The Siren Board

Mark N wrote:The 500AT rotor actually won't fit, I think its too big ir something.
I don't recall said thread, but if you can post a link, I'd love to read it.

The 500 has always been somewhat of a mystery for me. Obviously there is the short horn version, which was probably the loudest as it used the biggest rotor/stator. It's very obvious that they just stuck the STH-10 fan on it, as you can see the circles for the projectors on the stator on those models.

As far as the dual toned models, I think the one that sounds exactly like the 7T/SD-10 probably used the same parts as those two sirens did. Now the one that sounds like the 2T22, I haven't the slightest idea of what that actually looks like. If it was an entirely new rotor/stator specifically designed for the 500, then that might be the most unique thing Federal has ever done, and not recycled to or from any other siren they have ever produced. If it was a modified 5 rotor then I wonder why they didn't roll those into production with the 7T/SD-10..they sound WAY better.

To my understanding, the 500 series used a lot of interchangeable parts with other sirens, such as the aforementioned STH-10 rotor/stator. In fact, the 10/12 port rotor/stator is the only one that wasn't on any other siren. Ironically, I think it was the 10/12 port one that was the loudest-123 dB @ 100 feet. If anyone wants, I'll link up info.
So I guess the short answer is that you can use a Model 5 or Mobil Directo in place of a 2T22 chopper assembly, for the SD-10 project.

Yes, the early version of the single tone 500 used a STH-10 chopper and stator, you can see where the horns would go on the sides of the stator assembly. The later 500 model used a model 5 chopper/stator assembly as heard in this video:


https://www.youtube.com/watch?v=Rs-OIhdGlh8

They also made a single phase version of the 500, the one in Reedsburg is definitely a single phase version from the telltale slow windup. The 10/12 port 500AT used a 24" rotor and stator that is very very large compared to the other version. If you watch any video of the 10/12 version, (Byron, GA, Topeka, KS, Etc.) keep in mind that that is 15 horsepower motor. The other port combinations did not push the motor this bad.

Thanks people, my randomness has been satisfied! Mod you can lock this now.