This instrument, used with an ordinary magneto extension telephone, enables both stations to share one exchange line and to communicate with each other, a typical application being two premises some distance apart but under common ownership, e.g., an office and warehouse.
The instrument has three push buttons for the following switching operations:
Calls from the exchange or the extension are visually indicated on the push-button-restored indicator in the front
of the instrument and are audibly indicated by one or other of the two bells provided, one of these being in the instrument and the other external. The latter is an all-metal bell, suitable for wall mounting.
The indicator operates when the extension rings off at the conclusion of exchange-to-extension conversations, which can be made secret or non-secret as desired.
If the intermediate telephone is engaged, visual and audible indication of an incoming call is not prevented.
The operation of any push button will release any other operated button.
A small battery is required for speech current for extension-to-intermediate conversations. This is supplied only when ordered.
The telephone resembles the standard general service magneto instrument in design. High-quality components are used, and the internal connecting wires are insulated with p.v.c. The external wires terminate on screw connections in a moulded desk terminal block.
P.V.C. insulated, nylon braided handset and desk cords are supplied unless otherwise specified.
Black is the standard colour, but ivory, red or green telephones also are available.
Taken from the Ericsson catalogue, edition No. 55
Last revised: October 04, 2019