Australian Post Office
Telephone No. 41
Closed Circuit Buzzer

Closed Circuit Buzzer (Phonopore Telephone)

Comprises Howler, Condenser, Closed Circuit Buzzer and handset.

A Phonopore-style telephone made by the Victorian Workshops at some time before 1914.  It was a composite of spare parts, and the example shown uses an Ericsson handset and switchhook, and an Ericsson earpiece to produce a ring signal through the trumpet at the front.  A Collier-Marr "howler" (a modified receiver) was usually used on Phonopores, but Ericssons produced their own Phonopore equivalent phone using an earpiece as a howler.  The Workshops apparently followed this practice.

The phone was designed to provide voice communication over telegraph lines without interfering with the Morse signal.  This idea was quickly dropped by the APO in favour of dedicated phone lines.  The type of phone was kept in use by the various Railways administrations using Phonopores mostly supplied by the Sterling Telephone & Electric Co.

The telephone to the right is extremely rare, only a few examples being known in Victoria, Australia.

Taken from Bob's Old Phones

Click for an explanation and history of the Phonopore

Diagrams

An alternate version using more of the original Phonopore / Kellogg parts is shown below.
 

Circuit diagram from "Connections of Telephonic Apparatus and Circuits", PMG, 1914

Last revised June 01, 2025

FM2