The Siren Board

I have one question that would change my mindset about the 2001's. Here is the question. How do they work. Do they use the classic chopper and blower technique or are they all electronic?

Chopper. I couldn't tell you what port, I'll try to find out though. I'd have to guess twelve ports though.
I don't think they use blowers.

12 port rotor, the same exact design that the Model 3 used. You could look at the 2001 as a rotating dc-motor Model 3 the same way a Thunderbolt is basically a rotating Model 2. And technically most mechanical sirens have a blower, since the rotor is not much more than an axial blower wheel.

The 2001 rotor is surrounded by a stator with little curved hornlets protruding from each port. The intake is the large rectangular box the projector and stator are mounted on - its openings are located on the bottom. This is one reason the siren gives such a raspy sound.

In 2007, the 2001's air intake was elongated by a few inches - this was done to make the siren produce 130 decibels at 100 feet. Prior to this, the 2001-SRNB was rated at 128 decibels.

It's just a model 3 on it's side in a flower pot, that's really turning some RPMs.

They are really tough too. The siren heads rarely give trouble. Federal used a good motor in those sirens, most of the older ones had a Warfield, which is fairly high end. Only thing I've seen that can knock one out is a direct lightning strike on the head, or a car hitting the pole.

What brand of motor is used on the newer ?

Thank you all! I am VERY surprised knowing that they use a chopper. The pitch is so high! Low rpm maybe? I now have more respect for 2001's and 2001 130's! Thanks guys!

Just to point out: there are 2 tri motor sirens (thunderbolt and hurricane. Thunderbolt being first.) and I think 2 or so sirens that had 2 motors with blowers. (An old German siren and the Chrysler. Chrysler had a separate rotator platform and the blower was part of the head so I do not count it as a tri motor siren.)

coastalsyrolover wrote:Just to point out: there are 2 tri motor sirens (thunderbolt and hurricane. Thunderbolt being first.) and I think 2 or so sirens that had 2 motors with blowers. (An old German siren and the Chrysler. Chrysler had a separate rotator platform and the blower was part of the head so I do not count it as a tri motor siren.)

Would that German siren be the Hormann HLS 273?

http://www.federalsignal-indust.com/sit ... 102012.pdf

Just thought I would add that in. Once upon a time, when I was new to sirens, I wondered this question too I have heard this question multiple times, the way it looks can be misleading.