Crystal Palace transmitting station

Crystal Palace
Height of mast	219 metres (719 ft)[1]
Built	1956
BBC region	BBC London
ITV region	ITV London

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).^[2]

Its tower is the third-tallest structure in London. The station is best known as the main television transmitter for the London area.

History and development

At Night

The station was constructed in the mid-1950s among the ruins of the Crystal Palace. The Aquarium on which it is mostly built was partially destroyed in 1941 during the demolition of the Palace's north water tower.^[3][4] (John Logie Baird's earlier transmitter and TV studios were a separate development at the other end of the Palace and perished with it in 1936.^[5][6])

Its new 219-metre (719 ft)^[1] tower was the tallest structure in London until the construction of One Canada Square at Canary Wharf in 1991. Despite its size, it has been largely overlooked as a London landmark due to its location and simplicity.^{[citation needed]} It has been nicknamed London's Eiffel Tower.

The first transmission from Crystal Palace took place on 28 March 1956, when it succeeded the transmitter at Alexandra Palace where the BBC had started the world's first scheduled television service in September, 1936. In November 1956 the first colour test transmissions began from Crystal Palace relaying live pictures from the studios at Alexandra Palace after BBC TV had closed down for the night. In May 1958 the first experimental Band V 625 line transmissions started from Crystal Palace.

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^{[clarification needed]} 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, but because of the site's importance Croydon will be able to be used to duplicate the PSB 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 Absolute 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 was 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. On 2 December 2009, the site entered service as one of the first DVB-T2 transmitters in the world, carrying a variant of the BBC's Multiplex B broadcasting high-definition TV services.

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. In July 2007 it was confirmed by Ofcom that Crystal Palace would be remaining an A group transmitter after DSO (Digital Switchover).

Channels listed by frequency

Analogue radio (AM medium wave)

Frequency	kW	Service
558 kHz	1	Spectrum
720 kHz	0.75	BBC Radio 4
1035 kHz	2.5	Kismat Radio

These frequencies were used by Lots Road until Tuesday 25 September 2007.

Analogue radio (FM VHF)

Frequency	kW	Service
88.8 MHz	4†	BBC Radio 2
91.0 MHz	4†	BBC Radio 3
93.2 MHz	4†	BBC Radio 4
94.9 MHz	4	BBC London
96.9 MHz	0.03	Choice FM
98.5 MHz	4†	BBC Radio 1
100.6 MHz	2 (V)†	Classic FM
104.9 MHz	2.9	XFM
105.8 MHz	3.73	Absolute Radio

† Relay of Wrotham.

Digital radio (DAB)

Frequency	Block	kW	Operator
222.064 MHz	11D	6.5	Digital One
223.936 MHz	12A	2.1	Switch London
225.648 MHz	12B	10	BBC National DAB

Analogue television

Frequency	UHF	kW	Service
487.25 MHz	23	1000	ITV1
511.25 MHz	26	1000	BBC One
543.25 MHz	30	1000	Channel 4
567.25 MHz	33	1000	BBC Two

BBC Two will shut down on 4 April 2012 and all other services on 18 April 2012.

Digital television Frequency UHF kW Operator 481.8 MHz 22- 20 Digital 3&4 (Mux 2) 505.8 MHz 25- 20 BBC (Mux 1) 529.8 MHz 28- 20 BBC (Mux B) 537.8 MHz 29- 20 Arqiva (Mux D) 554.0 MHz 31 10 BBC B (Mux HD) 561.8 MHz 32- 20 SDN (Mux A) 578.2 MHz 34+ 20 Arqiva (Mux C)

After switchover Frequency UHF kW Operator 482.0 MHz 22 200 Arqiva A 490.0 MHz 23 200 BBC A 506.0 MHz 25 200 SDN 514.0 MHz 26 200 Digital 3&4 530.0 MHz 28 200 Arqiva B 545.8 MHz 30- 200 BBC B

See also

London portal

• Arqiva (which owns the tower)
• List of radio stations in the United Kingdom
• List of tallest buildings and structures in Great Britain
• List of tallest towers in the world
• Radio masts and towers
• Tall buildings in London

References

1. ^ ^{a b} "NGW planning application". Bromley Council planning portal. 2008-04-23. http://212.85.26.243/WAM/pas/externalCasefile.do?councilName=London%20Borough%20of%20Bromley&appNumber=08/01463/FULL1. Retrieved 2008-09-13. 
2. ^ BBC Milestones. Retrieved 13 Oct 2008
3. ^ "War's Worst Raid". TIME. 1941-04-28. http://www.time.com/time/magazine/article/0,9171,765495,00.html. Retrieved 2008-05-29. 
4. ^ Pescod, David FRS (2005-02-10). "Correspondence" (PDF). The Linnean (London: Linnean Society of London) 21 (2): 36. http://www.linnean.org/fileadmin/images/Publications/Linnean-21-2__2__web_complete.pdf. Retrieved 2008-05-29. ^{[dead link]}
5. ^ Glen, Richard E (2003-04-05). "Baird's independent television". Transdiffusion Broadcasting System. http://www.transdiffusion.org/emc/baird/baird_itv.php. Retrieved 2008-05-29. 
6. ^ Herbert, Ray (July 1998). "Crystal Palace Television Studios". Soundscapes (Groningen, The Netherlands: University of Groningen) 1 (4). ISSN 1567-7745. http://www.icce.rug.nl/~soundscapes/VOLUME01/Crystal_Palace.shtml. Retrieved 2008-05-29. 

Bibliography

• R H. Evans, The Crystal Palace FM filler experiment, British Broadcasting Corporation, Division of Engineering, Research and Development Department (1996), ASIN B0018RJ1ZY
• R. W. Burns, British Television: The Formative Years, IET (1986), ISBN 0863410790

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
• Crystal Palace Transmitter at Structurae
• Ofcom local transmitter advice
• Crystal Palace Transmitter at thebigtower.com

Coordinates: 51°25′27″N 0°4′30″W / 51.42417°N 0.075°W / 51.42417; -0.075