Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz, using channels spaced every 9 kHz, and in North America an extended MW broadcast band ranges from 525 kHz to 1705 kHz, using 10 kHz spaced channels. The term is a historic one, dating from the early 20th century, when the radio spectrum was divided on the basis of the wavelength of the waves into long wave (LW), medium wave, and short wave (SW) radio bands.
Wavelengths in this band are long enough that radio waves are not blocked by buildings and hills and can propagate beyond the horizon following the curvature of the Earth; this is called the groundwave. Practical groundwave reception typically extends to 200–300 miles, with greater distances over terrain with higher ground conductivity, and greatest distances over salt water. Most broadcast stations use groundwave to cover their listening area.
Medium waves can also reflect off charged particle layers in the ionosphere and return to Earth at much greater distances; this is called the skywave. At night, especially in winter months and at times of low solar activity, the lower ionospheric D layer virtually disappears. When this happens, MW radio waves can easily be received many hundreds or even thousands of miles away as the signal will be reflected by the higher F layer. This can allow very long-distance broadcasting, but can also interfere with distant local stations. Due to the limited number of available channels in the MW broadcast band, the same frequencies are re-allocated to different broadcasting stations several hundred miles apart. On nights of good skywave propagation, the skywave signals of a distant station may interfere with the signals of local stations on the same frequency. In North America, the North American Regional Broadcasting Agreement (NARBA) sets aside certain channels for nighttime use over extended service areas via skywave by a few specially licensed AM broadcasting stations. These channels are called clear channels, and they are required to broadcast at higher powers of 10 to 50 kW.
Initially, broadcasting in the United States was restricted to two wavelengths: "entertainment" was broadcast at 360 meters (833 kHz), with stations required to switch to 485 meters (619 kHz) when broadcasting weather forecasts, crop price reports and other government reports. This arrangement had numerous practical difficulties. Early transmitters were technically crude and virtually impossible to set accurately on their intended frequency and if (as frequently happened) two (or more) stations in the same part of the country broadcast simultaneously the resultant interference meant that usually neither could be heard clearly. The Commerce Department rarely intervened in such cases but left it up to stations to enter into voluntary timesharing agreements amongst themselves. The addition of a third "entertainment" wavelength, 400 meters, did little to solve this overcrowding.
In 1923, the Commerce Department realized that as more and more stations were applying for commercial licenses, it was not practical to have every station broadcast on the same three wavelengths. On 15 May 1923, Commerce Secretary Herbert Hoover announced a new bandplan which set aside 81 frequencies, in 10 kHz steps, from 550 kHz to 1350 kHz (extended to 1500, then 1600 and ultimately 1700 kHz in later years). Each station would be assigned one frequency (albeit usually shared with stations in other parts of the country and/or abroad), no longer having to broadcast weather and government reports on a different frequency than entertainment. Class A and B stations were segregated into sub-bands.
Today in most of the Americas, mediumwave broadcast stations are separated by 10 kHz and have two sidebands of up to ±5 kHz in theory. In the rest of the world, the separation is 9 kHz, with sidebands of ±4.5 kHz. Both provide adequate audio quality for voice, but are insufficient for high-fidelity broadcasting, which is common on the VHF FM bands. In the US and Canada the maximum transmitter power is restricted to 50 kilowatts, while in Europe there are medium wave stations with transmitter power up to 2 megawatts daytime.
Most United States AM radio stations are required by the Federal Communications Commission (FCC) to shut down, reduce power, or employ a directional antenna array at night in order to avoid interference with each other due to night-time only long-distance skywave propagation (sometimes loosely called ‘skip’). Those stations which shut down completely at night are often known as "daytimers". Similar regulations are in force for Canadian stations, administered by Industry Canada; however, daytimers no longer exist in Canada, the last station having signed off in 2013, after migrating to the FM band.
In Europe, each country is allocated a number of frequencies on which high power (up to 2 MW) can be used; the maximum power is also subject to international agreement by the International Telecommunication Union (ITU). In most cases there are two power limits: a lower one for omnidirectional and a higher one for directional radiation with minima in certain directions. The power limit can also be depending on daytime and it is possible, that a station may not work at nighttime, because it would then produce too much interference. Other countries may only operate low-powered transmitters on the same frequency, again subject to agreement. For example, Russia operates a high-powered transmitter, located in its Kaliningrad exclave and used for external broadcasting, on 1386 kHz. The same frequency is also used by low-powered local radio stations in the United Kingdom, which has approximately 250 medium-wave transmitters of 1 kW and over; other parts of the United Kingdom can still receive the Russian broadcast. International mediumwave broadcasting in Europe has decreased markedly with the end of the Cold War and the increased availability of satellite and Internet TV and radio, although the cross-border reception of neighbouring countries' broadcasts by expatriates and other interested listeners still takes place.
Due to the high demand for frequencies in Europe, many countries operate single frequency networks; in Britain, BBC Radio Five Live broadcasts from various transmitters on either 693 or 909 kHz. These transmitters are carefully synchronized to minimize interference from more distant transmitters on the same frequency.
Overcrowding on the Medium wave band is a serious problem in parts of Europe contributing to the early adoption of VHF FM broadcasting by many stations (particularly in Germany). However, in recent years several European countries (Including Ireland, Poland and, to a lesser extent Switzerland) have started moving away from Medium wave altogether with most/all services moving exclusively to other bands (usually VHF).
In Germany, almost all Medium wave public-radio broadcasts were discontinued between 2012 and 2015 to cut costs and save energy, with the last such remaining programme (Deutschlandradio) being switched off on 31 December 2015.
In The Netherlands all national and regional medium wave stations (public and commercial) were discontinued between 2015 and 2018. The last station that powered down its medium wave transmitter was Groot Nieuws Radio on 31 December 2018. All stations that were broadcasting on medium wave are now using DAB+. All that is left on the medium wave is a handful of low powered medium wave radio stations (maximum output power is 100 W).
Stereo transmission is possible and offered by some stations in the U.S., Canada, Mexico, the Dominican Republic, Paraguay, Australia, The Philippines, Japan, South Korea, South Africa, Italy and France. However, there have been multiple standards for AM stereo. C-QUAM is the official standard in the United States as well as other countries, but receivers that implement the technology are no longer readily available to consumers. Used receivers with AM Stereo can be found. Names such as "FM/AM Stereo" or "AM & FM Stereo" can be misleading and usually do not signify that the radio will decode C-QUAM AM stereo, whereas a set labeled "FM Stereo/AM Stereo" or "AMAX Stereo" will support AM stereo.
In September 2002, the United States Federal Communications Commission approved the proprietary iBiquity in-band on-channel (IBOC) HD Radio system of digital audio broadcasting, which is meant to improve the audio quality of signals. The Digital Radio Mondiale (DRM) system standardised by ETSI supports stereo and is the ITU approved system for use outside North America and U.S. territories. Some HD Radio receivers also support C-QUAM AM stereo, although this feature is usually not advertised by the manufacturer.
For broadcasting, mast radiators are the most common type of antenna used, consisting of a steel lattice guyed mast in which the mast structure itself is used as the antenna. Stations broadcasting with low power can use masts with heights of a quarter-wavelength (about 310 millivolts per meter using one kilowatt at one kilometer) to 5/8 wavelength (225 electrical degrees; about 440 millivolts per meter using one kilowatt at one kilometer), while high power stations mostly use half-wavelength to 5/9 wavelength. The usage of masts taller than 5/9 wavelength (200 electrical degrees; about 410 millivolts per meter using one kilowatt at one kilometer) with high power gives a poor vertical radiation pattern, and 195 electrical degrees (about 400 millivolts per meter using one kilowatt at one kilometer) is generally considered ideal in these cases. Usually mast antennas are series-excited (base driven); the feedline is attached to the mast at the base. The base of the antenna is at high electrical potential and must be supported on a ceramic insulator to isolate it from the ground. Shunt-excited masts, in which the base of the mast is at a node of the standing wave at ground potential and so does not need to be insulated from the ground, have fallen into disuse, except in cases of exceptionally high power, 1 MW or more, where series excitation might be impractical. If grounded masts or towers are required, cage or long-wire aerials are used. Another possibility consists of feeding the mast or the tower by cables running from the tuning unit to the guys or crossbars at a certain height.
Directional aerials consist of multiple masts, which need not to be of the same height. It is also possible to realize directional aerials for mediumwave with cage aerials where some parts of the cage are fed with a certain phase difference.
For medium-wave (AM) broadcasting, quarter-wave masts are between 153 feet (47 m) and 463 feet (141 m) high, depending on the frequency. Because such tall masts can be costly and uneconomic, other types of antennas are often used, which employ capacitive top-loading (electrical lengthening) to achieve equivalent signal strength with vertical masts shorter than a quarter wavelength. A "top hat" of radial wires is occasionally added to the top of mast radiators, to allow the mast to be made shorter. For local broadcast stations and amateur stations of under 5 kW, T- and L-antennas are often used, which consist of one or more horizontal wires suspended between two masts, attached to a vertical radiator wire. A popular choice for lower-powered stations is the umbrella antenna, which needs only one mast one-tenth wavelength or less in height. This antenna uses a single mast insulated from ground and fed at the lower end against ground. At the top of the mast, radial top-load wires are connected (usually about six) which slope downwards at an angle of 40–45 degrees as far as about one-third of the total height, where they are terminated in insulators and thence outwards to ground anchors. Thus the umbrella antenna uses the guy wires as the top-load part of the antenna. In all these antennas the smaller radiation resistance of the short radiator is increased by the capacitance added by the wires attached to the top of the antenna.
In some rare cases dipole antennas are used, which are slung between two masts or towers. Such antennas are intended to radiate a skywave. The medium-wave transmitter at Berlin-Britz for transmitting RIAS used a cross dipole mounted on five 30.5-metre-high guyed masts to transmit the skywave to the ionosphere at nighttime.
Because at these frequencies atmospheric noise is far above the receiver signal to noise ratio, inefficient antennas much smaller than a wavelength can be used for receiving. For reception at frequencies below 1.6 MHz, which includes long and medium waves, loop antennas are popular because of their ability to reject locally generated noise. By far the most common antenna for broadcast reception is the ferrite-rod antenna, also known as a loopstick antenna. The high permeability ferrite core allows it to be compact enough to be enclosed inside the radio's case and still have adequate sensitivity.
AM broadcasting is a radio broadcasting technology, which employs amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmissions, but also on the longwave and shortwave radio bands.
The earliest experimental AM transmissions began in the early 1900s. However, widespread AM broadcasting was not established until the 1920s, following the development of vacuum tube receivers and transmitters. AM radio remained the dominant method of broadcasting for the next 30 years, a period called the "Golden Age of Radio", until television broadcasting became widespread in the 1950s and received most of the programming previously carried by radio. Subsequently, AM radio's audiences have also greatly shrunk due to competition from FM (frequency modulation) radio, Digital Audio Broadcasting (DAB), satellite radio, HD (digital) radio and Internet streaming.
AM transmissions are much more susceptible than FM or digital signals are to interference, and often have lower audio fidelity. Thus, AM broadcasters tend to specialise in spoken-word formats, such as talk radio, all news and sports, leaving the broadcasting of music mainly to FM and digital stations.BBC Radio Wales
BBC Radio Wales is BBC Cymru Wales's national English language radio station. It began broadcasting on 13 November 1978, following the demise of the 'Radio 4 Wales' service (previously the Welsh Home Service) and BBC Radio 4's transformation into a national network, moving from medium wave to long wave.
The station's managing editor is Colin Paterson.According to RAJAR, the station has a weekly audience of 316,000 listeners and a listening share of 4% as of December 2018.Boldur
Boldur (Hungarian: Boldor) is a commune in Timiș County, Romania. It is composed of four villages: Boldur, Jabăr (Zsábár), Ohaba-Forgaci (Temesforgács) and Sinersig (Szinérszeg).
Near Boldur, there is a medium-wave transmitter, which works on 756 kHz-400kw power- and uses an antenna consisting of 210 metres-tall guyed masts.Brendan Balfe
Brendan Balfe (born 19 September 1945 in Dublin) is an Irish radio personality, who has been on-air consistently for more than 40 years on RTÉ. Comedy has been a feature of many of Balfe's programmes. He has won three International Awards for radio comedy and his "Pathetic News" feature on Balfe Street, was the only original satire on Irish radio for many years.
He set an international Radio record (now broken) for a 12-hour broadcast as the story of the assassination of Robert Kennedy was unfolding.
Balfe served as the Irish spokesperson for the Eurovision Song Contest between 1974 and 1977. He also provided the RTÉ radio commentary for the 1983 Contest and provided the RTÉ television commentary for the 1986 Contest.
In 1986, Balfe won a Jacob's Award for his radio documentary series The Spice of Life.
From 1999 to 2010, Balfe was the Music Policy Co-ordinator for RTÉ Radio 1, responsible for the choice of contemporary music across the schedule and was the first ever voice on RTÉ 2fm.He published his autobiography, entitled Radio Man, in 2007.On 24 March 2008 Balfe hosted the last radio show to be broadcast on RTÉ's medium wave service, Medium Wave Goodbye, a personal selection of items broadcast on the service since 1926.Balfe retired from RTÉ in September 2010, following the final episode of his 11-part radio documentary series, The Irish Voice.Clyde 2
Clyde 2 is a local radio station serving Glasgow and West Central Scotland. The station broadcasts classic hits music output, alongside sport and specialist programming – it is part of Bauer's Greatest Hits network of AM stations in Scotland and northern England, carrying networked programming 24 hours a day alongside local news and information. Clyde 2 broadcasts on the medium wave on a frequency of 1152 kHz (equivalent wavelength: 261m), and on DAB in stereo.Domžale radio transmitter
The Domžale radio transmitter is a facility for medium wave broadcasting in Domžale, in Slovenia. The transmitter is fully transistorized. It could be received easily at a medium wave frequency of 918 kHz across the whole of Europe at night-time. It was the strongest radio transmitter of the Republic of Slovenia, broadcasting the first national radio channel.FM broadcasting in the UK
FM sound broadcasting began in the United Kingdom on 2 May 1955 when the BBC started an FM broadcasting service the Light Programme, the Third Programme and the Home Service to the south east of England. There are now over 40 BBC and over 250 commercial FM sound broadcasting stations in the United Kingdom.Kossuth Rádió
Kossuth Rádió (formerly known as MR1-Kossuth Rádió, Radio Budapest and Budapest I.) is the national radio station of Hungary. It was established in 1925 as Budapest I. and named after Lajos Kossuth, a Hungarian national hero, in 1849. The main Hungarian-language radio station can be heard all over Central Europe; Antenna Hungária broadcasts it with 2 MW power on 540 kHz AM from transmitter Solt (the most powerful medium wave transmitter in the world) and several FM stations, covering Hungary and the neighbouring countries. It is the second most popular radio station in Hungary (as 2013) with 1.38 million listeners (14% of the total population) daily.List of radio stations in Egypt
Radio broadcasting in Egypt began in the 20th century, in 1924 as privately owned and operated community stations. Later, in 1934 private ownership and operation were abolished and radio broadcasting was nationalized ever since.
By the early 1990s, Egypt had only 4 FM stations in Greater Cairo (2 in Alexandria), but the number increased to 6 in Greater Cairo (4 in Alexandria) by the end of the decade. The increase in the number was merely a rebroadcast of the already AM radio stations. In 2000, AM stations (on the medium wave band) started a phase of simulcasting to FM band, as of 2013, only one or two stations broadcast on AM without FM simulcasts.
All the local radio stations have always been publicly owned, however, state-controlled which make them in practice, stated owned, with the exception of the apolitical private radio station at El Gouna resort, named El Gouna Radio ("Lagoon Radio"). All broadcast media are somehow state controlled, even if partly or fully private.
As of 2002, there were only 8 radio stations broadcast on FM to Greater Cairo (6 in Alexandria), none of them was specialized in popular songs. On March 23, 2002, VOA had changed its shortwave Arabic service to an appealing station for the youth, named Radio Sawa ("Radio Together"), started broadcasting on a more easily receivable MW signal from Cyprus. For the first time, the state allowed Good News to start a joint venture with the state-controlled ERTU, which started a test broadcasting for two popular song stations to Greater Cairo, as of June 2002. The two were Nogoum FM ("Stars FM"; for popular mainly Egyptian songs) and Nile FM (for popular mainly American songs).Longwave
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the early 20th century, when the radio spectrum was considered to consist of longwave (LW), medium-wave (MW), and short-wave (SW) radio bands. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'.
In contemporary usage, the term longwave is not defined precisely, and its intended meaning varies. It may be used for radio wavelengths longer than 1,000 m i.e. frequencies up to 300 kilohertz (kHz), including the International Telecommunications Union's (ITU's) low frequency (LF, 30–300 kHz) and very low frequency (VLF, 3–30 kHz) bands. Sometimes the upper limit is taken to be higher than 300 kHz, but not above the start of the medium wave broadcast band at 525 kHz.In Europe, Africa, and large parts of Asia (International Telecommunication Union Region 1), where a range of frequencies between 148.5 and 283.5 kHz is used for AM broadcasting in addition to the medium-wave band, the term longwave usually refers specifically to this broadcasting band, which falls wholly within the low frequency band of the radio spectrum (30–300 kHz). The "Longwave Club of America" (United States) is interested in "frequencies below the AM broadcast band" (i.e., all frequencies below 525 kHz).Medium frequency
Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz). Part of this band is the medium wave (MW) AM broadcast band. The MF band is also known as the hectometer band as the wavelengths range from ten to one hectometer (1,000 to 100 m). Frequencies immediately below MF are denoted low frequency (LF), while the first band of higher frequencies is known as high frequency (HF). MF is mostly used for AM radio broadcasting, navigational radio beacons, maritime ship-to-shore communication, and transoceanic air traffic control.Premier Christian Radio
Premier Christian Radio is a British Christian radio station, part of Premier (a Christian communications organisation) which is in turn wholly owned by the charity Premier Christian Media Trust.
Premier Christian Radio broadcasts Christian programming including news, debate, teachings and Christian music across the United Kingdom.RTÉ Radio 1
RTÉ Radio 1 (Irish: RTÉ Raidió 1) is the principal radio channel of Irish public-service broadcaster Raidió Teilifís Éireann and is the direct descendant of Dublin radio station 2RN, which began broadcasting on a regular basis on 1 January 1926. The station is a rare modern example of a mixed radio channel, offering a wide spectrum of programming which is mainly speech-based but also includes a fair amount of music.
The total budget for the station in 2010 was €18.4 million. It is the most-listened-to radio station in Ireland.Radio broadcasting
Radio broadcasting is transmission by radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both.
The signal types can be either analog audio or digital audio.Rádio Renascença
Rádio Renascença, also known as 'RR' or just 'Renascença' (Renaissance in English), is a private, commercial radio station in Portugal, owned by various organizations within the Portuguese Catholic Church: among others, the Patriarchate of Lisbon. Founded in 1934, it began broadcasting in 1936. Renascença owns another three stations: RFM (the most listened-to radio station in the country), Mega Hits FM, and Rádio Sim (a channel aimed at listeners over 55).
Some programs, notably newscasts and religious events, are broadcast simultaneously on both Rádio Renascença and Rádio Sim.
Rádio Renascença is available in mainland Portugal on FM. Rádio Sim is available on medium wave, covering most of mainland Portugal, as well as on FM in some regions.
RR (Rádio Sim)'s most powerful medium-wave transmitter – operating on a frequency of 594 kHz with a power of 100 kW (although currently using 60 to 80 kW) – is situated near the village of Muge, some 75 km north-east of Lisbon. It is a 259-meter-high guyed mast radiator and also Portugal's tallest structure.Solt
Solt (Croatian: Šolta) is a town in Bács-Kiskun county, Hungary. Near Solt there is a high-power medium wave transmitter.Transmitter
In electronics and telecommunications, a transmitter or radio transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves.
Transmitters are necessary component parts of all electronic devices that communicate by radio, such as radio and television broadcasting stations, cell phones, walkie-talkies, wireless computer networks, Bluetooth enabled devices, garage door openers, two-way radios in aircraft, ships, spacecraft, radar sets and navigational beacons. The term transmitter is usually limited to equipment that generates radio waves for communication purposes; or radiolocation, such as radar and navigational transmitters. Generators of radio waves for heating or industrial purposes, such as microwave ovens or diathermy equipment, are not usually called transmitters, even though they often have similar circuits.
The term is popularly used more specifically to refer to a broadcast transmitter, a transmitter used in broadcasting, as in FM radio transmitter or television transmitter. This usage typically includes both the transmitter proper, the antenna, and often the building it is housed in.Vatican Radio
Vatican Radio (Italian: Radio Vaticana; Latin: Statio Radiophonica Vaticana) is the official broadcasting service of the Vatican.
Set up in 1931 by Guglielmo Marconi, today its programs are offered in 47 languages, and are sent out on short wave (also DRM), medium wave, FM, satellite and the Internet. Since its inception, Vatican Radio has been maintained by the Jesuit Order. Vatican Radio preserved its independence during the rise of Fascist Italy and Nazi Germany. Following the outbreak of World War II, a week after Pope Pius XII ordered the programming, Vatican Radio broadcast the news that Poles and Jews were being rounded up and forced into ghettos.
Today, programming is produced by over two hundred journalists located in 61 different countries. Vatican Radio produces more than 42,000 hours of simultaneous broadcasting covering international news, religious celebrations, in-depth programs, and music. The current general director is Father Federico Lombardi, S.J.
On 27 June 2015, Pope Francis, in a motu proprio ("on his own initiative") apostolic letter, established the Secretariat for Communications in the Roman Curia, which absorbed Vatican Radio effective 1 January 2017, ending the organization's 85 years of independent operation.Washford transmitting station
Washford transmitting station is a medium wave broadcasting station and low-power digital terrestrial television relay near Washford, Somerset.
It was built in 1933 and uses as antenna a T-antenna between two 152 metres (499 ft) tall guyed masts separated by a distance of 159 metres. Originally the station used cage antennas around each mast. The station uses the frequencies 882 kHz with 100 kW, 1089 kHz with 50 kW and 1215 kHz with 50 kW.
A smaller 45.7 metres (150 ft) mast is used to relay digital terrestrial television services from the Mendip transmitting station. This mast carries the three public service multiplexes at an E.R.P. of 12.4 W.
The front portions of the old transmitter building, are now part of the Tropiquaria wildlife park and house their tropical hall, aquarium, and nocturnal house.
Radio spectrum (ITU)