Buzzers and Hooters
There is a difference between Bells and Bellsets. A Bell consists of a bell ringer
mechanism only and this may be an open type bell or enclosed within a case. A Bellset
consists of a bell ringer mechanism plus addition items of equipment (could be anything
from a relay to capacitors and can include switches).
The diagrams for Bell, Bellsets, Buzzers and hooters are in the N500 - N599 range. In
general prefix a Bellset number with 5. e.g. Bellset No 48 is diagram N548.