thebigtower


dover

 

**ALL PAGES UPDATED JANUARY 2014**


THE DOVER TRANSMITTER is the UHF main station for the far south-east of England, principally serving the Kent area including the majority of the county's coastline, as well as some parts of East Sussex.  It is sited between the villages of West Hougham and Church Hougham, approximately three miles south-west of Dover town centre.

Due to the station positioning near the English Channel, the mast has always carried aerial systems (for both VHF and UHF television) with highly directional properties in order to limit the signal strength towards France for the purpose of avoiding co-channel interference to European stations.

UHF COVERAGE OVERLAP

Dover UHF transmissions directed towards the north-west can be received clearly in some coastal and inland areas of South Essex.  This duplication of coverage is reciprocated by the Sudbury transmitter which is receivable in some parts of the Dover service area, most significantly along the northern coastline of Kent.

Under 405-line VHF, a similar reciprocal overlap existed with the Mendlesham transmitter although by the very nature of VHF coverage the range of these transmissions was significantly more extensive than under UHF.

TRANSMISSION STRUCTURE

Services from Dover are broadcast from a 228.6-metre (750-ft) triangular cross-section lattice stayed-mast.  The fibre-glass cylinder-contained UHF aerial mounted at the top extends the overall height to 243.2 metres (798-ft).  The mast is held in place by fifteen stay lines secured at ground level by nine anchor blocks.

The structure is typical of those on sites originally constructed as main transmitters for the ITV 405-line VHF Band III network. (See STATION HISTORY below).


Aerials>  Site Images (740x400 or 930x560 pixels)>  Supersize Images>  UHF Coverage Map  


 

 

 

 

 

 

 

 

 

 

 

 

400x560 pixel images

 

510x710 pixel images

 

Supersize Images

 


DIGITAL SWITCHOVER

In preparation for Digital Switchover, Dover was subject to many of the re-engineering requirements seen at other stations around the country.  These included mast strengthening in anticipation of the new heavier UHF aerial systems, resulting in the structure being re-stayed with both new lines and new ground anchoring blocks. (See updated Site Images)

The characteristics of the post-switchover UHF aerial system at Dover are however more unique as, like all previous television aerial systems provided for this station, they reflect the need to avoid unwanted coverage towards mainland Europe.

The resultant aerial system comprises a five-sided main UHF antenna which is visibly devoid of UHF panels on the two eastern sides (the coastal direction) and a reserve system which is mounted across the western side of the mast only, the latter in accordance with the earlier installations for digital television.  Images of the new configuration are included under Aerials.

The two stages of the Digital Switchover process took place at Dover as follows -

13 June 2012  - Stage 1 (DSO1)

BBC2 Analogue (Channel 56) closed, Mux 1 closed, BBC1 Analogue temporarily moved to Channel 56 in order to release Channel 50 and PSB1 Multiplex (BBC A) launched on Channel 50.

27 June 2012 - Stage 2 (DSO2)

All remaining analogue services and pre-DSO digital multiplexes ceased and PSB2, PSB3 and COM Multiplexes commenced transmission.


 

 

 

 

 

 

 

 


Aerials>  Site Images (740x400 or 930x560 pixels)>  Supersize Images>  UHF Coverage Map  


STATION HISTORY (VHF)

The Dover station was constructed by the Independent Television Authority (ITA) in order to formally extend coverage of ITV to the south-east of England on the original 405-line VHF Band III system.  Prior to the station opening, the area relied on distant reception from either Croydon, Chillerton Down or Mendlesham.  The regional ITV companies respectively associated with those transmitters sought control of the Dover station, with the ITA eventually awarding the franchise for the area it would serve to Southern Television, making Dover their second transmitter alongside Chillerton Down.

In choosing a site for a station serving the south-eastern extremity of England, the ITA had to address the critical issues of how to avoid (or at least minimise) the risk of interfering with overseas stations, whilst also serving the coastal port towns of Dover and Folkestone which lied in a sudden dip beyond the Dover cliffs.  The obvious solution was to build a station on the Dover cliffs from where the highest-powered transmissions could be beamed in-land, whilst enabling the few outward areas to be served with minimal power directed from the cliff top downwards towards the coast.

To achieve this, engineers undertook the highly complex task of constructing an aerial that took the 'directional-power' principle to a new extreme.  Utilising the 450-ft high site at Church Hougham as a platform, a 750-ft mast was deemed to offer sufficient height for the transmitting aerial, which would be fed by single vision and sound transmitters rated at 4kW and 1kW respectively.

The aerial that was eventually constructed beamed the highest power of 100kW (e.r.p) 50 miles westwards along the southern coastline, allowing a link-up with the service area of Chillerton Down around Eastbourne.  Towards the north, 10kW to 20kW was directed towards areas on the periphery of or beyond coverage from the Croydon transmitter.  Across the eastern and southern arc, transmissions had to be limited to just 1kW, providing just enough power to serve Dover and Folkestone.  After a prolonged period of helicopter-based testing, the aerial was deemed to be performing as anticipated.

Dover went into full programme service on 31 January 1960, broadcasting on VHF Channel 10.

STATION HISTORY (UHF)

Having begun its first regular UHF transmissions with BBC2 from 11 February 1967, Dover was in the second group of transmitters to begin broadcasting ITV and BBC1 in UHF-Colour, respectively from 13 December 1969 and 3 January 1970.

Dover was also the base for one of the fourteen nationwide ITA Colour Control Rooms (CCRs), in this instance covering all ITA UHF and VHF transmitters within the area of Kent served by Southern Television plus all of East Sussex.  With a CCR also based at Chillerton Down, this was the only ITV franchise area to feature two control rooms, although both were absorbed in 1978 by the Regional Operation Centre (ROC) at Croydon.

Typically for a transmitter upgrading from VHF to UHF, the transmission range of Dover was significantly reduced under the latter. Consequently, a further UHF main station was opened at Bluebell Hill, near Maidstone, on 25 February 1974 in order to serve the area of North Kent that was beyond the UHF range of Dover and also that of the Crystal Palace transmitter.

ANALOGUE UHF CHANNELS

In common with most of the UHF main stations located near the south-coast of England, Dover was required to deviate from using one of the standard four-channel sets as none of these could be accommodated without causing interference issues in mainland Europe.

Three of the chosen channels for Dover (50, 56 and 66) were notable for reasons as follows -

Channel 50 (BBC1) - The only use at a UHF main station within a C/D aerial group range

Channel 56 (BBC2) - The only use at all at a UHF main station (not including Channel 5)

Channel 66 (ITV)   -  One of only two such uses at a UHF main station - the other being Hannington).

Other south-coast area stations that deviated from the standard channel groupings (in addition to Hannington) were Bluebell Hill, Heathfield and Midhurst.


 

 

 

 

 

 

 

 

 

 

 

 

Site Images  740x400 or 930x560 pixels

 

Aerials

 

UHF Coverage Map

 


STATION INFORMATION


Location:

Hougham Court Lane, Church Hougham, CT15 7AF

Grid Reference:

TR274397

Landlord:

Arqiva (Legacy: ITA/IBA/NTL Broadcast)

Ground Height:

135m

BBC1 Region:

South East

Mast Height ("):

228.6m

ITV1 Region:

Meridian East

Aerial Height (*):

366m

 

UHF Tx Number:

11300

(") Main structure height only - UHF antenna inclusive is 243.2m 

 

(*) UHF aerial height above sea level (a.o.d)

 

 


 CURRENT TRANSMISSIONS

Digital Television 

 

 

 

Analogue Radio (FM)

 

 

 

 

 

 

 

 

 

Service

: Ch/Polarisation/e.r.p

 

 

 Service:

(MHz)

(e.r.p)

PSB1

: 50 / H / 80kW  

 

 

Classic FM (H):

101.8

1.0kW

PSB2

: 51 / H / 80kW 

 

 

Classis FM (V):

101.8

4.2kW

PSB3

: 53 / H / 80kW  

 

 Heart FM (Kent):

97.0

0.5kW

COM4

: 55 / H / 40kW  

 

   

COM5

: 59 / H / 40kW 

 

 

COM6

: 48 / H / 40kW 

Digital Radio (DAB)

 

 

 

 

 

 

 

 

 

 

 

 

BBC National (Block 12B)

 

 

 

 

 

Digital One (Block 11D)

 

 

 

 

 

 

PRE-DIGITAL SWITCHOVER UHF TRANSMISSIONS

(Shutdown completed 27 June 2012)

Analogue Television 

 

 

 

Digital Television

 

 

 

 

 

 

 

 

 

Service

  Ch/Polar/e.r.p

 

 

 

 

Service

 Ch/Polar/e.r.p

BBC1

: 50 / H / 100kW

 

 

 

 

Mux1

: 68 / H / 1.0kW

BBC2

: 56 / H / 100kW  

 

 

 (+)

 

Mux1

: 45 / H / 2.0kW

ITV1

: 66 / H / 100kW 

 

 

 

 

Mux2

: 61 / H / 2.0kW

Ch4

: 53 / H / 100kW

 

 

 (+)

 

Mux2

: 42 / H / 2.0kW

Ch5

: No Service

 

 

 

 

MuxA

: 60 / H / 2.0kW

 

 

 

 

 

 

 

MuxB

: 58 / H / 2.0kW

 

 

 

 

 

 

 

MuxC

: 62 / H / 1.0kW

 

 

 

 

 

(+)

 

MuxC

: 39 / H / 1.0kW

 

 

 

 

 

MuxD

: 55 / H / 2.0kW

 

 

 

 

(+) = Dover 'B'

 

 

 


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