Location | Hertfordshire |
---|---|
Mast height | 71.3 metres (234 ft) [1] |
Coordinates | 51°39′55.8″N0°14′31.2″W / 51.665500°N 0.242000°W |
Grid reference | TQ216977 |
Built | March 1975 [1] |
Saffron Green transmitting station is a facility for medium wave broadcasting near Saffron Green Meadows in Hertfordshire, 19km north-west of London. [2] It was built by the Independent Broadcasting Authority in March 1975 to transmit two Independent Local Radio stations - Capital Radio and LBC. An earlier medium wave transmitting station is Brookmans Park, also in Hertfordshire and built by the BBC in the 1920s. The last station broadcasting from this site stopped in October 2024 and the future of the site is unknown. [3]
Until the 1970s the BBC had a monopoly on radio broadcasting in the UK, with the exception of pirate stations and Radio Luxembourg. This changed in 1972 with the Sound Broadcasting Act [4] and the IBA let two contracts for commercial radio in London, one for "news and information" and one for "general and entertainment". [5] The news and information contract went to London Broadcasting Company (LBC) which started broadcasting on 8 October 1973; [6] [7] the entertainment contract was won by Capital Radio which started broadcasting on 16 October 1973. [8]
All ILR stations were allocated an FM frequency and a MW frequency which had to broadcast the same material. Both stations launched using temporary MW transmitters and a T-antenna strung between the chimneys at Lots Road, a power station in Chelsea used by London Underground. [9] The IBA struggled to get planning permission for the permanent station but after appealing, planning permission was granted in 1972, allowing the station to open in 1975. [10] [11]
The station was designed to operate without staffing and monitoring of the output was done by the radio station, error codes were transmitted on a 4.7 kHz subcarrier which were picked up by remote monitoring but were too quiet to be audible. There were two input feeds - one was a single Tariff M music circuit from the studio, and provided by the Post Office. The back up was the feed from the FM transmitter. [12]
The MW frequencies allocated to the two stations were 1546 kHz and 1151 kHz, shared with other stations in the UK. In order to avoid interference the new station needed to use a tower array directional antenna so that the broadcasts were focused on London rather than interfering with other transmissions such as 1546 kHz in Bristol and 1151 kHz in Birmingham. [13]
Saffron Green has a line of four mast radiators 71 m tall and 61 m apart at an angle of 161° ETN . Buried 30–45 cm underneath each mast there is an earth mat of copper wire. [2] The site had seven Marconi B6029 transmitters running at a power of 10 kW, 5 main and 2 standby. [12]
On 1 July 1985 there was a fire in the LBC reserve transmitter which took out both services over night. Services were restored next day, although the reserve transmitter needed to be replaced. [14] [15] In September 2020 one of the masts in the array was struck by lightning which damaged the antenna tuning unit. Since then the reserve antenna, a wire from one of the masts, has been in use instead. [1]
In 1987 the IBA required stations to stop simulcasting on AM and FM and to provide different services. Capital radio split into Capital FM and Capital Gold, an oldies station. In 2007 Capital Gold was merged with Classic Gold to produce Gold, a similar oldies station. Gold stopped broadcasting on MW in London on 29 September 2023, as part of a move by owners Global to stop using medium wave. It remains on DAB. [16]
LBC has a complicated history of takeovers and renames. It remained broadcasting on medium wave until 30 October 2024. It remains on DAB. [3]
Frequency | Power | Service |
---|---|---|
1151 kHz until Nov 1978 1152 kHz [2] | 5.5kW transmitter power [2] 23.5kW maximum EMRP [15] | LBC (1975–1989) London Talkback Radio (1989–1994) |
1546 kHz until Nov 1978 1548 kHz [2] | 27.5kW transmitter power [2] 97.5kW maximum EMRP [15] | Capital Radio (1975–1988) Capital Gold (1988–2007) |
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.
Low frequency (LF) is the ITU designation for radio frequencies (RF) in the range of 30–300 kHz. Since its wavelengths range from 10–1 km, respectively, it is also known as the kilometre band or kilometre waves.
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 hectometers. Frequencies immediately below MF are denoted as 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.
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'.
Capital London is an Independent Local Radio station owned and operated by Global Media & Entertainment as part of its national Capital Network.
Independent Local Radio is the collective name given to commercial radio stations in the United Kingdom.
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LBC News is a British digital radio station owned and operated by Global. The sister station of LBC, it broadcasts rolling news 24 hours a day nationwide on DAB and Global Player. The station used to broadcast on analogue radio in Greater London on 1152 AM until Wednesday 30 October 2024.
Lots Road Power Station is a disused gas- and oil-fired power station on the River Thames at Lots Road in Chelsea, London in the south-west of the Royal Borough of Kensington & Chelsea, which supplied electricity to the London Underground system. It is sometimes erroneously referred to as Fulham Power Station, a name properly applied to another former station a mile south-west along the Tideway.
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The Transmitter Ismaning was a large radio transmitting station near Ismaning, Bavaria, Germany. It was inaugurated in 1932. From 1932 to 1934 this transmitter used a T-antenna as transmitting antenna, which was spun between two 115-metre-high free-standing wooden lattice towers, which were 240 metres apart. As this antenna had an unfavourable vertical radiation pattern, which produced much skywave resulting in a too small fading-free reception area at night, in 1934 a new antenna was installed. Therefore, one of the towers was dismantled and rebuilt on a 39-metre-high (128 ft) wooden lattice base. While this work took place, an L-Antenna was used, which was spun between the other tower and a small auxiliary wooden tower. It became defunct in 1977 and was destroyed in 1983.
The Winter Hill transmitting station is a broadcasting and telecommunications site on Winter Hill, at the south eastern boundary of the Borough of Chorley, Lancashire, England, and above Bolton. It is owned and operated by Arqiva.
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The Brookmans Park transmitting station is a facility for medium wave (MW) broadcasting at Brookmans Park, Hertfordshire, north of London. The station was built in the 1920s by the BBC as the first of a network of regional dual transmitter stations, replacing the city-based ones used previously, and this was to cover the Home Counties, London and South East. The station is now owned by Arqiva and transmits BBC Radio 5 Live, talkSPORT, Absolute Radio and Lyca Radio. Other medium wave broadcasts for London come from the Saffron Green transmitting station, built by the Independent Broadcasting Authority and also in Hertfordshire.
The Ashton Moss transmitting stations are two independent facilities for medium wave broadcasting near Ashton Moss, an area of Tameside in Greater Manchester. They are approximately 3⁄4 mile (1.2 km) apart.
The Grigoriopol transmitter, officially the Transnistrian Radio and Television Center, is a very large broadcasting facility situated near Maiac, an urban settlement 11 km northeast of Grigoriopol, Transnistria (Moldova).
This is a list of events in British radio during 1990.
This is a list of events in British radio during 1988.
This is a list of events in British radio during 1973.
This is a timeline of the development of radio in London.