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5.1 Detailed Coverage Measurements

Weymouth town centre is well served by the WeymouthTV relay station where the field strength in many places is in excess of 80 dBµV/m. The field strength from the Stockland Hill main TV station is much lower at around 60 dBµV/m. However the vast majority of roof-top aerials are ‘Contract’ and many are poor quality installations. Digital Terrestrial Television is not available at the locations we visited. 90% of aerials are directed towards Weymouth and 10% towards Stockland Hill, (probably for a historical reason because the Weymouth relay station was built later).
Recommendation: viewers with problems should move from Stockland Hill to Weymouth.  ‘Contract’ aerials should be replaced with new ‘digital ready’ aerial installations.

In Chickerell, 3 km west of Weymouth town centre, ITU-R grade 5 reception  is possible from Weymouth and Stockland Hill. Digital Terrestrial Television (DTT) reception is available on some multiplexes from Stockland Hill. The vast majority of roof-top aerials are ‘Contract’ and appear to have been in place for a number of years.
Recommendation: ‘Contract’ aerials should be replaced with new ‘digital ready’ aerial installations
Broadwey is 3 km north of Weymouth town centre. In this area, ITU-R grade 5 reception is possible from Weymouth and Stockland Hill where field strengths are in the region of 90 dBµV/m and 70 dBµV/m respectively. About 95% of aerials are directed towards Weymouth. Digital Terrestrial Television is not available in this area. The majority of aerials are ‘Contract’ aerials and appear in our estimation have been in place many years.
Recommendation: replace ‘Contract aerials’ with new digital ready aerial installations and possibly move to Weymouth for a stronger signal
In Overcombe, 3 km north-east of Weymouth town centre, ITU-R grade 5 reception is possible from Weymouth where the field strength is in many places in excess of 80 dBµV/m. Where we checked, reception is only available from this transmitter. Digital Terrestrial Television is not available in this area. The vast majority of roof-top aerials are ‘Contract’.
Recommendation:  replace ‘Contract aerials’ with new digital ready aerial installations
Wyke Regis is less than 2 km south of Weymouth and all viewers with roof-top aerials are using this relay. The field strength from Weymouth is around 90 dBµV/m but the picture quality is affected by DII (Delayed Image Interference, i.e. ghosting) and CCI (Co-Channel Interference) at ITU-R grade 4. Digital Terrestrial Television is available on some multiplexes from Stockland Hill. There were many poor quality aerial installations seen in the area. No aerials were seen on housing built within the past decade.
Recommendation: install good quality antennas e.g. stacked aerials or aerials with a good front/back ratio e.g. grid aerial
On the Isle of Portland in Fortuneswell, ITU-R grade 5 reception is possible from the Beacon Hill and Stockland Hill main stations. The field strength from Weymouth is around 70 dBµV/m but the picture quality from Weymouth is affected by Delayed Image Interference (“ghosting”) and Co-Channel Interference at ITU-R grade 4. Digital Terrestrial Television is also available on some multiplexes from both Beacon Hill and Stockland Hill. There were many ‘Contract’ roof-top aerials seen and a number were old and in need of replacement.Recommendation: replace ‘Contract aerials’ with new digital ready aerial installations using Beacon Hill or Stockland Hill (which should provide full DTT coverage on the three main Public Service Broadcasting multiplexes at the time of switchover)

On the Isle of Portland in Easton, Weston and Southwell, coverage is primarily from Stockland Hill and was assessed as being at ITU-R grade 5. Beacon Hill reception is affected by Co-Channel Interference from Digital Terrestrial Television services and in places by Delayed Image Interference (“ghosting”). Digital Terrestrial Television reception is not available. The vast majority of aerials were directed towards Stockland Hill. About 50% of these are ‘Contract’ aerials and in our estimation have been in place for many years.
Recommendation: replace ‘Contract aerials’ with new ‘digital-ready’ installations using Stockland Hill  
In Dorchester most viewers were receiving Rowridge main TV station. At some locations, analogue TV reception is affected by Co-Channel Interference from both analogue and Digital Terrestrial Television transmitters. Digital Terrestrial Television reception is available on some multiplexes from Rowridge. Interestingly analogue reception is also available in some areas from Piddletrenthide and Winterbourne Steepleton relay stations, but again like Rowridge it is affected by Co-Channel Interference. We did not see any viewers in Dorchester using either Piddletrenthide or Winterbourne Steepleton.
Recommendation: install good quality aerials e.g. stacked aerials or aerials with a good front/back radio e.g. grid aerial
Viewers in Charminster, 2 km north of Dorchester, use both Rowridge (BBC South) and Stockland Hill (BBC South-West) in equal measure. Approximately 80% of installations are good quality aerials with many using masthead pre-amplifiers.  This indicates that reception can be problematic in this area and that viewers have to make special efforts with the quality of their installations – this may explain the relatively high number of reported problems in this area.
Recommendation: check condition of existing installations and replace any ‘Contract aerials’ with good quality aerials
Charlton Down, 4 km north of Dorchester, is a rapidly growing village with a significant number of new houses and dwellings under construction. Much of the new build is near the valley bottom, and we suspect poorly served. It may be worth investigating the quality of reception when the development is complete. Currently about 50% of houses have satellite dishes. Only 33% have roof-top television aerials, all were directed towards Rowridge and, of those, half were ‘Contract’ aerials.
Recommendation: replace ‘Contract aerials’ and in new areas of poor reception, recommend satellite reception
We also visited Osmington. Coverage in low lying parts of the village fails to meet standards normally necessary for satisfactory reception. This is a known deficiency with, in 1984, two hundred and forty people considered unserved. Roof-top aerials were on tall poles, of good quality and some were seen to have masthead pre-amplifiers. A number of dwellings were seen to have satellite dishes.
Recommendation: use good quality receiving installations with masthead amplifiers or satellite reception

     Throughout the note, where a place name is in italics, it is referring to the television transmitter at that location.

     The ITU-R assessment of picture quality is on a 5 point scale and defined as follows, based on the observed level of noise or interference on the picture:
Grade 5 - Imperceptible
Grade 4 - Perceptible but not annoying
Grade 3 - Slightly annoying
Grade 2 - Annoying
Grade 1 - Very annoying

Grade 5 or 4 pictures are considered excellent or good and a full service is considered as being at grade 3.5 for noise or grade 4 for interference.  Lower grades of picture quality may be watchable but less good.

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