Wooden cased telephone used a a demonstration telephone.  Normally used in pairs and sometimes called a "school set".

Each set had it's own serial number and instructions for use on the front flap.

The wiring is heavy gauge single core and covered in a 1930ís plastic type material.  All components are identified by engraved labels.

A dial is fitted and for demonstration purposes, when used, flashes the small lamp, which is situated to the right of the dial.

The units are powered by two batteries (not shown) and connected together by 4 wires.  A wiring diagram would normally be provided on the inside of the cover.

The picture to the right shows a set that has the trumpet missing from the transmitter.

Renamed as the Demonstration Set No. 1.

Circuit diagram - N322.

Additional Pictures
Courtesy of Karen of Abdy Antiques

Telephone closed
Typical marking to be found on base of case
The Telephone opened for use
Receiver removed from switchook rest to expose Induction Coil and capacitor.
Batteries would be retained by metal strap to the right.  Note the lamp to the right of the dial.
Close up of internal components
Close up of Induction coil
Close up of Transmitter
Close up of heavy gauge wiring
Instructions for using the set (fitted in glass frame on flap)


General information on 200 type telephones

Collectors Information - what to look for

How to restore Bakelite

How to dismantle a 200 type telephone

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Last revised: November 20, 2021