Mendip TV Mast - AbsoluteAstronomy.com

The Mendip transmitting station is a broadcasting

Broadcasting

Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

and telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

s facility, situated on the summit of Pen Hill

Pen Hill

Pen Hill forms part of the Mendip Hills plateau in Somerset, England. The hill is located in St Cuthbert Out civil parish in Mendip district.The name Pen is believed to be Celtic for hill or tor....

, part of the Mendip Hills

Mendip Hills

The Mendip Hills is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running east to west between Weston-super-Mare and Frome, the hills overlook the Somerset Levels to the south and the Avon Valley to the north...

range in Somerset

Somerset

The ceremonial and non-metropolitan county of Somerset in South West England borders Bristol and Gloucestershire to the north, Wiltshire to the east, Dorset to the south-east, and Devon to the south-west. It is partly bounded to the north and west by the Bristol Channel and the estuary of the...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, at 305 metres (1,001 ft) above sea level. The station is located in St Cuthbert Out

St Cuthbert Out

St Cuthbert Out, sometimes Wells St Cuthbert Out is a civil parish in the Mendip district of Somerset, England. It entirely surrounds the city and parish of Wells. According to the 2001 census it had a population of 3,459. The parish is crossed by the Monarch's Way long distance footpath.The...

civil parish in Mendip

Mendip

Mendip is a local government district of Somerset in England. The Mendip district covers a largely rural area of ranging from the Mendip Hills through on to the Somerset Levels. It has a population of approximately 110,000...

district. It includes a 281.6 metres (924 ft) tall mast, which was built in 1967 and weighs around 500 tonnes, and is the tallest structure in the southwestern England. The mast currently broadcasts digital television, FM analogue radio and DAB digital radio, and had broadcast analogue colour television from 1967 until 2010.

Until 2008 a GRP

Glass-reinforced plastic

Fiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....

aerial cylinder, which contains the analogue television transmitting antennas, was located at the top of the mast, bringing the total height of the structure to 305 metres (1,001 ft). With a mean height of 596 metres (1,955 ft) above sea level, the analogue television antennas were amongst the highest in the UK. The analogue television antennas were removed in 2010, the original antenna cylinder being replaced with a new antenna assembly, ready for digital switchover in 2010. The new assembly is slightly shorter than the previous cylinder causing the overall mast height to be reduced from 305 metres (1,001 ft) to 293 metres (961 ft).

There are around twelve red aircraft warning lamps (six sets of two lights) up the mast with two lights on top. The lights were upgraded in February 2007 to comply with CAA

United Kingdom Civil Aviation Authority

The Civil Aviation Authority is the public corporation which oversees and regulates all aspects of aviation in the United Kingdom. The CAA head office is located in the CAA House on Kingsway in Holborn, London Borough of Camden...

2000 Air Navigation Order, designed to prevent low flying aircraft from hitting the mast in adverse weather conditions.

The station is owned and operated by Arqiva

Arqiva

Arqiva is a telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Republic of Ireland. The present company, with headquarters located at Crawley Court in the village of Crawley, Hampshire, was formed by National Grid Wireless...

(which acquired the National Grid Wireless, previously Crown Castle.)

The mast was entirely repainted during 2007.

The mast has become a well known and loved Mendip landmark and can provide some spectacular images when engulfed in fog or cloud or illuminated in full sunlight. It also provides a unique method of identifying the hills from a distance.

Television

Mendip was set up as a C/D group transmitter when it entered service with analogue PAL transmissions. In July 2007, Ofcom

Ofcom

Ofcom is the government-approved regulatory authority for the broadcasting and telecommunications industries in the United Kingdom. Ofcom was initially established by the Office of Communications Act 2002. It received its full authority from the Communications Act 2003...

confirmed that it would remain a C/D group transmitter at digital switchover. The mast broadcasts digital television over a large area of the west of England, including Somerset

Somerset

, Wiltshire

Wiltshire

Wiltshire is a ceremonial county in South West England. It is landlocked and borders the counties of Dorset, Somerset, Hampshire, Gloucestershire, Oxfordshire and Berkshire. It contains the unitary authority of Swindon and covers...

, North Somerset

North Somerset

North Somerset is a unitary authority in England. Its area covers part of the ceremonial county of Somerset but it is administered independently of the non-metropolitan county. Its administrative headquarters is in the town hall in Weston-super-Mare....

, Bath and North-East Somerset, Bristol

Bristol

Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

, South Gloucestershire

South Gloucestershire

South Gloucestershire is a unitary district in the ceremonial county of Gloucestershire, in South West England.-History:The district was created in 1996, when the county of Avon was abolished, by the merger of former area of the districts of Kingswood and Northavon...

and Southern Gloucestershire

Gloucestershire

Gloucestershire is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn, and the entire Forest of Dean....

. The station also covers the coastal areas of south east Wales

Wales

Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

, and in the days of analogue TV, many households used it in preference to their more local station, Wenvoe. This is because prior to the digital switchover, Mendip carried Channel 4

Channel 4

Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...

and Channel 5, whereas Wenvoe only carried S4C

S4C

S4C , currently branded as S4/C, is a Welsh television channel broadcast from the capital, Cardiff. The first television channel to be aimed specifically at a Welsh-speaking audience, it is the fifth oldest British television channel .The channel - initially broadcast on...

, which broadcast a lot of Welsh language programming. Indeed many houses still have aerials directed at both stations. Power on analogue transmissions was 500 kW (erp) on channels 1 to 4 but only 126 kW on Channel 5. The latter was transmitted outside of the original C/D grouping of the transmitter but most people in reasonable signal areas could receive it anyway, see aerial gain curves. All 6 digital multiplexes were transmitted at 10 kW until switchover in 2010 when the power on the "BBC A", "BBC B/HD" and "D3&4" multiplexes was boosted to 100 kW. In 2011, SDN was boosted to 50 kW and in 2012 the remaining two Arqiva multiplexes will be boosted to 50 kW too. Mendip's population coverage is around 1.5 million, although some homes in the immediate vicinity, such as those in Cheddar

Cheddar

Cheddar is a large village and civil parish in the Sedgemoor district of the English county of Somerset. It is situated on the southern edge of the Mendip Hills, north-west of Wells. The civil parish includes the hamlets of Nyland and Bradley Cross...

are unable to receive a signal due to being in the shadow of the Mendip Hills and therefore have to depend on local relays.

Radio

Mendip broadcasts FM

FM broadcasting

FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting"...

(analogue VHF) radio for BBC Somerset and the Severn Estuary Regional service of Galaxy 101 (now known as Kiss 101

Kiss 101

Kiss 101 was a radio station in Bristol broadcasting out to South Wales and South West England playing Hip Hop, dance music and R&B. It now forms part of a national Kiss station, which also includes Kiss 105-108 and Kiss 100 and is owned by Bauer Radio.-History:The station originally started...

). It transmits high power Digital Audio Broadcasting

Digital audio broadcasting

Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....

(DAB) signals for Digital One

Digital One

Digital One is a national commercial digital radio multiplex in the United Kingdom, owned by Arqiva. , the multiplex covers more than 90% of the populationfrom a total of 137 transmitters...

and BBC National DAB multiplexes, as well as a lower power local service to Glastonbury for MXR Severn Estuary

MXR Severn Estuary

MXR Severn Estuary is a regional commercial digital radio multiplex in the United Kingdom, which serves the West of England and South Wales, including Bristol, Bath, Weston-super-Mare, Cardiff, Newport, Swansea, the South Wales Valleys and north Somerset....

. These three multiplexes carry approximately ten digital radio stations each. An additional DAB multiplex, MuxCo Somerset

MuxCo Somerset

MuxCo , is the name of the Digital Audio Broadcasting multiplex operator for the county of Somerset, England.It is a consortium made up of three companies - UKRD, the Local Radio Company and National Grid Wireless all owning a third share...

, was awarded a licence in 2008 to broadcast local and national services to Somerset. As of 2010, it is expected that MuxCo Somerset will use the Mendip station, though transmissions have yet to commence.

Analogue

Frequency	kW	Service
95.5 MHz	5	BBC Somerset
101.0 MHz	40	Kiss 101 Kiss 101 Kiss 101 was a radio station in Bristol broadcasting out to South Wales and South West England playing Hip Hop, dance music and R&B. It now forms part of a national Kiss station, which also includes Kiss 105-108 and Kiss 100 and is owned by Bauer Radio.-History:The station originally started...

Digital

Frequency	Block	kW	Operator
222.064 MHz	11D	5	Digital One Digital One Digital One is a national commercial digital radio multiplex in the United Kingdom, owned by Arqiva. , the multiplex covers more than 90% of the populationfrom a total of 137 transmitters...
225.648 MHz	12B	5	BBC National DAB
227.360 MHz	12C	0.75	MXR Severn Estuary MXR Severn Estuary MXR Severn Estuary is a regional commercial digital radio multiplex in the United Kingdom, which serves the West of England and South Wales, including Bristol, Bath, Weston-super-Mare, Cardiff, Newport, Swansea, the South Wales Valleys and north Somerset....

Analogue

Mendip radiated all 5 analogue services until the digital switchover between 24 March - 7 April 2010.

Frequency	UHF	kW	Service
599.25 MHz	37	126	Channel 5
735.25 MHz	54	500	Channel 4 Channel 4 Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...
767.25 MHz	58	500	BBC One BBC One BBC One is the flagship television channel of the British Broadcasting Corporation in the United Kingdom. It was launched on 2 November 1936 as the BBC Television Service, and was the world's first regular television service with a high level of image resolution...
791.25 MHz	61	500	ITV1 ITV1 ITV1 is a generic brand that is used by twelve franchises of the British ITV Network in the English regions, Wales, southern Scotland , the Isle of Man and the Bailiwicks of Jersey and Guernsey. The ITV1 brand was introduced by Carlton and Granada in 2001, alongside the regional identities of their...
815.25 MHz	64	500	BBC Two BBC Two BBC Two is the second television channel operated by the British Broadcasting Corporation in the United Kingdom. It covers a wide range of subject matter, but tending towards more 'highbrow' programmes than the more mainstream and popular BBC One. Like the BBC's other domestic TV and radio...

On 24 March 2010 BBC Two was switched off on UHF 64 and ITV1 was switched from UHF 61 for its final weeks of service. UHF 61 was then used to carry the digital BBC A multiplex at full power (100 kW), the first digital multiplex to reach full power from the site.

Frequency	UHF	kW	Service
599.25 MHz	37	126	Channel 5
735.25 MHz	54	500	Channel 4 Channel 4 Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...
767.25 MHz	58	500	BBC One BBC One BBC One is the flagship television channel of the British Broadcasting Corporation in the United Kingdom. It was launched on 2 November 1936 as the BBC Television Service, and was the world's first regular television service with a high level of image resolution...
815.25 MHz	64	500	ITV1 ITV1 ITV1 is a generic brand that is used by twelve franchises of the British ITV Network in the English regions, Wales, southern Scotland , the Isle of Man and the Bailiwicks of Jersey and Guernsey. The ITV1 brand was introduced by Carlton and Granada in 2001, alongside the regional identities of their...

Digital switchover was completed on 7 April 2010. All analogue TV was discontinued permanently from this date. See below for the initial configuration of the digital TV transmissions.

Digital

Digital terrestrial television was first transmitted from the Mendip mast from 15 November 1998 using the frequency gaps between the analogue TV broadcasts. In order to limit possible interference to the analogue transmissions, power output on the digital multiplexes was comparatively very low. Until the start of the Digital Switchover process on 28 March 2010 the frequencies were:

Frequency	UHF	kW	Operator
746.2 MHz	55+	10	Digital 3&4 Digital 3&4 Digital 3&4 is a consortium consisting of regional Channel 3 companies and Channel 4 Television Corporation, which operates a multiplex broadcasting from a number of transmitter sites in the UK, carrying television and radio channels from both ITV and Channel 4; however three per-cent of the... (Mux 2)
754.2 MHz	56+	10	Arqiva Arqiva Arqiva is a telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Republic of Ireland. The present company, with headquarters located at Crawley Court in the village of Crawley, Hampshire, was formed by National Grid Wireless... (Mux C)
778.2 MHz	59+	10	BBC BBC The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff... (Mux 1)
802.2 MHz	62+	10	SDN S4C Digital Networks SDN is a company that operates Multiplex A, one of the six groups of channels on digital terrestrial television in the United Kingdom... (Mux A)
826.2 MHz	65+	10	BBC (Mux B)
842.0 MHz	67	10	Arqiva (Mux D)

On 28 March 2010, Multiplex 1 on UHF 59+ was closed and replaced by BBC A on UHF 61 (which had just been vacated by analogue ITV1).
BBC A was transmitted at full power (100kW) and in 64QAM, 8k carriers mode from the start. Until 7 April 2010, the frequency allocation was now:

Frequency	UHF	kW	Operator
746.2 MHz	55+	10	Digital 3&4 Digital 3&4 Digital 3&4 is a consortium consisting of regional Channel 3 companies and Channel 4 Television Corporation, which operates a multiplex broadcasting from a number of transmitter sites in the UK, carrying television and radio channels from both ITV and Channel 4; however three per-cent of the... (Mux 2)
754.2 MHz	56+	10	Arqiva Arqiva Arqiva is a telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Republic of Ireland. The present company, with headquarters located at Crawley Court in the village of Crawley, Hampshire, was formed by National Grid Wireless... (Mux C)
794.0 MHz	61	100	BBC BBC The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff... A
802.2 MHz	62+	10	SDN S4C Digital Networks SDN is a company that operates Multiplex A, one of the six groups of channels on digital terrestrial television in the United Kingdom... (Mux A)
826.2 MHz	65+	10	BBC (Mux B)
842.0 MHz	67	10	Arqiva (Mux D)

Following the completion of analogue TV shutdown on 7 April 2010, Mendip transmitted all of its higher powered multiplexes at 100 kW.
From this date until the second-stage switchover of 27 September 2011 the frequency allocation was:

Frequency	UHF	kW	Operator
738.0 MHz	54	100	Digital 3&4 Digital 3&4 Digital 3&4 is a consortium consisting of regional Channel 3 companies and Channel 4 Television Corporation, which operates a multiplex broadcasting from a number of transmitter sites in the UK, carrying television and radio channels from both ITV and Channel 4; however three per-cent of the...
754.2 MHz	56+	10	Arqiva Arqiva Arqiva is a telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Republic of Ireland. The present company, with headquarters located at Crawley Court in the village of Crawley, Hampshire, was formed by National Grid Wireless... A
770.0 MHz	58	100	BBC BBC The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff... B
794.0 MHz	61	100	BBC A
802.2 MHz	62+	10	SDN S4C Digital Networks SDN is a company that operates Multiplex A, one of the six groups of channels on digital terrestrial television in the United Kingdom...
842.0 MHz	67	26	Arqiva B

With the completion of digital switchover at Oxford, all multiplexes could be moved to their final channel allocations with the exception of Arqiva A. SDN increased to full power output.
From 28 September 2011 to 28 March 2012 the current frequency allocation is:

Frequency	UHF	kW	Operator
690.0 MHz	48	50	SDN S4C Digital Networks SDN is a company that operates Multiplex A, one of the six groups of channels on digital terrestrial television in the United Kingdom...
722.0 MHz	52	26†	Arqiva Arqiva Arqiva is a telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Republic of Ireland. The present company, with headquarters located at Crawley Court in the village of Crawley, Hampshire, was formed by National Grid Wireless... B
738.0 MHz	54	100	Digital 3&4 Digital 3&4 Digital 3&4 is a consortium consisting of regional Channel 3 companies and Channel 4 Television Corporation, which operates a multiplex broadcasting from a number of transmitter sites in the UK, carrying television and radio channels from both ITV and Channel 4; however three per-cent of the...
770.0 MHz	58	100	BBC BBC The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff... B
794.0 MHz	61	100	BBC A
842.0 MHz	67††	12.5†	Arqiva A

† Power level expected to be increased to 50kW in March 2012 after completion of digital switchover at Salisbury.

†† Temporary parking channel. Final channel TBC, awaiting completion of digital switchover at Salisbury.

External links

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Television

Radio

Analogue

Digital

Analogue

Digital

See also

External links