A civil defense siren (also known as an air-raid siren) is a siren used to provide an emergency population warning to the general population of approaching danger. It is sometimes sounded again to indicate the danger has passed. Initially designed to warn city dwellers of air raids in World War II. The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies.
A mechanical siren generates sound by spinning a slotted chopper wheel to interrupt a stream of air at a regular rate. Modern sirens can develop a sound level of up to 135 decibels at 100 feet (30 m).
By use of varying tones or binary patterns of sound, different alert conditions can be signaled. Electronic sirens can transmit voice announcements in addition to alert tone signals. Siren systems may be electronically controlled and integrated into other warning systems.
During the siege of Leningrad, ISSR, the radio network carried information for the population about raids and air alerts. The famous "metronome" went down in the history of the siege of Leningrad as a cultural monument of resistance of the population.
At that time , there were more than 1 thousand loudspeakers and 400 thousand radio streams operating in the city. If there were no broadcast programs, then the metronome was broadcast with a slow rhythm of 50-55 beats per minute. The network was switched on around the clock, which allowed the population and services to be confident in the operation of the network. By order of the MPVO headquarters, the duty officer of the Central station of the radio network interrupted the broadcast of the program, turned on an electric player with a record of the alarm text. This record was supplemented by 400 electric sirens. At the end of the recording, the metronome was switched on with a rapid rhythm of 160-180 beats per minute. When the danger was over, the electric player was switched on again by order of the staff , and the alarm was sounded in the streets and houses, accompanied by the sound of fanfares.
Today, at about 10:37, all over St Petersburg, Russia, there will be a Civil Defense Siren Check.
Let’s check it out too.
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#live #civildefense #siren
A mechanical siren generates sound by spinning a slotted chopper wheel to interrupt a stream of air at a regular rate. Modern sirens can develop a sound level of up to 135 decibels at 100 feet (30 m).
By use of varying tones or binary patterns of sound, different alert conditions can be signaled. Electronic sirens can transmit voice announcements in addition to alert tone signals. Siren systems may be electronically controlled and integrated into other warning systems.
During the siege of Leningrad, ISSR, the radio network carried information for the population about raids and air alerts. The famous "metronome" went down in the history of the siege of Leningrad as a cultural monument of resistance of the population.
At that time , there were more than 1 thousand loudspeakers and 400 thousand radio streams operating in the city. If there were no broadcast programs, then the metronome was broadcast with a slow rhythm of 50-55 beats per minute. The network was switched on around the clock, which allowed the population and services to be confident in the operation of the network. By order of the MPVO headquarters, the duty officer of the Central station of the radio network interrupted the broadcast of the program, turned on an electric player with a record of the alarm text. This record was supplemented by 400 electric sirens. At the end of the recording, the metronome was switched on with a rapid rhythm of 160-180 beats per minute. When the danger was over, the electric player was switched on again by order of the staff , and the alarm was sounded in the streets and houses, accompanied by the sound of fanfares.
Today, at about 10:37, all over St Petersburg, Russia, there will be a Civil Defense Siren Check.
Let’s check it out too.
???? To get a guaranteed response - send Superchat to contribute these live streams.
????PayPal - https://bit.ly/30F89jA
????Support the new road trips at http://realrussiablog.com/roadtrip
???? Join PATREON to support the channel - http://patreon.com/realrussia
????Instagram: http://instagram.com/sergeybaklykov
#live #civildefense #siren
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