TELEPHONE No. 21
Supersedes Telephone No. 17.
Also known as the Post Office telephone for Granular Transmitter 'C' (GTC).
Wooden wall telephone used in CBS areas and long distance party lines.
Uses a Deckert transmitter but may be converted to a transmitter inset - Transmitter No. 3.
The GPO Stores Rate Book 1928 advises that this telephone was used on Wallboards, telephone, with fire-signal, M.F.B.
Last revised: January 03, 2016