History of Radio

The history of radio is the history of technology that produces radio equipment that uses radio waves. Initially, signals on radio broadcasts were transmitted via continuous data waves either through amplitude modulation (AM) or frequency modulation (FM). This method of sending signals is called analog. Furthermore, along with the development of technology, the internet was discovered, and digital signals which then changed the way radio signals are transmitted

History of Radio Use

Many of radio's early uses were maritime, for sending telegraphic messages using Morse code between ships and land. One of its early uses included the Japanese Navy spying on the Russian fleet during the Battle of Tsushima in 1901. One of its most memorable uses was during the sinking of the RMS Titanic in 1912, including communication between operators on board the sunken ship and nearby ships and communications to ground station. Radio was used to pass on orders and communications between the Army and Navy on both sides in World War II; Germany used radio communications for diplomatic messages when its submarine cables were cut by the British. The United States relayed President Woodrow Wilson's 14 Point Program to Germany by radio during the war. Broadcasting began in the 1920s, with the popularity of radio sets, especially in Europe and the United States.

In addition to broadcasting, point-to-point broadcasting, including telephone and rebroadcasting of radio programs, became popular in the 1920s and 1930s. The pre-war use of radio was to improve the detection and location of aircraft and ships with the use of radar. Today, radio takes many forms, including wireless networks, mobile communications of all types, as well as radio broadcasting. Before television became popular, commercial radio broadcasts included drama, comedy, various shows, and many other forms of entertainment; not only news and music.

Radio AM

AM radio (amplitude modulation) works on the principle of modulating radio waves and audio waves. Both of these waves have a constant amplitude. However, this modulation process then changes the amplitude of the conducting (radio) wave according to the amplitude of the audio wave.

In 1896 the Italian scientist, Guglielmo Marconi received a patent for a wireless telegraph using two circuits. At that time this signal could only be sent over short distances. However, this is what started the development of radio technology. In 1897 Marconi again published his discovery that wireless signals could be transmitted over longer distances (12 miles). Furthermore, in 1899 Marconi succeeded in making wireless communication between France and England via the English Channel using the Tesla oscillator.

John Ambrose Fleming in 1904 discovered that audio tubes could be used as wireless receivers for this radio technology. Two years later Dr. Lee deForest invented the electron tube consisting of three elements (triode audion). This invention made it possible for sound waves to be transmitted via wireless communication systems. But the captured signal is still very weak. It was only in 1912 [[Edwin Howard Armstrong discovered a radio wave amplifier also called a radio amplifier. This tool works by capturing electromagnetic signals from radio transmissions and providing a return signal from the tube. That way the signal strength will increase as much as 20,000 times per second. The captured sound is also much stronger so that it can be heard directly without using earphones. This discovery then becomes very important in radio communication systems because it is much more efficient than previous tools. Nevertheless, the patent on the amplifier fell into the hands of Dr. Lee de forest. Until now, radio amplifier is still the core technology in radio equipment.

Initially, the use of AM radio was only for wireless telegram purposes. The first person to broadcast radio with a human voice was Reginald Aubrey Fessenden. He made the first radio broadcast with a human voice on December 23, 1900, at a distance of 50 miles (from Cobb Island to Arlington, Virginia). Today AM radio is not used too much for commercial radio broadcasts because of the poor sound quality.

Radio FM

FM radio (frequency modulation) works on a principle similar to AM radio, namely by modulating radio waves (conductor) with audio waves. It's just that, on FM radio this modulation process causes a change in frequency.

When AM radio became common, Armstrong discovered that another problem with radio lay in the type of signal being transmitted. At that time audio waves were transmitted along with radio waves using amplitude modulation (AM). This modulation is very vulnerable to weather disturbances. In the late 1920s, Armstrong began trying to use modulation where the amplitude of the conducting (radio) wave was kept constant. In 1933 he finally found a frequency modulation (FM) system that produced a much clearer sound and was not disturbed by bad weather.

Unfortunately, this technology is not necessarily used en masse. The economic depression of the 1930s made the radio industry reluctant to adopt this new system because it required the costly replacement of transmitters and receivers. It wasn't until 1940 that Armstrong was able to set up the first FM radio station at his own expense. Two years later the Federal Communications Commission (FCC) allocated some frequencies to the FM radio station that Armstrong had built. It took a long time for frequency modulation to become a widely used system. In addition, Armstrong never obtained a patent.

Frustrated by all the difficulties in fighting for the FM system, Armstrong ended his life tragically by committing suicide. Luckily his wife then managed to fight for Armstrong's rights to his invention. It was only in the late 1960s that FM became a truly established system. With nearly 2000 FM radio stations spread across America, FM became a supporter of microwaves (microwave), in the end, FM was truly recognized as a superior system in various fields of communication.

Internet radio

The invention of the internet started to change the analog signal transmission used by the conventional radio. Internet radio (also known as web radio, streaming radio, and e-radio) works by transmitting sound waves over the internet. The working principle is almost the same as conventional short-wave radio, namely by using a streaming medium in the form of a continuous wave. This working system allows radio broadcasts to be heard throughout the world as long as the listener has an internet device. That is why many expatriates use internet radio to relieve their homesickness. In Indonesia, generally, internet radio collaborated with an analog radio system by terrestrial radio stations to expand their broadcast reach.

Satellite Radio

Satellite radio transmits audio waves using digital signals. Unlike analog signals that use continuous waves, sound waves are transmitted via digital signals consisting of binary 0 and 1 codes. This signal is transmitted to a much wider coverage area because it uses satellites. It's just that radio broadcasts can only be received by special devices that can decode encrypted signals. Satellite radio broadcasts can also only be received in open areas where the antenna on the radio is in line of sight with the transmitting satellite. Satellite radio will only work where there are no major obstructions such as tunnels or buildings. Therefore satellite radio devices are widely promoted for car radios. To get good broadcast transmission, it is necessary to make repeater stations like in America so that the service quality is excellent.

Expensive equipment (because it uses satellites) makes this system commercial. Listeners must subscribe to be able to listen to radio broadcasts. Even so, the sound quality produced is very clear, there is no noise like in conventional radio broadcasts. In addition, most of the broadcast content is ad-free and listeners have a much wider choice of broadcast channels (more than 120 channels).

The world's satellite radio provider company is Worldspace which serves satellite radio broadcasts in America, Europe, Asia, Australia, and Africa. Worldspace has three satellites serving different regions. In Indonesia, until 2002 Worldspace collaborated with RRI, Trijaya Radio, Borneo Wave Channel (Masima Group), goindo.com, and Kompas Cyber ​​Media as content fillers for satellite radio services using the Asia Star satellite. mbs fm Suci manyar Gresik

High-definition radio (HD Radio)

Radio, also known as digital radio, works by combining analog and digital systems as well. This allows two digital and analog stations to share the same frequency. This efficiency allows multiple contents to be broadcast in the same position. The sound quality produced by HD radio is as clear as satellite radio, but the service is offered free of charge. However, to be able to receive digital radio broadcasts, listeners must have a special device that can capture digital signals.

Sumber : http://id.wikipedia.org/