|MAGNETO, CONVERTIBLE (1000)
This instrument is for use in magneto or C.B.S. areas which will ultimately become C.B. or auto. It is arranged for rapid, simple adaptation to any of the following systems and is suitable for lines of up to 1000 ohms loop resistance.
To convert to auto (the only conversion requiring extra apparatus) it is necessary only to replace the dial dummy by a dial and disconnect the battery; circuit changes are made by modifying wire strappings at screw terminals. The same induction coil is used and no internal wiring changes are required. The hand generator may be left in position, the handle being replaced by a small cover plate.
Conversion to other than auto, excepting earth clear systems, involves only the changing of terminal strappings and disconnection of the battery and generator if required. For earth clear systems a small internal wiring change to connect the bell coils in parallel, instead of in series, is necessary.
Changes can be made easily and quickly at subscriber's premises and no subscriber need be left for long without telephone service. If necessary, when converting to auto, dials could be fitted and connected and the terminal strappings modified later, so that telephones could operate on the old system as long as possible.
The telephone apparatus mounted on the metal base can be exposed by lifting off the case after releasing four captive screws.
The handset is shaped for maximum efficiency. It has a rocking-armature inset receiver and an inset transmitter. Used in conjunction with the closed-iron-circuit type anti-side-tone induction coil, a very high quality of transmission is assured.
The generator being of rotating-magnet type has smooth crank action. Line and battery wires terminate at a moulded desk terminal block connected to the telephone by a close-braided 5 way cord.
All connecting wires and cord conductors are p.v.c. insulated.
Cells for local battery are not supplied unless ordered.
Diagrams showing the connections for the various systems are supplied with each telephone.
Taken from the Ericsson catalogue, edition No. 55
Last revised: June 08, 2020