thebigtower


strabane

 


THE STRABANE TRANSMITTING STATION provides UHF Television and Digital (DAB) Radio services to the Strabane area of County Tyrone, Northern Ireland.

Its history lies in the ITV 405-line VHF Television network when it served a large area of West Ulster, operating as a dependent relay of the Black Mountain transmitter near Belfast, distinguished by the fact it was the only ITV VHF relay to have the same power capability as its parent station.  It has provided UHF Television coverage since 1977 as a relay of the Limavady main station, albeit at much lower power and reduced service area than its equivalent VHF Television coverage.

TRANSMISSION STRUCTURE  

The other distinguishing characteristics of the Strabane station lay in the transmission mast which stands at a height of 305.5 metres (1002-ft) making it the tallest structure in the whole of Ireland.

It is one of seven triangular cross-section lattice stayed structures based around a height of 305 metres (1000-ft) that were constructed by the Independent Television Authority (ITA), with the other structures sited at Arfon, Black Hill, Caldbeck, Durris, Lichfield and Mendlesham.

It is with the Arfon station in North Wales that Strabane has most in common with both being the site of the tallest structures in their respective countries whilst also having only ever served as relay stations for the purpose of both UHF and VHF Television.

DIGITAL SWITCHOVER

As with all transmitters in Northern Ireland, Strabane completed Digital Switchover during the night of 23/24 October 2012. Thereafter it transmitted digital television for the first time having not been included in the pre-switchover digital network.

As it is not one of the primary relay stations, transmissions are confined to the three Public Service Broadcast (PSB) multiplexes with the station remaining within Group B aerial bandwidth.


 

 

 

 

 

 

 

 

 

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Aerials>  Site/Stay Images (740x430 or 930x550)>  Supersize Images>  405-line Map


STATION HISTORY (VHF TELEVISION)

The Strabane transmitter was built by the Independent Television Authority (ITA) to overcome the problem of providing Independent Television (ITV) coverage on 405-line VHF Band III to the western counties of Northern Ireland.

Coverage of Northern Ireland by ITV was inaugurated on 31 October 1959 from the Black Mountain transmitter, sited on the high ground of West Belfast near the BBC Band I transmitter at Divis.  From this site, ITV was easily receivable across the counties of Armagh, Antrim and Down and some eastern parts of Londonderry and Tyrone.

However, the abilities of Black Mountain to serve West Ulster were restricted, not least by a height limit of 750-ft being placed upon the mast, a higher structure being refused permission due to airport proximity.   

The Independent Television Authority (ITA) decided the problem could be resolved by means of a single relay station near the centre of the target area, subject to a high aerial elevation being achieved.  A suitable site grounded at 900-ft (274m) above sea level was obtained five miles south-east of the town of Strabane.

With the need to mount the transmitting aerial at more than double the ground height, a 1000-ft (305m) mast was required.

Structures of this height had been the preserve of main stations, the first of which opened at Mendlesham in 1959, although the ITA had by 1962 extended the privilege to the relay station at Arfon in North Wales.  Furthermore, the expenditure this would incur at Strabane could be justified on the grounds that it provided a one-site solution and also the fact the station would be capable of delivering a maximum Effective Radiated Power (e.r.p) of 100 kilowatts, making it the highest-powered Band III relay in the United Kingdom.  At this power, it also matched the output of Black Mountain, such a relationship between relay and parent also being unique within the ITV Band III transmitter network.

The actual e.r.p transmitted was dictated by the directional properties of the transmitting aerial which was designed to limit the intrusion into the area of the Irish Republic lying to the west.  Accordingly, the aerial beamed a 90kW (e.r.p) signal towards the north (covering Londonderry) and south (covering the west of Tyrone and all of County Fermanagh), whilst just 10kW was directed west (to the border with the Irish Republic) and east (across the remaining ground not served by Black Mountain). These values were achieved from single vision and sound transmitters, rated at actual powers of 4kW and 1kW respectively.

Strabane entered full programme service on 18 February 1963, transmitting on VHF Channel 8.  The service continued until the closure of transmissions on 405-line VHF across the United Kingdom in January 1985.

STATION HISTORY (UHF TELEVISION)

From 15 July 1977, Strabane was added to the expanding network of UHF-colour transmitters, with the objective of improving UHF coverage in the immediate vicinity.  The principal UHF service to the Londonderry area commenced in December 1975 from the Limavady UHF main station, supported by a relay station in Londonderry itself.

The Strabane station was designated the second UHF relay of Limavady, with the relatively modest output of 2kW (e.r.p) from the aerial mounted at the top of the mast being sufficient to achieve the desired coverage improvement.


 

 

 

 

 

 

 

 

 

 

 

 

Aerials

 

Site/Stay Images (740x430 or 930x550 pixels)

 

405-line Map

 

 

 

 

 

 

 

 


  STATION INFORMATION


Location:

Ligford Road, Strabane, County Tyrone

Grid Reference:

IH393947

Landlord:

Arqiva (Legacy: ITA/IBA/NTL Broadcast)

Ground Height:

274m

BBC Region:

Northern Ireland

Mast Height ("):

305.5m

ITV Region:

UTV

Aerial Height (*):

585m

 

UHF Tx Number:

13004

(") Main structure height excluding UHF antenna

 

 

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

 

 


  CURRENT TRANSMISSIONS

Digital Television

 

 

Analogue Radio (FM)

 

 

 

 

 

 

 

 

 

Service

: Ch/Polarisation/e.r.p

 

 

 No Services

PSB1

: 45 / V / 0.4kW 

 

 

 

 

 

PSB2

: 42 / V / 0.4kW 

 

 

 

 

 

PSB3

: 39 / V / 0.4kW

 

 

 Digital Radio

COM4

: No service

 

 

 

COM5

: No service  

 

 

BBC National (Block 12B)

COM6

: No service

 

 

Bauer Northern Ireland (Block 12D)

 

 

 

 

 

PRE-DIGITAL SWITCHOVER UHF TRANSMISSIONS

(Shutdown completed 24 October 2012)

Analogue Television 

 

 

 

Digital Television

 

 

 

 

 

 

 

 

 

Service

  Ch/Polar/e.r.p

 

 

 

 

 

 Ch/Polar/e.r.p

BBC1

: 39 / V / 2kW

 

 

 

 

 

 

BBC2

: 45 / V / 2kW  

 

 

 

 

No pre-DSO service

ITV1

: 49 / V / 2kW

 

 

 

 

 

 

Ch4

: 42 / V / 2kW

 

 

 

 

 

 

Ch5

: No Service

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Black Mountain    Divis     Arfon

 

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