CONELRAD

CONELRAD (Control of Electromagnetic Radiation) is a former 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 or TV stations, while rapidly switching the transmitter stations to make the broadcasts unsuitable for Soviet bombers that might attempt to home in on the signals (as was done during World War II, when German radio stations, based in or near cities, were used as beacons by pilots of bombers).

U.S. president Harry S. Truman established CONELRAD in 1951. After the development of intercontinental ballistic missiles reduced the likelihood of a bomber attack, CONELRAD was replaced by the Emergency Broadcast System (EBS) on August 5, 1963, which was later replaced with the Emergency Alert System (EAS) on January 1, 1997; all have been administered by the Federal Communications Commission (FCC).

Unlike the EBS and EAS, CONELRAD was never intended to be used for local civil emergencies such as severe weather.

Prior to 1951, there was no systematic way for the U.S. government to communicate with citizens during an emergency. However, broadcasters would typically interrupt normal programming to issue emergency bulletins, as happened during the attack on Pearl Harbor on December 7, 1941 and the first successful tornado warning in 1948. Such bulletins were the forerunner to CONELRAD.

The CONELRAD concept was originally known as the Key Station System. According to an FCC document created during the "Informal Government–Industry Technical Conference" on March 26, 1951:

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