WWII TANNOY MICROPHONE

Tannoy is a registered trade mark and is a Syllabic abbreviation of Tantulum Alloy, used in a form of Electrolytic rectifiers developed by the company, which when formed in London was called in 1926 'Tulsemere Manufacturing Company.'
This product has not been made since just after WW2 and was used in Public Address systems as well as military communications.
Being extremely robust it will continue to work after much abuse, making it ideal for the Army or Navy in rough conditions.

Your comments:

• A microphone with cooling fins?! Well yes, this was a very clever device, used with a transformer, re-entrant loudspeaker, and a car battery it became a Public Address system without a valve amplifier. There was even a modicum of automatic volume control by having a lamp in the circuit, (low resistance when cold, higher when hot). The fins? well if I remember right there were several Amps flowing through the carbon granules in the microphone.
  .......... John Howell, Pinner, UK., 24th of September 2012
  
  

A0316