All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Clare McNeil: My point was one of getting things into perspective from the point of view of the likelihood of each happening, the likely detrimental effect and the ease of enacting a solution.
I imagine that in most cases where interference is an issue that a filter will cure it. Only in extreme circumstances will a filter not rectify the issue, this being where the interfering signal is so strong.
Filters have been sent out to addresses where interference "may" be an issue. Understandably, this may provoke concern among recipients, but at the end of the day the other alternative would have been not to send them out automatically, leaving those who are affected (having turned on the 4G masts) to ring up and request a filter.
As I guess it will say in what you have received, the organisation that is carrying out the test is "at800". They say that if, during the test, viewers experience interference that they should ring them. An engineer will visit to find out what the issue is:
at800 Brighton 4G test
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Clare McNeil: I hope that we have allayed your concerns and put your mind at rest.
Should you have an issue when the test starts and the filter doesn't cure it, or you would like assistance fitting the filter, then at800 are the people to call.
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Toni B: Perhaps it is a combination of the trees and the traffic on Lymington Road, which intersects the signal path. I offer the latter as a possible explanation of why the reception varies at different parts of the day.
I say this because, in the direction of the transmitter, the ground rises before the water. See the terrain plot:
My Freeview | ukfree.tv - 10 years of independent, free digital TV advice
Imagine if the transmitter were beaming out light. The line between it and the receiving aerial is likely to be obstructed by objects on the ground. Vegetation and traffic change over time and so their effects on reception may change.
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pete: No. The UK now has a two-tier terrestrial transmitter network. This is because there are two types of broadcaster.
The Public Service Broadcaster (PSB) channels transmit from the Weymouth relay. There are over 1,000 other low power transmitters which serve about 8.5% of the population which also only carry PSB channels.
As well as Public Service Broadcasters, there are now Commercial broadcasters (COMs) which have no obligation to provide a "Public Service", only make profit. For this reason they only broadcast from the largest transmitting stations and are therefore not "missing" from any transmitting station as it is their choice as to which they serve from.
For a further explanation, see:
Londonderry (Northern Ireland) digital TV transmitter | ukfree.tv - 10 years of independent, free digital TV advice
It is doubtful that you may be able to receive the full service (from another transmitter). As well as having inferior coverage due to not being carried from all stations, there are some who can only receive PSB stations reliably even though they are using a full-service transmitter. This is because the signals aren't as good as well as the frequencies they use being reused by transmitters in closer proximity than the PSB frequencies are reused.
The COM channels from Stockland Hill share frequencies with the COM channels of Rowridge, so at your location you "may" find that this rules out reception of the full service from the latter. That said, Rowridge's channels are vertically polarised and Stockland's are horizontally polarised.
See if any of your neighbours have aerials directed to Rowridge which is on a bearing of 84 degrees. Rowridge broadcasts horizontally and vertically now, albeit that the COM channels are better with the latter. The fact that someone has an aerial pointing to it does not necessarily mean that they can pick up all channels.
You may give consideration to Freesat, particularly if you are unable to receive the Freeview COM channels.
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Malc: Is this a channel which you had previously at this location and has disappeared? Is it one that you have lost since you moved?
Which transmitter are you using? Sheffield, with your aerial vertical, or Emley Moor with your aerial horizontal?
Do have the other Commercial channels Pick TV (11) and Film4 (15)?
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Jon Rhys: Did the deterioration coincide with the erection of a new building?
The Megalithia terrain plot also provides a map with a line linking the transmitter and receiver (click the link "view a map of area..." below the plot. The terrain plot shows that about a mile away the ground drops a bit:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
The line goes through the east end of Bridgend Industrial Estate. This is what made me wonder if this is a new industrial building.
Looking at Streetview photos, it's quite clear that there are trees that may be difficulty for at least some residents. Add to that the fact that it is on a slope which means that the tops of buildings going upwards are higher.
It might be worth checking that they are tuned to UHF channel 42 for COM4 (ITV3) and not UHF channel 48 which is Mendip. Mendip is only nine degrees clockwise of Wenvoe.
If it is tuned to Wenvoe, they may be lucky and be able to receive COM4 from Mendip and the rest from Wenvoe. This may be a long shot but its free so it's got to be worth a try.
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Jon Rhys: It is not necessarily a building along the line, but one off at an angle to the receiving aerial.
The 800MHz 4G tests are certainly not an issue as they are a long way away.
Unless the receiver is tuned to the wrong transmitter or the desired transmitter has changed then nothing will be achieved by retuning. A receiver will lock on to the signal if it is there. Retuning cannot make a signal that is not there or is poor, appear or improve.
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Maurice: As you live in a block of flats, it may be the case that you are using a communal aerial system. If so then see if any of your neighbours have lost BBC services on Freeview.
Be aware that those receiving via satellite (Sky, Freesat etc) will not be affected, so try and ascertain that any who are not affected are actually using the terrestrial aerial system (Freeview).
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Jean: Looking at the location of Seven Sisters, I think it's doubtful that you will be able to receive the full service.
The UK now has a two-tier terrestrial television transmitter network. See here for an explanation:
Londonderry (Northern Ireland) digital TV transmitter | ukfree.tv - 10 years of independent, free digital TV advice
The difficulty you have is that you are in a valley and the signal is way above you.
Perhaps Freesat is your best bet for additional channels.
The only thing I can suggest so that your mother does not have more channels than you is, next time you are round her house, you untune the Commercial channels leaving her with only the Public Service ones (which are those you have)...
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Friday 10 May 2013 7:38PM
Clare McNeil: I really wouldn't be so concerned. Surely there are more important things that "might" happen to worry about, such as if one still has a job in six months time.
If there is interference from 4G services at 800MHz then worrying about it will make no difference.