The BBC-Marconi Type A is a

ribbon microphone A ribbon microphone, also known as a ribbon velocity microphone, is a type of microphone that uses a thin aluminum, duraluminum or nanofilm of electrically conductive ribbon placed between the poles of a magnet to produce a voltage by electroma ...

that was produced by the

BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...

and

Marconi Guglielmo Giovanni Maria Marconi, 1st Marquess of Marconi ( ; ; 25 April 1874 – 20 July 1937) was an Italian electrical engineer, inventor, and politician known for his creation of a practical radio wave-based wireless telegraph system. This ...

between 1934 and 1959. The microphone has been described as "iconic" and a symbol of the BBC.

History

In the early 1930s, the BBC became aware of

RCA RCA Corporation was a major American electronics company, which was founded in 1919 as the Radio Corporation of America. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westinghou ...

's model 44 ribbon microphone that was used in

Hollywood Hollywood usually refers to: * Hollywood, Los Angeles, a neighborhood in California * Hollywood, a metonym for the cinema of the United States Hollywood may also refer to: Places United States * Hollywood District (disambiguation) * Hollywood ...

. Each pair of microphone and

amplifier An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power su ...

would have cost the BBC £130 (approximately £6,500 in 2009. because of inflation)Based on a

retail price index In the United Kingdom, the Retail Prices Index or Retail Price Index (RPI) is a measure of inflation published monthly by the Office for National Statistics. It measures the change in the cost of a representative sample of retail goods and servi ...

calculatio

/ref>). As this was not within the BBC's budget, they designed their own microphone, the Type A, alongside Marconi. There were initial concerns that the new design Patent infringement, infringed the patent of the RCA microphone, but these were overcome. The Type A was produced at a cost of £9 each (approximately £475 in 2009). The original Type A microphone was designed by engineer F. W. Alexander under the guidance of H. L. Kirke's Research Department at the BBC. In 1940, the Type A was used in the broadcast of

Charles de Gaulle Charles André Joseph Marie de Gaulle (22 November 18909 November 1970) was a French general and statesman who led the Free France, Free French Forces against Nazi Germany in World War II and chaired the Provisional Government of the French Re ...

's 1940 appeals. In the early 1950s, the BBC began to design the Type A's successor. The first model was the

pressure gradient In hydrodynamics and hydrostatics, the pressure gradient (typically of air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular locat ...

PGD design. In 1953, production began on the PGS (pressure gradient single) ribbon microphone in agreement with the company

Standard Telephones and Cables Standard Telephones and Cables Ltd (later STC public limited company, plc) was a British manufacturer of telephone, telegraph, radio, telecommunications, and related equipment. During its history, STC invented and developed several groundbreakin ...

(STC). In the mid-1970s, STC's manufacturing was transferred to

Coles Electroacoustics Coles may refer to: Businesses *Coles Supermarkets, a supermarket chain in Australia *Coles Group, parent company of Coles Supermarkets, Coles Online, Coles Local, Coles Liquor and flybuys *Coles (bookstore), a bookstore chain in Canada, a divisi ...

, who continue to manufacture the PGS under the model number 4038.

Technical

Four versions of the microphone were produced – the "A", "AX", "AXB", and "AXBT". The original microphone used a thick aluminium ribbon which produced a harsh

resonance Resonance is a phenomenon that occurs when an object or system is subjected to an external force or vibration whose frequency matches a resonant frequency (or resonance frequency) of the system, defined as a frequency that generates a maximu ...

. This was soon replaced with a thinner ribbon, and was named Type AX. In 1943, the AXB model was launched, which featured balanced wiring. In 1944, the microphone was renamed the AXBT with the addition of a Ticonal magnet to increase sensitivity by 6

decibel The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whos ...

s. The AXBT weighed approximately . The microphone had a figure-of-eight polar pattern. The aluminium ribbon was less than one

micrometre The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...

thick.

Footnotes

Sources

* (

Wayback Machine The Wayback Machine is a digital archive of the World Wide Web founded by Internet Archive, an American nonprofit organization based in San Francisco, California. Launched for public access in 2001, the service allows users to go "back in ...

cached version of page) * * * * * * * * * * {{refend Ribbon microphones Products introduced in 1934 BBC history