An STC 4035-B microphone, Ser. No. 368, c.1950, in box marked 'SPARES FOR BIG BEN ONLY'. Modified by the BBC for broadcasting the chimes of Big Ben. It was last tested in 1983 according to a sticker on the top of the box.

The omni-directional, moving coil STC 4035 microphone replaced the STC 4017-C. It was widely used for outside broadcasts, especially sport and news. This particular microphone was modified for use on Big Ben.

When the BBC first started in 1922, the hourly chimes of Big Ben were played by an announcer on a set of chime bells in the studio. By 1924, the sound of Big Ben itself was used. In the 1950s, the STC4035 microphone was installed inside the clock tower and connected directly to Broadcasting House. The microphone’s low sensitivity allowed it to be installed right next to the bell, which was ideal as engineer’s experiments had shown that if a microphone was placed any further away it would pick up the sound of the clock mechanism and even London’s traffic.

This microphone was last tested in 1983.