Some of us may already be familiar with the term FM radio. Which type of radio is the least used by so many people. However, there are still a number of other types of radio. Here are some types of radios that exist, between different:
AM radio (amplitude modulation) works with the principle of modulating radio waves and audio waves. These two waves have the same constant amplitude. But this modulation process then replace the amplitude of wave conductor (radio) match the amplitude of the audio wave.
Initially the use of AM radio solely for the needs of wireless telegram. The one man who worked on a radio broadcast with a human voice was Reginald Aubrey Fessenden. He worked on a one-man radio broadcast on human voice on December 23, 1900 at a distance of 50 miles (from Cobb Island to Arlington, Virginia). Currently AM radio is not too little used for commercial radio broadcasts because of poor sound quality.
FM radio (frequency modulation) works on the same principle as AM radio, by modulating radio waves (conducting) with audio waves. Only, on the FM radio this modulation process resulted in changes in frequency. When AM radio is commonly used, Armstrong pursues that the radio difference problem lies in the type of signal being transmitted. At that time the audio wave is transmitted with radio waves by using amplitude modulation (AM).
This modulation is most vulnerable to weather disturbances. In the late 1920s Armstrong began working on modulation in which the amplitude of the conductor wave (radio) was created constant. In 1933 he finally pursue a frequency modulation system (FM) that produces much clearer sound, and is not distracted by bad weather.
Unfortunately this technology is not necessarily used in bulk. The economic depression of the 1930s resulted in the radio industry refusing to adopt this new system because it required the replacement of transmitters and receivers that cost less. New in 1940 Armstrong was able to establish an FM radio station at his own expense.
Two years later the Federal Communications Commission (FCC) allocated a number of frequencies to FM Armstrong’s radio station. It takes a long time for frequency modulation to become a widely used system. In addition to these patents are not obtained by Armstrong.
Frustrating all the obstacles in fighting for the FM system, Armstrong completed his life tragically with suicide techniques. Lucky his wife then successfully fight for Armstrong rights for his invention. It was not until the late 1960s that FM became a truly established system. Nearly 2000 FM radio stations spread across America, FM became a microwave supporter, in the end FM is really declared as a flagship system in many communications fields.
The invention of the Internet began to process the transmission of analog signals used by conventional radios. Internet radio (also known as web radio, streaming radio and e-radio) works with the technique of transmitting sound waves over the internet. The principle works almost the same with the short wave conventional radio (short wave), namely by using a continuous stream medium wave.
This working system allows radio broadcasts to be broadcast to all the world as long as the listener has an internet device. That’s why not a few expatriates who use internet radio to cultivate a sense of missed country of origin. In Indonesia, internet radio is usually collaborated with analog radio system by terrestrial radio station to broaden its broadcasting coverage.
Satellite radio transmits audio waves using digital signals. Unlike analog signals that use continuous waves, sound waves are transmitted across digital signals consisting of binary codes 0 and 1. These signals are transmitted to a much wider range of areas because they use satellites. It’s just that radio broadcasts can only be received by special equipment that can translate encrypted signals.
Satellite radio broadcasts can only be received in open locations where the antenna on the radio plane has a line of sight with the transmitting satellite. Satellite radio can only work that does not have a big barrier like a tunnel or building. Therefore satellite radio devices are not promoted for a little car radio. To get a good broadcast transmission, we need to create repeater stations like in America so that the quality of service excellence.
Expensive devices (because of using satellites) create this system commercially. Listeners must subscribe in order to pay attention to radio broadcasts. Even so the sound quality obtained is very clear, no longer no noise like conventional radio broadcasts. In addition, most of the content of the broadcast is free of ads and listeners have far less choice of broadcast channels (more than 120 channels).
Worldspace satellite radio provider that serves satellite radio broadcasting in America, Europe, Asia, Australia, and Africa. Worldspace has three satellites serving different districts. In Indonesia, until 2002 Worldspace has been working with RRI, Trijaya Radio, Borneo Wave Channel (Masima Group), goindo.com and Kompas Cyber Media as a filler of satellite radio services using the Asia Star satellite.
High-definition radio (HD Radio)
Radio is also known as a digital radio is working by combining analog and digital systems at once. That way allows two analog and digital stations to share the same frequency. This efficiency makes little content can be broadcast in the same position. The sound quality obtained by HD radio is as clear as satellite radio, but the services offered are free. But in order to receive a digital radio broadcast the listener must have an exclusive device that can capture digital signals.
Well, so is the explanation of the history and the types of radio. It turns out that radio is one communication device that is arguably the oldest in the world. This is evident from the explanation of the history above.
And even the radio has not a few types of opposites and of course also have the benefits and techniques of each work as has been described. Hopefully this paper can work for us all who read it.