BELLSET No. 41

Wooden cased Bellset for use with with Telephone No. 310 on shared service separate metering lines.  Introduced circa 1946.

The Bellset No. 41 was used on Party Lines to stop bell tinkle on one of the users, when the other user dialled out.  The unit incorporated a full wave rectifier bridge and relay, in a manner that the bell was connected once a burst of ringing current was received.  As the relay was slugged (to be slow to operate), it did not respond the the spikes caused by dialling.

In 1947 the Thermistor was invented.  This was a miniature device that effectively made the Bellset No. 41A redundant, because the Thermistor could be incorporated into any size of phone.  The Thermistor was used to stop bell tinkle.

This Bellset CANNOT be used in place of a Bellset No. 1 or Bellset No. 25, because the Bellset No. 41 has no induction coil.  It can, however, be used as a basic extension bell.

Bellset includes (1956):-
1 x Bell, No. 1A, unmounted.
1 x Rectifier-element No. 1/12A.
1 x Rectifier-element No. 4/6A.
1 x Bell-gongs No. 2, oxidized.
1 x Bell-gongs No. 2A, oxidized.
1 x Relay No. 8552.
2 x Brackets, Mounting, BH
1 x Capacitor, M.C., No. 101.
1 x Clip No. 39.

Circuit diagram - N541.
Drawing No. - 63085.

Adjustment of Magneto bells

Click here for the difference between a Bell and a Bellset

How to wire a Bellset No. 41 as an extension bell

1. Remove links 8 - 9 and 6 - 7.
2. Connect a 3.3K resistor between terminals 7 and 8.
3. Connect white of the line cord to terminal 7.
4. Connect Blue of the line cord to terminal 9.
5. Insulate the red and green wires of the line cord as these are not used.

Last revised: August 25, 2022