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Warning Siren Terms

Chopper
The ring-shaped piece of metal with holes around the rim that helps give the siren its tone(s).
 
Intake
The opening typically found at the bottom of the siren where air is sucked into the siren to help spin the Chopper
 
Blower
A large, motor and belt-driven mechanism often housed in a large metal box that is basically the early equivalent of the Intake from later sirens
 
Rotator
The mechanism that allows the siren head to turn using some form of a motor
 
Stator
Slots generally at the back of the siren's head
 
Collector Rings
Metal rings used for brushes to ride on and generate electricity to the rest of the siren
 
Solenoids
Block-shaped pieces of metal that slide on metal rods and block one or even both openings to the chopper, allowing for different siren tones
 
Intake Valve
A large metal disk that opens and closes in response to Solenoids being activated.
 
Wail/Attack
The rising and falling sound often heard during severe weather or during actual air raids
 
Alert
The steady tone usually used for testing the siren and/or severe weather days.
 
Air Horn
Siren sound that is similar to a car horn that ocurrs in short bursts
 
Hi-Lo
Siren sound similar to emergency vehicle sirens in the UK that is generally used at fire stations
 
Hi-Lo
Siren sound similar to emergency vehicle sirens in the UK that is generally used at fire stations
 
Alternating Wail
Siren sound that combines the Wail and Hi-Lo tones together
 
Best Possible Protection
Siren sound where the sound rises and falls similarly to the Wail, but is much faster and intends to project the sound further than it normally would