thebigtower


sandy heath

 

 


THE SANDY HEATH TRANSMITTER is the UHF main station that serves the counties Bedfordshire, Cambridgeshire and Northamptonshire.

This service area represents the western sector of the East Anglia television region, the eastern counties of Suffolk and Norfolk predominantly falling under the respective jurisdiction of the Sudbury and Tacolneston transmitters.  Although Tacolneston is the primary UHF station within the region, Sandy Heath has the greatest population coverage and is also the highest-powered, both historically in respect of analogue transmission and since Digital Switchover.

As well as being the highest-powered transmitter within the region, under analogue it operated at the UK maximum Effective Radiated Power (e.r.p) of 1000kW, matching only the Crystal Palace and Sutton Coldfield transmitters and the Channel 5 transmitters at Croydon and Lichfield.

However, whilst Crystal Palace and Sutton Coldfield will upon Digital Switchover deliver a maximum e.r.p of 200kW (the new UK maximum post-switchover), Sandy Heath now operates at a maximum e.r.p of 180kW and therefore falls slightly short from remaining one of the very-highest powered transmitters.


Aerials (1)>  Aerials (2)>  Site/Stay Images (800x600 or 1024x768)>  Supersize Images>  UHF Map     


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aerials (1)

 

Aerials (2) DSO

 

UHF Coverage Map

 

Site and stay images

 

 

 

 

 

 

 

 

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AERIAL GROUPING

Sandy Heath was originally within Aerial Group A bandwith based on the four main analogue terrestrial services.  However, the addition of Channel 5 on UHF Channel 39 in 1997 followed in 1998 by the original digital multiplex channel allocation forced the station into wideband Group W.  Based on the permanent channels allocated to the post-DSO COM multiplexes, the station will remain within this aerial grouping.


 

 

 

 

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DIGITAL SWITCHOVER (DSO) WORK

Principal re-engineering for Digital Switchover at Sandy Heath has resulted in the replacement of the GRP-cylinder-contained main UHF aerial with a new twelve-tier four-sided multi-panel installation.  Like many other masts, the top engineers platform has been lost as a result of this process.

As for reserve provision, the already substantial pre-DSO digital arrangement has been reconfigured into an installation based around a primary sixteen-tier circulating array.

See Aerials(1) for pre-DSO images and Aerials(2) for post-DSO images and a before and after comparison.

Also, images of the helicopter-assisted aerial replacement operation can be found at mb21 here.

SWITCHOVER COMPLETION

Sandy Heath is the first of the three East Anglia area main UHF transmitters to complete Digital Switchover, the process being implemented as follows -

Stage 1 (DSO1) - 30 March 2011

BBC Two analogue on Channel 27 ceased broadcasting permanently and PSB1 multiplex (BBCA) launched on Channel 27

Stage 2 (DSO2) - 13 April 2011

All other analogue services ceased broadcasting permanently and the remaining PSB/COM digital multiplexes were launched.


Aerials (1)>  Aerials (2)>  Site/Stay Images (800x600 or 1024x768)>  Supersize Images>  UHF Map     


 

 

 

 

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VHF STATION HISTORY

Sandy Heath was originally built as one of two new ITA stations within East Anglia that would initially resolve issues of poor 405-line VHF reception in out-lying parts of the region whilst ultimately providing their respective areas with high-power UHF coverage.

The East Anglia ITV service had been established in October 1959 based on the single high-power VHF Band III transmitter at Mendlesham in Suffolk.  The positioning of this station towards the south-eastern corner of the region had been significantly influenced by the need to minimise power directed towards the eastern coast to avoid interfering with European services.

Whilst this was compensated for by directing high power (200kW) towards the west and north, this still left the fringe areas of Bedfordshire and Lincolnshire with large pockets of inadequate or intereference-prone reception, despite the fact there was very little in terms of propagation-impeding terrain between the 1000-ft high Mendlesham mast and these areas.

As in other similar situations, this became a 'back-burner' issue whilst the ITA concentrated on providing transmitters for areas that were totally unserved.  However, it gained priority with the impending move to UHF as both Bedfordshire and Lincolnshire were identified as areas requiring their own high-power UHF stations.

For the Lincolnshire area, the ITA constructed the Belmont station which would later cause problems with the switch to high-power UHF and ultimately result in the reallocation of the station's ITV transmissions from the Anglia to Yorkshire Television region.

Meanwhile, the site chosen for the Bedfordshire area station was Sandy Heath, which was on an area of public park land and also, like the ITA stations at Black Mountain and Lichfield, close to a quarry.  In a region dominated by low ground, the site offered an above sea level height of 180-ft (55m).  A mast of the fairly typical 750-ft (228m) height was constructed on which a directional VHF Band III aerial was mounted.  This was capable of delivering a maximum vision e.r.p of 30 kW (directed northwards) based on vision and sound transmitters (primary and reserve sets) rated at 500W and 125W respectively.

The VHF service from Sandy Heath began on 13 July 1965, transmitting on VHF Channel 6 using programme feed received directly from Mendlesham.  The areas that benefitted from the improved coverage provided were Bedfordshire, Cambridgshire and Northamptonshire.

UHF TELEVISION HISTORY

The first regular UHF service from Sandy Heath began with BBC2 in the latter half of 1969, completing the principal high-power BBC2 service across East Anglia following the opening of transmitters at Tacolneston and Sudbury in September 1967 and November 1968 respectively.

In accordance with the usual course of events, UHF transmitters for ITV and BBC1 eventually entered service as well, the former starting on 18 January 1971 with the latter commencing on or around the same date.


 

 

 

 

 

Above and left: Station plates on former ITA sites are found only at what are designated as Service Centres.  Sandy Heath slightly falls outside this criteria as it was never a main ITA 405-line station on which the Service Centres are based.

These centres are numbered with the prefix '93' followed by two digits correlating to their current UHF or former VHF tx number e.g 9301 for Croydon, 9302 for Lichfield, 9303 for Winter Hill etc.  Based on this, the logical number for Sandy Heath would be 9324 (from tx number 12400).

 However, as shown on the left it is actually assigned the number 9414 indicating it is classed as a Sub-Service Centre of Mendlesham (Site 9314) and seemingly on this basis qualifies for the station plates.    

 

 

 

 


STATION INFORMATION


Location:

Sandy Heath, Potton, Bedfordshire, SG19 2NH

Grid Reference:

TL204494

Landlord:

Arqiva (Legacy: ITA/IBA/NTL Broadcast)

Ground Height:

55m

BBC1 Region:

BBC East (West opt-out)

Mast Height (+):

228m

ITV1 Region:

Anglia West

Aerial Height (*):

290m

 

UHF Tx Number:

12400

 

 

(+)  Main structure height only - total height including main UHF antenna is 244.9m

 

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

 

 


  CURRENT TRANSMISSIONS

Digital Television 

 

 

 

Analogue Radio (FM)

 

 

 

 

 

 

 

 

 

Service

: Ch/Polarisation/e.r.p

 

 

 Station:

(MHz)

(e.r.p)

PSB1

: 27 / H / 180kW 

 

 

BBC Three Counties Radio:

95.5

1.0kW

PSB2

: 24 / H / 180kW 

 

 

Heart FM (Bedford):

96.9

0.9kW

PSB3

: 21 / H / 180kW 

 

 

 

 

 

COM4

: 51 / H / 170kW 

 

 

Digital Radio

COM5

: 52 / H / 170kW

 

 

 

 

 

COM6

: 48 / H / 170kW

 

 

BBC National (Block 12B)

 

 

 

 

 Digital One (Block 11D)

 

PRE-DIGITAL SWITCHOVER UHF TRANSMISSIONS

(Shutdown completed 13 April 2011)

Analogue Television 

 

 

 

Digital Television

 

 

 

 

 

 

 

 

 

Service

  Ch/Polar/e.r.p

 

 

 

 

Service

 Ch/Polar/e.r.p

BBC1

: 31 / H / 1000kW

 

 

 

 

Mux1

: 42 / H / 20kW

BBC2

: 27 / H / 1000kW  

 

 

 

 

Mux2

: 45 / H / 20kW

ITV1

: 24 / H / 1000kW 

 

 

 

 

MuxA

: 43 / H / 20kW

Ch4

: 21 / H / 1000kW

 

 

 

MuxB

: 67 / H / 20kW

Ch5

: 39 / H / 10kW

 

 

 

 

MuxC

: 40 / H / 20kW

 

  

 

MuxD

: 46 / H / 20kW

 

 

 

 

 

 

 

 

 


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