TELEPHONE No. 81
Fire emergency phone for use in CB and Automatic exchanges.
The Mk 4 version consisted of a Telephone No. 232 mounted on a Bellset which in turn is mounted on a wooden box that houses batteries and a hand generator. The hand generator is locked by means of a releasable bar.
The Mark 4 was introduced in 1938.
Circuit diagram - N181.
Telephone No 81 (Mark 4)
Looking down into the unit with the lid open
Pictured below is the Telephone
Last revised: December 18, 2018