Video of UT 1st siren Test..Good Vid.

[StonedChipmunk]

Are they actually effective, or are there multiple "blind spots"? I should go visit someday, just to see it. (Not! I've seen those enough in Hawaii...)

[Thunderbolt 612]

If a Thunderbolt produced this sound, then the rotor would be spinning at about 10,000 RPM!

[Robert Gift]

What is the rpm range at which Thunderbolt choppers may be set?

[Thunderbolt 612]

It varies with voltage, because of the terminal strip, which adjusts the voltage. So a Thunderbolt with a 10,000 RPM chopper would be set on a very high tap.

[Robert Gift]

How do they derive the different voltages?
Transformer taps?

So 10,000 rpm = 666 Hz if 4 port chopper
833 Hz 5 port chopper
creates a MAJOR third interval if both.

[Thunderbolt 612]

Don't forget 1000 hertz with 6 port chopper, and 665/835 being 4/5 would actually be a major third.

[Robert Gift]

Don't forget 1000 hertz with 6 port chopper, and 665/835 being 4/5 would actually be a major third.

You're right!
I can't even correctly read my own Ports, Pitches, Resultants compilation post. Thanks,

[Thunderbolt 612]

I looked at one of the sirens in the night, and it was ominous looking. Add the sound to it and that can start up some nightmares.

[Thunderbolt 612]

Well, it's already official, since Federal Warning Systems has news on the warning system up on their site.

Link:
http://www.federalwarningsystems.com/ne ... php?id=921