Gaumont-Kalee Type 493

British Acoustic Films Ltd (B.A.F), a maker of cinema, sound, and film equipment, was acquired by Gaumont British and later underwent several reorganisations and ownership changes.

Although this example is stamped with BAF as the maker's mark, it appears in a Gaumont-Kalee catalogue alongside their ribbon microphone.

BAF made another huge ribbon microphone called the type NZ. (Photographs 1, 2, 3 )

This microphone is unique in that it contains two condenser capsules arranged side by side, each powered by valve circuitry. The output is via a six pin socket with a screw thread.

From the 1951 Gaumont Kalee catalogue, page 121

Frequency response substantially flat ±3dB from 50 to 10,000 Hz.

About the BAF / Gaumont Kalee microphones at the Xaudia blog.

Martin Mitchell's blog post about the BAF microphones

History of BAF at Graces Guide