Interesting. It kind of reminds me of how Federal Signal put numbers on sirens or control boxes to signify the year it was made. I have a question about why the 105 was changed. Was it because the dampers had a lot of problems or was it something about the design of the siren?
There's one supposedly in south central Illinois. It's on the Illinois State Siren Map. I'll find out the exact town for you guys tomorrow, or if someone takes a look before I get to it that would be great as well.
ACA wanted to keep the Screamer sirens simple for the sake of building costs - plus you already had the Banshee 110 with a damper so it was redundant to do the same thing with one of the Screamers. As for the siren in Keyesport, it was a Screamer S-2 as seen in this thread: https://airraidsirens.com/forums/viewto ... 9&start=45
No - the internal cooling fan has no space to draw in air which is crucial for sound production. It would not be any noisier than a typical motor with a cooling fan.
The damper is located within the intake pipe just beneath the actual siren chopper - it was operated with a solenoid which was housed along the intake pipe. This solenoid was connected to the same wire leads as the siren motor. These converged through an electrical box which finally lead to the siren control box.