspeakers instead of stereo headphones;
- The use of a coincident pair of velocity microphones with their axes at right angles to each other, which is still known as a 'Blumlein Pair';
- Recording two channels in the single groove of a record using the two groove walls at right angles to each other and 45 degrees to the vertical;
- A stereo disc-cutting head;
- Using hybrid transformers to matrix between left and right signals and sum and difference signals;
Binaural experiments began in early 1933, and the first stereo discs were cut later the same year. The Blumlein Pair is a stereo recording technique invented by Alan Blumlein for the creation of recordings that — upon replaying through headphones or loudspeakers — recreate the spatial characteristics of the recorded signal. ...
Much of the development work on this system for cinematic use did not reach completion until 1935. In a few short test films (most notably, 'Trains At Hayes Station' and, 'The Walking & Talking Film'), Blumlein's original intent of having the sound 'follow' the actor was realised fully.
Television Television was developed by many individuals and companies throughout the 1920s and 1930s. Blumlein's contributions, as a member of the EMI team, started in earnest in 1933 when his boss, Isaac Shoenberg, assigned him full-time to TV work.
His ideas included:
- Resonant flyback scanning (the use of a tuned circuit in the creation of a sawtooth deflection waveform). (British Patent No. 400976, application filed April 1932.)
- Use of constant-impedance network in power supplies to obtain voltage regulation independent of load frequency, extending down to DC (421546, filed 16 June 1933).
- Black-level clamping (422914, filed 11 July 1933 by Blumlein, Browne and Hardwick). This is an improved form of DC restoration, compared to the simple DC restorer (consisting of a capacitor, diode and resistor) which had been patented by Peter Willans three months earlier.
Personal Life Alan Dower Blumlein had two sons, Simon and David. David Blumlein founded his own school, Clifton Lodge, which is in Ealing. He has been headmaster of Clifton Lodge ever since it was created, and the school, while being very small, has been sending boys to the top public schools in the country consistently year after year.
See also An early H2S picture of the Pembroke and Milford Haven area The H2S radar was used in bombers of RAF Bomber Command. ...
External links - Dora Media Productions: authorised Blumlein biography
- Blumlein page at AlanTuring.net
- IEEE Virtual Museum
References - Alexander, Robert Charles[1] (1999). The Inventor of Stereo: The Life and Works of Alan Dower Blumlein. Focal Press. ISBN 0240516281.
- Burns, Russell W (2000). The Life and Times of A. D. Blumlein. IEE History of Technology series. ISBN 085296773X
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