The Siren Board

I had the privilege of working on a Model 3 siren. However, I do not know much, or really anything about these. Anyone know what years these were manufactured? This was a single phase unit that was not working. Glad to say it is back in service for fire calls now.

What is interesting is that model 3's is that they have the same chopper/stator that 2001's use, that's why they are usually a tad higher pitched than the 5 and 7. The housing is also a little bit different too, it's a little smaller, and the top cone and louver are the same diameter. Glad to hear it got a new lease on life!

to nitpick, the reason 2001s are higher pitched is because the DC motor isn't inherently speed limited like an induction motor is. 2-pole induction motors are limited to ~ 3500-3550 rpm with no load, and typically sirens would run them at 3450. The 2001's motor is powerful enough to spin the chopper up to 3950 rpm (in the 2001-130.)

Good info to have. Any idea on a manufacture date of these units? I do have a recording of it that I may upload sometime.

At least 50 years ago, that's when my town said they bought theirs. It has since been replaced by a T-121 and is currently restored and on display in my basement.