NATIONAL TELEPHONE COMPANY
Pattern No. B20
Comprises - Hand combination Transmitter and Receiver, Cord, Automatic Cradle-switch, Induction Coil, Lightning Arrester, 4 Magnet Generator, Bell, Battery Box and Writing Desk with Paper lip.
This is a large size instrument and the generator will ring satisfactorily through the 300 ohm bell of the instrument, and a line resistance or 25,000 ohms.
Taken from the 1903 Catalogue.
Last revised: July 03, 2020