This must've HURT! (It's been replaced by a normally mounted Whelen Omni of some sort) https://earth.google.com/web/search/+Menlo,+KS/@39.35480437,-100.72400908,898.91938314a,0d,60y,250.72474945h,101.34676044t,0r/data=CigiJgokCcIfeTEd70NAEam-GfpazkFAGaTHiZiAGlfAIRnQtG_3B1rAIhoKFk9GNXZ2RV9aS0lTZUdPLX...

They actually use a triangle wave with varying tones for all electronic sirens (Except Whelen, which uses square)

I calculated that Alertronics such as Odegen, IA are 740 HZ. Dual tones are 780/680 HZ. I would assume that the start frequency is half of the peak frequency, therefore:

Alertronics such as Odegen, IA:
Start: 370
Peak: 740

Dual tone Alertronics:
Start: 390/340
Peak: 780/680

It was found by 4j25 on his first siren hunting stream (Siren Hunting With 4j). And he said exactly that, "That's the highest Model 2 I've ever seen". I wonder how much trouble it was to install and hook up.

Sorry for the bump, but this HAS to qualify in the top 10: https://www.google.com/maps/@41.7932627,-92.0743459,3a,16.3y,279.79h,101.16t/data=!3m7!1e1!3m5!1svrWp_tnd2EkJQFWxHQTwfQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DvrWp_tnd2EkJQFWxHQTwfQ%26cb_client%3Dmap...

Here are the five lists of the most common sirens:

1: FS 2001-130, SRN, and SRNB.
2: All Whelens except the 3000, 2700, and 4008.
3: Sentry 10V, 3V8-H, 3V8, 7V8, 16V1T-B, 20V1T, and 15V1T.
4: Tempest 128 and 121.
5: FS Eclipse, 508-128, All Modulators & DSAs,and Model 2s.