Radio broadcasting has a long history; One that goes beyond Tesla, Marconi and Armstrong, and it includes advances in communication and technology, as explained by Radio magazine. Some of the important dates from radio's past are covered on the AmericanRadioHistory.com website. There, one can read about the earliest forms of radiotelegraphy systems.
In fact, early 1920s marks an important date in time of radio telegraph communication: In that time, the basis of public radio network broadcasting and even early TV programming were provided: Scientists were experimenting in 1925 with TVs, to include video content distributed via radio Transmissions on designated channels to a dispensed audience.
Early audio transmission set in motion AM broadcasting on a radio station. To overcome the interference problems of AM radio, stations began to use FM radio in the 1930s as its band provided a more clear-cut audio sound through the air as radio waves from a transmitter to an antenna. It was not until the 2000s that Americans were introduced to digital radio and direct broadcasting by satellite (DBS).
By the 1930s, radio broadcasting and television broadcasting (telecasting) was an integral part of the American way of life.
In the previous decade, the 1920s, early amateur radio transmitted information in the form of Morse code; A series of on-off tones provided communication on telegraph lines, undersea cables and radio circuits for transmitting emergency signals. Radio telegraphy using Morse code proved vital during World War II. Also Mayday calls were made by radio to signal a life-threatening emergency. A fire, an explosion or sinking vessel or aircraft, where announced with a signal transmitted three times in a row ("Mayday Mayday Mayday"); The distress call was broadcasted to reach out for assistance in times of an emergency.
A device dubbed the ham radio was used for amateur radio broadcasting early on; A range of frequencies (set aside for commercial, police and government use only) allowed one-and two-way communication by the 1940s. The ham radio happened to be something of an emergency broadcast system to get the word out to the wider community in the event of an emergency, such as a natural disaster. The SOS (amateur distress call) sent by the Titanic had used a radio ham in April 1912, noted ARRL (American Radio Relay League), the national association for Amateur Radio, on its webpage on "Ham Radio History."
In the 1950s, CONELRAD (Control of Electromagnetic Radiation) was a method of emergency broadcasting to the public; The CONELRAD system (used during the Cold War) was replaced by the Emergency Broadcast System (EBS) in the 60s, which was later replaced with the Emergency Alert System (EAS) in the 90s. Regardless of the name change, each one served as a national warning system for the American public in the event of war or grave national crisis, in addition to local weather emerging. Such broadcasting systems had a vital role in emergencies to quickly provide the necessary alert and message to a community when a catastrophic situation is exposed. In essence, it announced an emergency broadcast response which could potentially save human lives and deliver instructions if an evacuation was required.
To this day, radio broadcasting has been the most utilized media to distribute to the public civil emergency messages.
In history, it has been widely accepted as the mass communication medium for information, especially during times of severe weather and even threats related to wars. In fact, radio communication can be sustained even when other means of communication fail and there is no power. In addition, it is a media everyone has access to. Transmitting real-time warnings to citizens in the event of an emergency proves that communications devices like radios can still be of great importance, today, in emergencies even in the era of computers and mobile devices.