BBC-Marconi Type A
Encyclopedia
The BBC-Marconi Type A was a ribbon microphone
that was produced by the BBC
and Marconi
between 1934 and 1959. The microphone has been described as "iconic" and a symbol of the BBC, and has become an interface metaphor
for sound recording.
's model 44 ribbon microphone that was used in Hollywood
. Each pair of microphone and amplifier
would have cost the BBC £130 (approximately £6,500 in 2009). 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 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
's 1940 appeals
.
In the early 1950s, the BBC began to design the Type A's successor. The first model was the pressure gradient PGD design. In 1953, production began on the PGS (pressure gradient single) ribbon microphone in agreement with Standard Telephones and Cables
(STC). In the mid 1970s, STC's manufacturing was transferred to Coles Electroacoustics, who continue to manufacture the PGS under the model number 4038
.
. 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
s. The AXBT weighed approximately 9.25 pounds (4.2 kg).
The microphone had a figure-of-eight polar pattern. The aluminium ribbon was less than one micrometre
thick.
Ribbon microphone
A ribbon microphone is a type of dynamic microphone that uses a thin aluminum, duraluminum or nanofilm ribbon placed between the poles of a magnet to generate voltages by electromagnetic induction...
that was produced by the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
and Marconi
Marconi
-People:*Guglielmo Marconi, Italian-born radio pioneer*David Marconi, American screenwriter*Dominic Anthony Marconi, American Roman Catholic bishop*Enrico Marconi, also known as Henryk Marconi, architect*Gloria Marconi, Italian long-distance runner...
between 1934 and 1959. The microphone has been described as "iconic" and a symbol of the BBC, and has become an interface metaphor
Interface metaphor
An Interface metaphor is a set of user interface visuals, actions and procedures that exploit specific knowledge that users already have of other domains. The purpose of the interface metaphor is to give the user instantaneous knowledge about how to interact with the user interface...
for sound recording.
History
In the early 1930s, the BBC became aware of RCARCA
RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
's model 44 ribbon microphone that was used in Hollywood
Cinema of the United States
The cinema of the United States, also known as Hollywood, has had a profound effect on cinema across the world since the early 20th century. Its history is sometimes separated into four main periods: the silent film era, classical Hollywood cinema, New Hollywood, and the contemporary period...
. Each pair of microphone and amplifier
Audio amplifier
An audio amplifier is an electronic amplifier that amplifies low-power audio signals to a level suitable for driving loudspeakers and is the final stage in a typical audio playback chain.The preceding stages in such a chain are low power audio amplifiers which perform tasks like pre-amplification,...
would have cost the BBC £130 (approximately £6,500 in 2009). 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 infringed the patent
Patent infringement
Patent infringement is the commission of a prohibited act with respect to a patented invention without permission from the patent holder. Permission may typically be granted in the form of a license. The definition of patent infringement may vary by jurisdiction, but it typically includes using or...
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 de Gaulle
Charles André Joseph Marie de Gaulle was a French general and statesman who led the Free French Forces during World War II. He later founded the French Fifth Republic in 1958 and served as its first President from 1959 to 1969....
's 1940 appeals
Appeal of June 18
The Appeal of 18 June was a famous speech by Charles de Gaulle, the leader of the Free French Forces, in 1940. The appeal is often considered to be the origin of the French Resistance to the German occupation during World War II. De Gaulle spoke to the French people from London after the fall of...
.
In the early 1950s, the BBC began to design the Type A's successor. The first model was the pressure gradient PGD design. In 1953, production began on the PGS (pressure gradient single) ribbon microphone in agreement with Standard Telephones and Cables
Standard Telephones and Cables
Standard Telephones and Cables Ltd was a British telephone, telegraph, radio, telecommunications and related equipment R&D manufacturer. During its history STC invented and developed several groundbreaking new technologies including PCM and optical fibres.The company began life in London as...
(STC). In the mid 1970s, STC's manufacturing was transferred to Coles Electroacoustics, who continue to manufacture the PGS under the model number 4038
Coles 4038
The Coles 4038 is a ribbon microphone produced by Coles Electroacoustics. The microphone was designed and patented by the BBC in the 1950s and was originally known as the STC 4038. The sound of the microphone has been described as "British" with a "BBC politeness", and its appearance has been...
.
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 resonanceResonance
In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
. This was soon replaced with a thinner ribbon, and was named Type AX. In 1943, the AXB model was launched, which featured balanced wiring
Balanced audio
Balanced audio is a method of interconnecting audio equipment using impedance-balanced lines. This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external noise.Balanced connections use...
. In 1944, the microphone was renamed the AXBT with the addition of a Ticonal
Alnico
Alnico is an acronym referring to iron alloys which in addition to iron are composed primarily of aluminium , nickel and cobalt , hence al-ni-co, with the addition of copper, and sometimes titanium. Alnico alloys are ferromagnetic, with a high coercivity and are used to make permanent magnets...
magnet to increase sensitivity by 6 decibel
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
s. The AXBT weighed approximately 9.25 pounds (4.2 kg).
The microphone had a figure-of-eight polar pattern. The aluminium ribbon was less than one micrometre
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
thick.