Media Informasi

AM stations were the earliest broadcasting stations to be developed. AM refers to amplitude modulation, a mode of broadcasting radio waves by varying the amplitude of the carrier signal in response to the amplitude of the signal to be transmitted. The medium-wave band is used worldwide for AM broadcasting. Europe also uses the long wave band. In response to the growing popularity of FM radio stereo radio stations in the late 1980s and early 1990s, some North American stations began broadcasting in AM stereo, though this never gained popularity, and very few receivers were ever sold.

FM refers to frequency modulation, and occurs on VHF airwaves in the frequency range of 88 to 108 MHz everywhere (except Japan and Russia). Japan uses the 76 to 90 MHz band. Russia has two bands widely used by the Soviet Union, 65.9 to 74 MHz and 87.5 to 108 MHz worldwide standard. FM stations are much more popular since higher sound fidelity and stereo broadcasting became common in this format. FM radio was invented by Edwin H. Armstrong in the 1930s for the specific purpose of overcoming the interference problem of AM radio, to which it is relatively immune. At the same time, greater fidelity was made possible by spacing stations further apart. Instead of 10 kHz apart, as on the AM band in the US, FM channels are 200 kHz (0.2 MHz) apart. In other countries greater spacing is sometimes mandatory, such as in New Zealand, which uses 700 kHz spacing (previously 800 kHz). The improved fidelity made available was far in advance...

The Broadcast type of radio network is a network system which distributes programming to multiple stations simultaneously, or slightly delayed, for the purpose of extending total coverage beyond the limits of a single broadcast signal. The resulting expanded audience for programming or information essentially applies the benefits of mass-production to the broadcasting enterprise. A radio network has two sales departments, one to package and sell programs to radio stations, and one to sell the audience of those programs to advertisers.

Internet radio (also known as web radio , net radio , streaming radio and e-radio ) is an audio service transmitted via the Internet. Music streaming on the Internet is usually referred to as webcasting since it is not transmitted broadly through wireless means. Internet radio involves streaming media, presenting listeners with a continuous stream of audio that cannot be paused or replayed, much like traditional broadcast media; in this respect, it is distinct from on-demand file serving. Internet radio is also distinct from podcasting, which involves downloading rather than streaming.

Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information. Originally, radio or radiotelegraphy was called "wireless telegraphy", which was shortened to "wireless" by the British. The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, coined...

Gelombang radio adalah satu bentuk dari radiasi elektromagnetik, dan terbentuk ketika objek bermuatan listrik dimodulasi (dinaikkan frekuensinya) pada frekuensi yang terdapat dalam frekuensi gelombang radio (RF) dalam suatu spektrum elektromagnetik, dan radiasi elektromagnetiknya bergerak dengan cara osilasi elektrik maupun magnetik. Gelombang elektromagnetik lainnya, yang memiliki frekuensi di atas gelombang radio meliputi sinar gamma, sinar-X, inframerah, ultraviolet, dan cahaya terlihat. Ketika gelombang radio dipancarkan melalui kabel, osilasi dari medan listrik dan magnetik tersebut dinyatakan dalam bentuk arus bolak-balik dan voltase di dalam kabel. Hal ini kemudian dapat diubah menjadi signal audio atau lainnya yang membawa informasi. Undang-undang Nomor 32 Tahun 2002 Tentang Penyiaran menyebutkan bahwa frekuensi radio merupakan gelombang elektromagnetik yang dipergunakan untuk penyiaran dan merambat di udara serta ruang angkasa tanpa sarana penghantar buatan, mer...

Banyak penggunaan awal radio adalah maritim, untuk mengirimkan pesan telegraf menggunakan kode Morse antara kapal dan darat. Salah satu pengguna awal termasuk Angkatan Laut Jepang memata-matai armada Rusia pada saat Perang Tsushima di 1901.  Salah satu penggunaan yang paling dikenang adalah pada saat tenggelamnya RMS Titanic pada 1912, termawuk komunikasi antara operator di kapal yang tenggelam dan kapal terdekat, dan komunikasi ke stasiun darat mendaftar yang terselamatkan. Radio digunakan untuk menyalurkan perintah dan komunikasi antara Angkatan Darat dan Angkatan Laut di kedua pihak pada Perang Dunia II; Jerman menggunakan komunikasi radio untuk pesan diplomatik ketika kabel bawah lautnya dipotong oleh Britania. Amerika Serikat menyampaikan Empat belas Pokok Presiden Woodrow Wilson kepada Jerman melalui radio ketika perang. Siaran mulai dapat dilakukan pada 1920-an, dengan populernya pesawat radio, terutama di Eropa dan Amerika Serikat. Selain siaran, siaran titik-k...