Marconi-Sykes Magnetophone, Serial Number 271376, made by Marconi's Wireless Telegraphy Company Limited, probably Chelmsford, Essex, England, 1923. Very early moving coil microphone, DC energised. Uses the large flat coil as the diaphragm. Used at the BBC's early studio at Savoy Hill. This example is missing the coil.

The Marconi-Sykes magnetophone was the first custom built microphone the BBC commissioned. Introduced in May 1923, it was much more sensitive at picking up sound than previous technology and dramatically improved the audio quality of the radio broadcasts made by the BBC.

It is a moving coil type microphone housed in a magnetised cylindrical iron pot which made it extremely heavy. The aluminium coil was so fragile it needed to be supported by a backing paper, which was then supported by cotton wool pads covered with Vaseline or butter. Due to the extreme sensitivity of the microphone coil, the cotton wool was needed to dampen the movement slightly. The mic was hung from a rubber sling to reduce outside vibrations affecting the coil, inside a copper mesh cage on wheels (known as the ‘meat safe’) to reduce electromatic interference being picked up.

This model of mic was used in the famous Nightingale broadcasts on BBC radio from 1924 onwards. Cellist Beatrice Harrison played outside in her garden, with Nightingales joining in song forming a duet.

The microphone was soon replaced by even better technology, but it represents an important step in microphone design and the history of the BBC.