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  2. Civil defense siren - Wikipedia

    en.wikipedia.org/wiki/Civil_defense_siren

    Sound sample ⓘ A civil defense siren is a siren used to provide an emergency population warning to the general population of ... Sound of the water-alarm signal ...

  3. Siren (alarm) - Wikipedia

    en.wikipedia.org/wiki/Siren_(alarm)

    Electronic Sirens Pavian by Telegrafia A Whelen WPS electronic siren imported to Saudi Arabia by HSS Engineering for use as a civil defense siren. There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday in February. [1] Sound sample ⓘ An 1860s-era siren. [2]

  4. List of sirens built by Alerting Communicators of America

    en.wikipedia.org/wiki/List_of_sirens_built_by...

    Sound Output and Type Notes BN52 - BN54 Gas-Mechanical 25 8 1942–1953 Rotating 125 dB at 100 ft. The first version of the Mobil Directo which used a 25HP Wisconsin air-cooled engine. BN44E Electro-Mechanical 10 8, 10/12 1948–1967 Rotating 124 dB at 100 ft. The second version of the Mobil Directo which used a 10HP electric motor.

  5. Emergency population warning - Wikipedia

    en.wikipedia.org/wiki/Emergency_population_warning

    It consists in a modulated sound going up and down (up to 380 Hz) during the first minute, and repeated three times. The end of alert is a continuous signal lasting 30 seconds. The system is tested the first Wednesday of every month at 11.45 in the north, 12.00 in the center, and at 12.15 in the south; for tests, the modulated signal is played ...

  6. List of civil defense sirens - Wikipedia

    en.wikipedia.org/wiki/List_of_civil_defense_sirens

    Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Help; Learn to edit; Community portal; Recent changes; Upload file

  7. Warning system - Wikipedia

    en.wikipedia.org/wiki/Warning_system

    A HSS Engineering TWS 295 electronic sirens warning Civil Defense siren. There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday in February. [1] Sound sample ⓘ Warning light indicating danger of laser exposure

  8. ACA Hurricane - Wikipedia

    en.wikipedia.org/wiki/ACA_Hurricane

    The ACA Hurricane is an electro-mechanical and rotating-directional, 130dB civil defense siren, created and produced by Alerting Communicators of America (ACA). ACA began manufacturing the Hurricane 130 in 1968, and ended production in 1981. The Hurricane 130 is very similar to the Federal Signal Thunderbolt series, being a supercharged siren.

  9. CONELRAD - Wikipedia

    en.wikipedia.org/wiki/CONELRAD

    CONELRAD (Control of Electromagnetic Radiation) was a method of emergency broadcasting to the public of the United States in the event of enemy attack during the Cold War.It was intended to allow continuous broadcast of civil defense information to the public using radio stations, while rapidly switching the transmitter stations to make the broadcasts unsuitable for Soviet bombers that might ...