ERICSSON
TELEPHONE No's N1073A & N1422A
 


AUTOMATIC & C.B.
GENERAL SERVICE

n1073a.jpg (8484 bytes) n1433a.jpg (6808 bytes)
Type N1073A Type N1422A

High-grade reproduction of speech, aesthetic appeal and convenience for maintenance are features of this wall telephone-a compact, robust instrument free of awkward projections and dust-harbouring ornamentation.

Black is the standard colour, but ivory, red or green sets can also be supplied.

The telephone is fixed to the wall through bushed holes in four rubber feet attached to a die-cast back plate on which the internal apparatus is mounted.

The moulded case hooks on to the top of the back plate and is fastened by a captive screw at the bottom.  When this screw is released, the case can be lifted and swung down on a suspension, leaving the equipment exposed.

Screw terminals are provided for the external wires, which enter through a hole in the plate.  Reliable operation of the cradle-switch springs, with negligible wearing of the parts, is ensured by a highly efficient roller plunger movement.

Standard components of proven efficiency are used throughout, and provision is made in the circuit to reduce side-tone to the minimum.  The handset incorporates an inset transmitter and detachable receiver.

For automatic working a standard dial is normally fitted, but dials can be supplied with numbering or impulse ratios to suit customers' requirements.

P.V.C. covered wire is used for the connections. P.V.C. insulated, nylon braided cords can be supplied if specified.

Similar telephones, with 1, 2 or 3 push buttons, are available for operating various extension schemes.

Type No.   Telephone   Comments Dimensions   Weight lb. kg.
N1073A Auto     10 in. x 10 in. x 7 in.   6.2 (2.84)
N1073A1T Auto   Tropicalised 10 in. x 10 in. x 7 in.   6.2 (2.84)
N1073A2T Auto   Tropicalised 10 in. x 10 in. x 7 in.   6.2 (2.84)
N1422A C.B.     10 in. x 10 in. x 7 in.   5.7 (2.67)

Introduced around 1955.

Taken from the Ericsson (ETL) Telephone Catalogue No. 55.


How to convert this telephone to work on the UK plug and socket system

  1. Remove the strap between Terminals 1 and 2.
  2. Remove the strap between Terminals 10 and 11.
  3. Insert a 3.3K ohm resistor between Terminals 1 and 2.
  4. Insert a strap between Terminals 11 and 12.
  5. Red wire of the new line cord to Terminal 8.
  6. White wire of the new line cord to Terminal 1.
  7. Blue wire of the new line cord to Terminal 11.
  8. Green wire of the new line cord to Terminal 3.
  9. Connect a Rectifier Element No. 205 between Terminals 5 and 6.

 


N1073A1T and N1073A2T
Circuit Diagram N84764/4


 

Internal workings of the N1073A2T

This telephone is Tropicalised and has fine mesh covering the bell sound holes and a varnished induction coil

 
 
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Last revised: September 19, 2022

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