Crystal Palace transmitting station
From Wikipedia, the free encyclopedia
The Crystal Palace transmitting station is a broadcasting and telecommunications site in the Crystal Palace area of the London Borough of Bromley, England (grid reference TQ339712). Its tower is the second-tallest structure in London. The station is best known as the main television transmitter for the London area.
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[edit] History and development
The station was constructed in the mid-1950s on the site of the old Crystal Palace Aquarium, destroying the majority of it. Its 222 m (728 ft) tower was the tallest structure in London until the construction of the One Canada Square tower at Canary Wharf in 1991. Despite its size, it has been largely overlooked as a London landmark due to its location and simplicity. It has been nicknamed London's Eiffel Tower.
When first constructed it only transmitted BBC Television on the old VHF 405-line system. The Croydon transmitter was then built to broadcast ITV. When UHF transmissions started in 1964 first the new BBC2 and later both ITV and BBC1 were then transmitted from Crystal Palace. However even now Crystal Palace does not transmit analogue Channel 5, this (alone) comes from Croydon about two miles away (although Croydon does have reserve transmitters for ITV and Channel 4, which are only used in the event of a fault or maintenance at Crystal Palace). A couple of years ago the BBC decided that a complete reserve was also a good idea and now all four services are available from Croydon if required. When UK Digital Switch Over is completed in the London area in 2012 all services will come from Crystal Palace again, however because of the site's importance Croydon will be able to be used to duplicate the PBS multiplexes in case of emergency. 405-line VHF television was discontinued in 1985, and now the only television broadcasts from Crystal Palace are on UHF.
The station carries the London regions of BBC One, BBC Two, ITV1 and Channel 4 in analogue, each with an effective radiated power of 1 MW, as well as all six digital terrestrial television multiplexes. These have an ERP of 20 kW, with considerable beam tilt to the south and east. Although DTT requires far less power to achieve the same coverage as analogue TV, this 17 dB difference is too large to ensure comparable coverage. The station therefore has a range of about 30 miles (50 km) for DTT, compared with about 60 miles (90 km) for analogue.
The tower is also used for FM radio transmission of several local radio stations BBC London 94.9, XFM, Choice FM and Virgin Radio, as well as a low powered relay of the 4 BBC national FM services and Classic FM. It also has mediumwave transmitters on 558 kHz (Spectrum Radio), 720 kHz (BBC Radio 4) and 1035 kHz (Kismat Radio). Since the tower is grounded, a wire aerial spun close to it is used for the MW services.
Since 1995, the tower has also been in use as one of five London transmitters for the BBC DAB multiplex. This was joined in 1999 by the Digital One DAB service, and a further local DAB multiplex has also since started transmitting.
In May 2006, Crystal Palace began broadcasting the first terrestrial HDTV signals in the UK. This is to enable a trial group of 450 London homes to test HD broadcasts by the BBC, ITV, Channel 4 and Five, in order to assess the viability and potential problems of future nationwide HD broadcasting.
[edit] Future developments
The UK Government's plans for digital switchover are based on the use of almost all of the UK's current analogue TV transmitter sites. As such, Crystal Palace is expected to remain a key part of the network when the London area is switched over in 2012.
[edit] Channels listed by frequency
- Analogue Radio (AM Medium Wave)
- 558 kHz - Spectrum
- 720 kHz - BBC Radio 4
- 1035 kHz - Kismat Radio
- Analogue Radio (FM VHF)
- 88.8 MHz - BBC Radio 2
- 91.0 MHz - BBC Radio 3
- 93.2 MHz - BBC Radio 4
- 94.9 MHz - BBC London
- 96.9 MHz - Choice FM
- 98.5 MHz - BBC Radio 1
- 100.6 MHz - Classic FM
- 104.9 MHz - XFM
- 105.8 MHz - Virgin Radio
- Digital Radio (DAB)
- Block 11D: 222.064 MHz - Digital One
- Block 12A: 223.936 MHz - Switch London
- Block 12B: 225.648 MHz - BBC
- Analogue Television
- UHF 23 (487.25 MHz) - ITV1 London (Carlton Television/London Weekend Television)
- UHF 26 (511.25 MHz) - BBC One London
- UHF 30 (543.25 MHz) - Channel 4
- UHF 33 (567.25 MHz) - BBC Two
- Digital Television
- UHF 22 (482 MHz) - Multiplex 2 Digital 3 and 4
- UHF 25 (506 MHz) - Multiplex 1 BBC
- UHF 27 (522 MHz) - ITV, Channel 4 and Five HD Trial Multiplex
- UHF 28 (530 MHz) - Multiplex B BBC
- UHF 29 (538 MHz) - Multiplex D National Grid Wireless
- UHF 31 (554 MHz) - BBC HD Trial Multiplex
- UHF 32 (562 MHz) - Multiplex A SDN
- UHF 34 (578 MHz) - Multiplex C National Grid Wireless
[edit] Notes
- Five uses the nearby Croydon Transmitter for its London analogue transmission.
- Two further local DAB multiplexes are also transmitted from the Croydon transmitter.
- Wrotham Transmitter is the main radio transmitter serving London for the 4 BBC national FM services and Classic FM.
- Brookmans Park Transmitter and Droitwich AM transmitter provide the BBC national services to London on medium wave and long wave respectively.
[edit] Trivia
- The Crystal Palace transmitting station can be seen in the film The Italian Job when Charlie (Michael Caine) says the memorable line, "You're only supposed to blow the bloody doors off!", which was filmed in Crystal Palace Park.
[edit] See also
- Tall buildings in London
- National Grid Wireless (which owns the tower)
- Radio masts and towers
- List of Towers
- List of tallest buildings and structures in Great Britain
- List of radio stations
[edit] External links
- The Transmission Gallery: Crystal Palace Transmitter photographs and information
- Pictures and info on Crystal Palace, including co-receivable transmitters
- http://skyscraperpage.com/cities/?buildingID=3886
- Ofcom local transmitter advice
