|C.B., CORD, PRIVATE BRANCH EXCHANGES
These boards are fully tropical and are designed for conditions where there is a high proportion of calls to or from the public automatic or C.B. exchange.
Both are floor pattern boards, but type N204 should also be fastened to a wall, access to the interior being obtained by swinging open the hinged front. Type N325 has a removable rear door.
The hardwood case is matt polished and plug shelves are covered with black "Warerite" Wiring throughout is p.v.c. insulated.
For auto. working, a dial is fitted on the right of the front panel.
Plug-restored, totally enclosed disc indicators are used for the exchange lines. The "extension" line and the supervisory indicators are self-restoring disc type. The latter are in the keyboard on N325, and at the top of the front panel on N204.
Double positive supervision is given on local calls and single positive supervision on exchange calls.
Cord circuit relays and battery feed retards are B.P.O. type "3000".
Current for exchange calls is obtained from the public exchange.
"Dial and hold" and "through call" keys are provided for the exchange lines, and there is a "ring back" key in each cord circuit.
Cord testing and night extension facilities are incorporated, also a calling buzzer and cut-off switch.
The operator's handset has a plug and jack connection. A head and breast set can be supplied if preferred.
P.V.C.-insulated, nylon braided cords can be provided if specified.
Orders for these boards should state Type No. and the numbers of circuits to be equipped. The stock equipments are listed below. Weights given are for the full equipment.
Operating Voltage : 24 volts (nominal).
Busy Hour Current Drain for Fully Equipped Board: N204, 1.0A; N325, 2.0A.
Capacity and Wiring Equipment
Taken from the Ericsson catalogue, edition No. 55
Last revised: October 12, 2019