Radio call sign

In broadcasting and radio communications, a call sign (also known as a callsign, callname or call letters, or abbreviated as a call) is a unique designation for a transmitting station. In some countries they are used as names for broadcasting stations, but in many other countries they are not. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even cryptographically encoded to disguise a station’s identity.

The use of callsigns as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two letter identifiers were adopted for this purpose. This pattern continued in radiotelegraph operation; radio companies initially assigned two-letter identifiers to coastal stations and stations aboard ships at sea. These were not globally unique, so a one-letter company identifier (for instance, ‘M’ and two letters as a Marconi Station) was later added. By 1912, the need to quickly identify stations operated by multiple companies in multiple nations required an international standard; an ITU prefix would be used to identify a country, and the rest of the callsign an individual station in that country.

Sejak kebelakangan ini, aku sering mencari informasi pasal benda alah ini. Tetiba rasa berminat untuk menjadikan ianya satu hobi. Tadi pagi aku berbual dengan seseorang yang berkecimpung dalam bidang ini, dan ujian untuk radio call sign sudah ditutup. Tapi, untuk ujian bulan 12, kalau tidak ada aral melintang, aku akan cuba mengambil ujian tersebut.