The STC Type 4017C
moving coil microphone
Dicky Howett writes: This is my BBC outside broadcast microphone type STC 4017C, complete and very rare with its detachable oak handle (the cable went up the centre). The mic type was first introduced by STC and the BBC in 1938. The design originated from the Western Electric type 618A (circa 1931), which used a moving coil as the transducer. These brass STC microphones (very heavy at 1.5 kg) were used by BBC Radio throughout the Second World War and can be seen (hand-held interviewing) in many BBC photographs of the period. The microphone’s overall performance was excellent, with coil resonances damped by acoustic filtering, which was incorporated in the mechanical construction. The 4017C remained in widespread BBC use up to about 1953. The letters “LO OB” are stamped below the mic on the metal stem. They referred to “LOndon OB” (outside broadcasts). The “BBC” badge pictured is an exact reproduction.
Photographs courtesy of Mr. Dicky Howett. Textbook pages courtesy of the BBC and Mr. Roger Beardsley.