BELL No. 56

A DC bell (trembler) with a 2.5 inch gong (Gong-Bell No. 2).

Operating voltages and resistances:-
Bell No. 56A - (2 x 50 ohm coils) - 2-5 or 5-10 volts DC
Bell No. 56B - (2 x 250 ohm coils)
Bell No. 56C - (2 x 1000 ohm coils) - 10-25 or 25-60 volts DC
Bell No. 56D - (2 x 50 ohm coils) - 2-5 or 5-10 volts DC - includes Bobbin Resistance 2k ohms.
Bell No. 56E - (2 x 250 ohm coils) - with permanently wired FR Interference suppression and Resistor Carbon 2.2k ohms.

Introduced in the early 1920's.

For internal use only.

Coloured black these bells were universally used throughout by the GPO, Post Office and BT, plus many private companies.

Early versions, the Marks 1, 2 & 3, have a wooden base (see picture below) and metal cover but most found today will be made out of plastic.

Superseded the Bell No. 13.

Circuit Diagram - N656.

Drawing - 62797 (Mark 3 & 4).

Drawing - 62979 (Mark 5).

Specification - S541.

How to adjust the Bell No. 56

Bell No. 56C with a wooden base
(Picture dated 1932)

Bell No. 56C with a plastic base

Front view

Rear view
 

Last revised: November 06, 2023