Demonstration Set No. 6

Picture dated 1953

The Telephone Demonstration Set was supplied to schools, Civil Defence organisations and other bodies for teaching the use of the telephone.  There are only two telephones to the set and the conditions of normal telephone exchange working cannot be reproduced, but the functions of the telephone can be demonstrated and the pupils encouraged to become familiar with its use.  For simplicity, the magneto bell has been omitted from the telephone and a small lamp has been fitted in the case of the telephone to act as a calling device and to indicate ringing.  Where a dial is fitted, it has no electrical function but is supplied so that the use of the dial may be practised.  A dial appropriate to the local exchange area is supplied.

This combination demonstration set consists of a Demonstration Set No. 6A and a No. 6B, which are connected together by a 4-wire cable; Diagram LD 140 refers.

The No. 6A consists of a “Telephone No. 196LB” modified, connected to a “Baseboard No. 31” by a “Cord, Inst. No. 4/5713”.  The No. 6B set is similar but has a “Baseboard No. 30”.

A Battery Dry No. 9 (Eveready No. 126) is also supplied.

The modified 'Telephones No. 196 LB' has a half-inch hole in the front of the case with a miniature screw-type lamp holder, held in place by a rubber grommet.  In automatic exchange areas, either one (or both) of the telephones may be fitted with a dial of the director or non-director pattern, as appropriate.  The Combination Demonstration Set is supplied complete with lamps, a battery and 25 yards of four wire, and in addition, a booklet and a gramophone record.  The booklet (PH 906) is entitled “The Story of the Telephone” and the gramophone record describes the procedure and gives examples of the tones heard when making a call by automatic telephone.

Models produced:-
Demonstration Set No. 6A - no dial
Demonstration Set No. 6AF
Demonstration Set No. 6AL
Demonstration Set No. 6B - no dial
Demonstration Set No. 6BF
Demonstration Set No. 6BL

Diagrams - LD139 & LD140 (dated 1950).

Additional Information
Demonstration sets were produced by the GPO repair factories.  Check the base plate for the factory code and year of manufacture.  The phones were always old telephones that had been refurbished.  When a dial was fitted, the telephone number had an L (for letters) or FA (figures only) appended e.g. Demonstration Set No. 6AL.

They were simple to use and maintain.  If a bell was used then that would have involved a bellset and a ringer for each telephone, which would have put the price up considerably and also made connections extremely complicated for the lay person.

Click here for the circuit diagram

General information on 200 type telephones

Collectors Information - what to look for

How to restore Bakelite

How to dismantle a 200 type telephone

Additional Pictures

Close up of front showing the 6 volt lamp to the bottom right
General view
Base plate showing GPO factory code FBR and dated 1962
Interior view
Paster diagram inside base
Terminal plate made of wood with Paster diagram
Thanks to Peter for the pictures


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Last revised: December 05, 2022