ERICSSON TELEPHONE No. N1636 & N1637

C.B. Intercommunication Telephones
AUTO-RESET, PUSH BUTTON SELECTOR TYPE

N 1636C Type		N 1637C Type

One of the most effective means of inter-office communication where a relatively small number of lines is required, is the intercommunication telephone system, as immediate connection is established on the pressure of a button ; no operator or automatic dial being necessary. It may also be installed in large establishments as a supplementary system for the use of executives.

For many years our intercom telephones have been markedly popular by reason of their efficiency and reliability. In conformity with our progressive policy, we have redesigned these telephones on lines more in keeping with current requirements, and we are confident that they will have instant appeal, as they embody the simplicity of outline favoured for the modern office, while still retaining the proved advantages of their predecessors.

The instruments have moulded cases in fadeless black or ivory, and ivory moulded push buttons; thus, as there are no external metal parts to become tarnished, a lasting "new" appearance is ensured.

The casing is loose-hinged, and fastened by one screw, to a strong plastic baseplate carrying the internal components which are therefore accessible for maintenance when the. case is lifted off.
These components include the push button mechanisms mounted in pre-wired units of five, each unit bearing a paper strip printed with the appropriate numbers. The mechanisms are protected by a moulded panel having apertures for the buttons and designation strips, the latter being covered by convex transparent plastic windows which are bonded in and give prominence to the printed numbers.

Highly satisfactory reproduction of speech is given by the inset transmitter and electromagnetic receiver incorporated in the moulded micro-telephone, the cord from which enters the case through a rubber protector arranged to accommodate also the desk cord of the table instrument.

A moulded desk terminal block is supplied for the connection of the line wires to the table set, whilst the wires to the wall set enter through a hole in the baseplate and are connected to screw terminals. A combined instruction/directory card is supplied with each telephone.


OPERATION
To make a call, lift the micro-telephone and press the appropriate button to its full extent. If the called number is free, a buzzing tone will be heard in the receiver, indicating that the required person is being called.

A button, having been pressed, is retained in an intermediate position during the call, and is automatically released when the micro-telephone is replaced or another button is pressed; successive calls can therefore be made without replacing the micro-telephone.

Incoming calls operate a buzzer in the instrument. To reply, it is necessary only to lift the micro-telephone and speak.

POWER SUPPLY
The system is operated from a central battery, or via an eliminator when an a.c. supply is available. In either case, the best results are obtained when the source of supply is as near as possible to the centre of the system.

For a maximum line length of 2,000 feet (the approximate economic limit) a battery of nine dry or inert cells is usually adequate. Where the distance is less, the battery is proportionately smaller.

REMOTE STATIONS
If a station is remote from the main installation, an N1112A type call and reply telephone is usually supplied as a subsidiary to the nearest intercom station. The call and reply telephone can be rung from any station but can only call the one to which it is subsidiary. This arrangement effects a considerable saving in cable costs.

INSTALLATION
For a complete installation, junction boxes, cells with boxes (or an eliminator) and cable are supplied.

The type of cable recommended for a particular installation is specified in the quotation and comprises suitably insulated 9, 14 or 19, No. 23 s.w.g. copper conductors, respectively, for the 5, 10 or 15-line systems.

Dimensions (excluding h.m.t.): 6.5" x 8.75" x 4.1" (168 x 222 x 105 mm)
Total weight : 4.6 lb. (2.1 kg.) max.

Note - Orders for telephones should specify the Type No. and colour ; black or ivory.


Taken from the Ericsson catalogue, edition No. 49

Introduced around 1953 - superseded N1620 - N1627

Last revised: July 10, 2002