BBC-Marconi Type A microphone

In the early 1930s, the BBC became aware of RCA'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. because of inflation)). 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. 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. 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". In 1944, the microphone was renamed the AXBT with the addition of a Ticonal magnet to increase sensitivity by 6 decibels. The AXBT weighed approximately . The microphone had a figure-of-eight polar pattern. The aluminium ribbon was less than one micrometre thick. == Footnotes ==