BELL No. 57

Trembler bell for preliminary signal and special cases in Post Office buildings.

Bell No. 57A - Twin 50 ohm coils.
Bell No. 57B - Twin 250 ohm coils.

Uses 7inch diameter wire gong (Bell-gong No. 22).

Bell No. 57B is pictured below.

Early variant - wooden cased Later variant - plastic cased (does not include the wooden plate)


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Last revised: April 02, 2020