Australian Post Office
Telephone No. 1

Magneto Wall, Commonwealth Type

This type of magneto telephone was also called the Commonwealth Ericsson. It became a standard telephone in with the formation of the Postmaster-General's Department (PMG) in 1901 but the same model had been used by all the previous colonial Post & Telegraph administrations.  Initially the model was the standard Ericsson AB 535 but later versions were made specifically for Australian conditions.  These modified versions incorporated internally mounted line fuses and improved protection against lightening strikes.  The PMG made major purchases of the AB 535 model in 1901, 1903, and 1905. Modified versions were purchased in 1907, 1909 and 1911.  Many of the AB 535 model were also used private telephone systems.

The handset and transmitter were connected in parallel rather than in series.  The line terminals on the earliest versions were in lacquered brass, but this was changed to nickel plate.  Line fuses were mounted internally.

Model AB530 had a 4-magnet generator and a ringer resistance of 300 ohms.
Model AB535 had a 4-magnet generator and a ringer resistance of 1000 ohms.
Model AB590 had a 5-magnet generator and a ringer resistance of 2000 ohms.

The No.1 was widely used in country areas and new installations of this type continued throughout the 1920's.  An instruction booklet was issued to subscribers to show them how to carry out minor maintenance such as changing batteries and repairing breaks in the telephone line.  This was necessary as some subscribers could be as far as 200 miles from the telephone exchange that was located in the town Post Office.  PMG technicians and linesmen in country areas had only horses or bicycles for transport until the 1930's.

The No.1 was reclassified as the 131MW when the PMG revised its numbering scheme in the late 1930's.  Many of these telephones were refurbished and used for new installations when other standard telephones were not available due to shortages during World War II.  There was also a cut-down version made in the PMG Workshops and re-designated as the 127MW . By 1951 the No.1 or 131MW was classified as obsolete but a few were still in service as late as 1965 when many country areas were converted to automatic working.

ATCS Article on the Commonwealth Ericsson

Circuit Diagram from Connections of Telephonic Apparatus and Circuits, PMG 1914

Schematic Diagram

When ringing out, the handset button must be depressed to stop the bell from ringing.


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Last revised June 28, 2022