TELEPHONE No. 17
Superseded by Telephone No. 21.
Also known as the Post Office telephone for Granular Transmitter 'A' (GTA).
Wooden wall telephone with Deckert transmitter.
This model can have an additional receiver fitted, as shown in the picture.
Similar in construction to the Telephone No. 21, this phone has different gravity switch contact arrangements.
Last revised: January 03, 2016