ACA Cyclone

The ACA Cyclone is an outdoor warning siren built by Alerting Communicators of America (ACA) — now American Signal Corporation — in 1968.

History

The Cyclone was designed in 1968 by Jim Biersach. It is an omni directional, dual tone siren that was primarily intended for Civil Defense warning purposes, but was and is currently used for other outdoor warning purposes.

The first version of the Cyclone was called the Cyclone 120. This siren used a 40-horsepower motor, and produced a sound output of 120 dB at a distance of 100 ft.

In 1980, the Cyclone was redesigned and renamed the Cyclone 125. It received a new rotor/stator assembly and a new 50 horsepower motor. These changes raised sound output to 125 dB at 100 feet. The Cyclone 125 also featured some cosmetic changes to accommodate the new rotor/stator and motor.

Technical information

Years	Type	Motor HP	Rotor/Stator interval	Notes
1968–1970	Cyclone 120	40 HP	8-12 port	Uses a stator with angled bottom-row ports that went on to be used in the P-50 rotating siren. Only one Cyclone 120 of this version is known to exist, and is still active in New Richmond, Minnesota.
1970–1980	Cyclone 120	50 HP	8-12 port	Stator intake has a large air valve underneath it.
1980-2007	Cyclone 125	50 HP	8-12 port	Parallel stator, increased the decibel rating by 5. No longer in production.