George I would like to hear anything you know about this equipment.

I may have been mistaken on the comm.

There is a 1/4" jack on the front (picture 5) labeled "General Gongs" do you know what that did?

The manual pull station I have (the only part I have Paul [Linked Image] ) is station 2-2.

The craftsmanship of these units is unbelievable, I will try to remove the plastic cover and send a better shot of the mechanism.

For those that are not familiar with the old type master box, they are the "Shed shaped fire alarm boxes on the side of buildings.

[Linked Image from stjohnsburyfire.com]

Inside was basically a telegraph system that the key was pushed by a rotating wheel with bumps corresponding to the box number.

These old style boxes are very reliable, and could get a signal back to the fire station even with parts of the telegraph loop open.

Bob Badger
Construction & Maintenance Electrician
Massachusetts