Medium wave (MW) is a part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the daytime, reception is usually limited to more local stations, though this is dependent on the signal conditions and quality of radio receiver used. Improved signal propagation at night allows the reception of much longer distance signals. This can cause increased interference because on most channels multiple transmitters operate simultaneously worldwide. In addition, amplitude modulation (AM) is often more prone to interference by various electronic devices, especially power supplies and computers. Strong transmitters cover larger areas than on the FM broadcast band but require more energy and longer antennas. Digital modes are possible but have not reached momentum yet.
Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination.
The Sender Donebach was a 500-kilowatt long wave radio transmitter operating on 153 kHz and transmitting the program of German public broadcaster Deutschlandfunk. The facility, which was the property of Media Broadcast, was built between 1965 and 1967 on a former airfield, and entered service on March 10, 1967.
Laser 558 was an offshore pirate radio station launched in May 1984 using disc jockeys from the US. It broadcast from the Panama-registered ship MV Communicator in international waters in the North Sea. Within months the station had a large audience, due to its strong signal and continuous music, mixing current records with oldies. However, insufficient advertising starved the station off the air in late 1985. In 1986 an attempt was made to return as Laser Hot Hits, but the same problems arose.
Radio City was a British pirate radio station broadcasting from Shivering Sands Army Fort, one of the abandoned Second World War Maunsell Sea Forts in the Thames Estuary.
Radio Veronica was an offshore radio station that began broadcasting in 1960, and was on air for over fourteen years. It was set up by independent radio, TV and household electrical retailers in the Netherlands, to stimulate the sales of radio receivers by providing an alternative to the Netherlands state-licensed stations in Hilversum.
Radio masts and towers are typically tall structures designed to support antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest human-made structures. Masts are often named after the broadcasting organizations that originally built them or currently use them.
A mast radiator is a radio mast or tower in which the metal structure itself is energized and functions as an antenna. This design, first used widely in the 1930s, is commonly used for transmitting antennas operating at low frequencies, in the LF and MF bands, in particular those used for AM radio broadcasting stations. The conductive steel mast is electrically connected to the transmitter. Its base is usually mounted on a nonconductive support to insulate it from the ground. A mast radiator is a form of monopole antenna.
A loop antenna is a radio antenna consisting of a loop or coil of wire, tubing, or other electrical conductor, that for transmitting is usually fed by a balanced power source or for receiving feeds a balanced load. Within this physical description there are two distinct types:
Voice of Peace was an offshore radio station that broadcast in the Middle East for 20 years from the former Dutch cargo vessel MV Peace, anchored off the Israeli coast in the Eastern Mediterranean. Founded by Abie Nathan and the New York-based Peace Ship Foundation, the station broadcast almost continuously between 19 May 1973 and November 1993. The station was relaunched but solely as an online station in August 2009. A second online channel called The Voice of Peace Classics was added in 2014.
The USCGC Courier (WAGR/WTR-410) was a cutter in the United States Coast Guard converted from the M/V Coastal Messenger a Maritime Commission Type C1-M-AV1 vessel.
Radio Nord was a Swedish offshore commercial station that operated briefly from 8 March 1961 to 30 June 1962 from a ship anchored in international waters of the Baltic Sea off Stockholm, Sweden. While the station was dubbed as a pirate radio station, its actual operation took place within the laws of the day and its offices were located in the heart of Stockholm. Its ownership was vested in a company which had been specifically formed by Texas broadcasting and political interests that included Gordon McLendon and Clint Murchison Jr.
MV Ross Revenge is a radio ship, the home of Radio Caroline, as well as having supported Radio Monique and various religious broadcasters. Funded by the Icelandic government, she was constructed in Bremerhaven in 1960 and served as an Icelandic commercial trawler until 1963 when she was sold to the Ross Group fleet, notably taking part in the Cod Wars of the 1970s. Following her decommissioning, she was purchased by Radio Caroline and outfitted as a radio ship, complete with 300-foot (91 m) antenna mast and 50 kW transmitter. Her broadcasts began on 20 August 1983; her final pirate broadcast took place in November 1990. She ran aground on the Goodwin Sands in November 1991, bringing the era of offshore pirate radio in Europe to an end. She was, however, salvaged, and is now maintained by the Caroline Support Group, a group of supporters and enthusiasts.
Radio Caroline is a British radio station founded in 1964 by Ronan O'Rahilly and Alan Crawford initially to circumvent the record companies' control of popular music broadcasting in the United Kingdom and the BBC's radio broadcasting monopoly. Unlicensed by any government for most of its early life, it was a pirate radio station that never became illegal as such due to operating outside any national jurisdiction, although after the Marine, &c., Broadcasting (Offences) Act 1967 it became illegal for a British subject to associate with it.
An umbrella antenna is a capacitively top-loaded wire monopole antenna, consisting in most cases of a mast fed at the ground end, to which a number of radial wires are connected at the top, sloping downwards. One side of the feedline supplying power from the transmitter is connected to the mast, and the other side to a ground (Earthing) system of radial wires buried in the earth under the antenna. They are used as transmitting antennas below 1 MHz, in the MF, LF and particularly the VLF bands, at frequencies sufficiently low that it is impractical or infeasible to build a full size quarter-wave monopole antenna. The outer end of each radial wire, sloping down from the top of the antenna, is connected by an insulator to a supporting rope or cable anchored to the ground; the radial wires can also support the mast as guy wires. The radial wires make the antenna look like the wire frame of a giant umbrella hence the name.
Radio North Sea International was a European offshore radio station run by the Swiss firm Mebo Telecommunications, jointly owned by Swiss engineer Edwin Bollier and his business partner, Erwin Meister. RNI broadcast for less than five years in the early 1970s and, courting both disaster and success, made a modest financial profit.
Radio Atlantis was a Belgian-owned offshore pirate radio station, which operated in 1973 and 1974 from the coast of The Netherlands and Belgium. The station began broadcasting from the Radio Caroline ship MV Mi Amigo on 15 July 1973. The station was owned by Belgian businessman Adriaan van Landschoot who ran a chain of companies all named Carnaby:
NPO Radio 5 is a Dutch public-service network radio station operated by NPO. Its main format is classic hits from the 1950s and beyond, with a much stronger emphasis from the 1960s to 1980s. Very rarely, songs from the late-1940s may air at times. The service targets 55-year-olds and older, in contrast to that of Radio 2 (35–55) and 3FM (15–35). Every year towards the end of November, NPO Radio 5 broadcasts "The Evergreen Top 1000".
The MV Nordeney was from November, 1964 until 31 August 1974 the transmission ship for offshore radio station Radio Veronica.
In radio systems, many different antenna types are used whose properties are especially crafted for particular applications. Most often, the greatest effect is due to the size (wavelength) of the radio waves the antenna is to intercept or produce; one competing second effect is differences in optimization for receiving and for transmitting; another competing influence is the number and bandwidth of the frequenc(y/ies) that any single antenna must intercept or emit.
