All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
KR: Ensure that your booster isn't amplifying the signal too much as that could be a cause of poor reception.
The objective isn't to get the signal strength as near 100% as possible. There is a threshold above which it works. You just need to be sufficiently above this threshold that natural variations in signal strength (due to weather etc) doesn't drop it below the threshold.
Failing that, you could always try the Kimberley transmitter as it is a full-service one and broadcasts the same regional programming as Waltham.
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KR: See
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
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Kerry : No, not a quality issue.
Is the 40-46% with the set-top aerial or the roof-top aerial?
If it is the roof-top aerial then are you very close to the transmitter?
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Peter: Because you're receiving them from Black Mountain and not Divis!
Black Mountain is a Public Service relay which means that it doesn't transmit the Commercial (COM) channels which are SDN, ArqA and ArqB.
Divis is on a bearing 280 degrees and your aerial will be horizontal. Black Mountain is at 232 degrees and your aerial will be vertical.
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Kerry : In view of your location, scrap the idea of trying a set-top aerial if you do not have one.
Set-top aerials pick up less signal than roof-top ones owing to the fact that they are closer to the ground and smaller. The idea was a rough test to see if it is too much signal.
As you are 30-odd miles from Brougher Mountain, you must have only just picked up the 500W pre-switchover signals. You were lucky!
The Digital UK Postcode Checker gives an indication as to what might be expected to be received. It does not even mention Brougher Mountain at all but regards Divis' PSBs as being "good". I think that this pretty much wipes out any hope of receiving Brougher's COMs as they are on the same channels as Divis' PSBs, this even being the case if you are in a location where Divis isn't useable but is sufficient to severly degrade reception of signals that share the same channel.
The design of the post-switchover Freeview network is such that the PSBs are available in all the locations (i.e. have the same coverage) as the former analogue. The COMs fit in around them. For whatever reason, presumably shortage of channels, Brougher Mountain's COMs have been put co-channel with Divis' PSBs and the obvious overlap of these two main transmitters means that the former has had to be severly restricted.
Do you know why you receive from Brougher Mountain rather than Divis? Having looked at the map, I suspect that you are going to tell me that the Crockandun Hills are in the way.
If you can receive from Divis, its COMs are on lower power than its PSBs and Digital UK suggests no reception of the former, whilst good reception of the latter. For this reason the likelihood of receiving anything more than you do now is doubtful.
I must emphasise that the predictor should be used as a guide and taken with a pinch of salt and this particular being the case in hilly terrain like where you are. What can and can't be received can vary over short distances, meaning that an area the size of a postcode can vary greatly.
If it turns out that it isn't possible to receive more channels than you do now terrestrially, then the only way is via satellite, the main free-to-air service being Freesat.
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Anthony Murray: It looks as though these two TVs don't have a HD tuner in-built.
I couldn't find the official specifications page on the Panasonic website, but I did come across listings on Play.com and eBay for it and both said that it is "HD Ready". This means that it won't receive HD signals, although I think that some people may have bought such sets prior to HD signals coming on air (i.e. before switchover) with the thinking that they will be "ready" to receive HD when it comes on air.
The specs on the Sony website say that it is "Full HD" rather than "Freeview HD". Full HD means that it will show HD pictures to the highest resolution of 1080p:
http://www.sony.co.uk/pro…#tab
The Sony website also says that the digital tuner supports MPEG2 so it won't show pictures with Saorview (as this uses MPEG4).
Freeview HD receivers are expected to work with Saorview.
Try a manual tune on C52. The TV may tune it but show no picture but will nonetheless indicate if you can receive Saorview.
In order to receive the NI Mux from Black Mountain on C39 you will probably need the diplexer removing (and hence the Clermont Carn aerial disconnected).
Realigning the Clermont Carn on Black Mountain "may" work (this includes retaining the diplexer), although as the diplexer "splits" at C38, adjacent channels are attenuated quite a bit so this could perhaps be doubtful:
Online TV Splitters, Amps & Diplexers sales
In a stronger signal area, this attentuation might not have been such an issue.
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adrian: You may perhaps need to be aware that the RT channels carried on Freeview that you are trying to receive are being broadcast from Black Mountain rather than Divis.
In many cases Divis-facing aerials will be sufficient in cases where Black Mountain isn't too far off Divis.
If this is your problem, you may be able to turn your aerial a bit so it points somewhere inbetween the two. In north Belfast I think this means that aerials may need to be turned a tad in the anti-clockwise direction.
The other thing is if you have a second aerial that you used to use for analogue RT and this is connected (perhaps on the roof) to the same downlead cable, then it may need removing in order to receive the NI Mux. If you do have such an aerial, then try manually tuning the digital (Saorview) signal for that transmitter. The most likely transmitter that you would be receiving from is Clermont Carn which is probably a bit clockwise of south with the aerial vertical and it broadcasts on UHF channel 52. When manually tuning, select DVB-T rather than DVB-T2, if it gives you the option.
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adrian: Try tuning in the NI Mux from Black Mountain. It is on C39 and uses DVB-T2 signal mode, so if your I-Can gives you that option (I'm not familiar with them), then you need to select it.
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Kerry : I should add that (maybe) "never say never" as far reception from Divis is concerned.
In the days of analogue (when the aerial was put up), Divis and Brougher Mountain provided the same four channels. Thus the question posed by the installer would have been one of which is best? This doesn't necessarily mean that it isn't possible to receive from Divis now it's digital.
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Gez: Switch your aerial to vertical polarisation to take advantage of the stronger signals on the COM channels (of which Yesterday is carried on one of them).
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Hannah Chacko: Being tuned to the signals from the transmitter to which the aerial faces is pretty fundamental to good reception!
If your aerial faces south, then it is pointing to Waltham.
Attempt a manual tune on UHF channel 29 which is the missing multiplex (COM4/SDN). Try turning your booster down a bit, say to give about 70% on other channels.
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Donald Clark: This is how it is likely to stay. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Unless you can receive from another full-service transmitter, then you won't receive the Commercial (COM) channels. In some areas another region's full-service transmitter can overlap and be used in conjunction with the local relay but the hilly terrain you live in probably rules this out.
Judging by the coverage maps on this site, then if you live high up, then you "might" be able to receive the other channels from Lancaster transmitter.
This isn't the answer you might have been hoping for, but I make this simply as quite possibly the only way, if indeed you are lucky enough to have it as a possibility.
Additional channels are also available via satellite, the main free-to-air service being Freesat.
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Hannah Chacko: The only observation I can make (not saying that this "is" the problem) is that Bilsdale which is the southern-most main Tyne Tees transmitter switched to digital on 26th September and it uses C29. Waltham doesn't share any other channels with Bilsdale.
I would be surprised if the Bilsdale signal were to affect reception in the loft at your distance but they do say that TV reception is a black art.
Digital UK reports possible weak signal, so it could always be that:
Digital UK - Planned Engineering Works
It certainly wouldn't be worth doing anything with the aerial until the engineering work has completed.
Can you not have the aerial outside?
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Gez: In which case, it is probably your landlord who is responsible for the system. See if your other neighbours have difficulty with reception of Yesterday and other COM6/ArqB services.
See here for services by multiplex:
DTG :: DTT Services by Multiplex
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Hannah Chacko: Bring up the signal strength screen and ensure that it is tuned to C29. Other possibilities may be C30 (Belmont), C51 (Emley Moor), C42 (Sutton Coldfield).
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Ian Drury: Digital pictures are an all or nothing sort of thing. There is very little inbetween where they break up a bit. It is said that there is a "cliff edge" over which the picture can't be resolved.
If it is interference, for example from Fanad, then it could have been that, previously, whilst the picture was "perfect", the signal was being interfered with, but not to the degree to push you off the cliff.
What this means is that there is only a "slight" change to the level of degradation required to move from "only just" being good enough (which produces a "perfect" picture) to "only just" being not good enough (which produces no picture).
Such a change could have come about due to a change in the Fanad signal (if that is what is the cause) and this may be something that has moved and is causing a reflection in your direction. Or perhaps there was something that was acting to block or reduce the signal from Fanad that has now moved. Or maybe something has acted to reduce the signal from Limavady.
I mentioned that Fanad is co-channel simply as an observation. If you could receive analogue from Fanad (to some degree, even if not watchable, and particularly so on your Limavady aerial), then this might perhaps add weight to its digital signal being a possible cause of your woes.
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Ian Drury: Should it prove to be interference from Fanad and you have a grid aerial, such as that shown in this picture, then perhaps a more directional aerial will be better:
Aerials, TV Aerial and Digital Aerial
Grid aerials have a wide acceptance angle and therefore less gain than more directional ones. This is because to get more gain, the aerial simply focuses on a narrower "beam".
Both Holywell Hill and Limavady are on similar bearings and a grid aerial with its wider acceptance angle would therefore be perfect for such an application. However, its wider acceptance angle leaves it open to picking up interference that a more directional antenna would be likely to "reject".
Obviously if the interference is eminating from the direction of the transmitter, then a more directional aerial will still pick it up.
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Martin Engwell: Thetford only carries Public Service (PSB) channels. It also uses Group A channels so a Group C/D or Group E aerial for Tacolneston won't really be suited to Thetford.
You say that putting the aerial on the roof won't overcome the interference caused by the tree. The signal outside will be stronger than in the loft, as it is higher up and doesn't have the roof tiles in the way.
I write here in general terms, as a non-professional.
For lots of information on reception, see A.T.V (Aerials And Television) TV Aerial, DAB Aerial, FM Aerial.
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Martin Engwell: You may end up no better off with Sudbury as with Thetford as the prediction is that you will likely only be able to receive its PSBs.
Of Sudbury's COMs, C56 and C58 are used by Waltham. C60 isn't used by Waltham, although it is used by Oxford and Belmont (which are further away). The prediction for it is "poor".
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Rob: They are never likely to broadcast from the Banbridge transmitter. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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Sarah: Assuming that your aerial points to the Crosspool transmitter, as all the aerials on your street appear to be, then you need to manually tune to C39 for COM6 which carries Film4 and Yesterday.
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Sarah: What I am wondering is if there is too much signal. A set-top aerial by its nature picks up less signal due to it being lower to the ground and smaller.
If you have any booster fitted, then remove it (unless it's used to split the signal several ways).
Too high a signal level can appear as too little a signal. That is the higher the signal goes over and above the receiver works reliably at, the more it gets overwhelmed by signal and starts to show poorer quality signal and lower strength. Sometimes this can cause the strength to jump up and down.
I imagine that you might be able to see the transmitter from your roof-top.
See:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
Variable attenuators are available online from such sources as eBay (other retailers are available), for example:
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
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norm: Carnmoney Hill does not broadcast the Commercial channels and is not likely to ever do so. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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john: As Guisborough sits at the bottom of the moor which carries its name and there are trees on the slopes, it is probably the case that quite a few people in Guisborough will only receive PSBs.
This is because the Guisborough relay transmitter carries only PSB channels and because, for those who receive from Bilsdale directly, its COM channels (those not carried by Guisborough and which you have lost) are on lower transmission power than its PSBs and they use a less robust (less fragile) signal mode.
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john: The "less fragile" should say "more fragile".
Imagine if the signals were a courier service where fragile parcels a received broken but non-fragile ones aren't (i.e. they don't bash them about enough to break the non-fragile ones).
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Don: After switchover, the Freeview network is a two-tier system, as you have found out. Whilst all transmitters carry PSB channels and so serve the same areas as the former analogue, a lot of small transmitters like Lisbellaw don't carry the COM channels. For a list of which are PSB and which are COM, see:
DTG :: DTT Services by Multiplex
The other thing is that of those that do carry the COMs, they are on lower power than the PSBs and hence some on the fringes can only receive PSBs.
From Brougher Mountain there is a very marked difference between power of PSBs (20kW) and power of COMs (2kW). Most that are different have COMs at half power to the PSBs.
If people were receiving the pre-switchover digital from Brougher Mountain with their aerials directed to the Lisbellow relay (which at that time only carried analogue), then from an engineering point of view they were lucky. For reception from Brougher Mountain a Group A aerial is required in areas where the signal is not so good, as I assume it is so in your general area which is why the local relay was installed.
Unless reception of the COMs is possible from Brougher, then there is no advantage to be gained from receiving from it when the signal from the local relay is available.
The marked difference in the strength of PSBs vs COMs could be an issue with tuners desensitising themselves as a result of the high power signals thereby not being sensitive enough to pick up the lower powered ones. Careful adjustment of an amplifier or adjustment of an attenuator may strike a ballance allowing both to be viewed.
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Elizabeth Bellamy: See:
Gold replaces LBC on MXR Yorkshire DAB : Radio Today with RCS
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Don: For receivers with manual tuning (which all "should" have), try tuning in to 21, 24 and 27 which are the COM channels.
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Jim Neary: The oscillation suggests that it could be too high a signal level. Try turning your amplifier down.
According to RTNL, only Kippure broadcasts on C54:
http://www.rtenl.ie/wp-co….pdf
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Rita Mc laughlin: Because all platforms are listed. Underneath each platform's icon, it gives the respective logical channel number. The absence of a number means that it is not available on that platform.
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John: I replied to your message earlier today!
Updated - changes to Freeview channel numbers this week on September 19th 2012 | ukfree.tv - 10 years of independent, free digital TV advice
If you are using the Guisborough transmitter, then it doesn't broadcast the Commercial channels and therefore you are receiving what is being broadcast.
Which transmitter you should be tuned to is that which your aerial faces. As the aerial is on your house, then surely you should be the ones telling us!!
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John: From what you're saying, your aerial must be pointing to Bilsdale rather than the local relay transmitter as it only carries PSB channels.
The COM channels (those that you've lost and which Guisborough doesn't broadcast) are on lower power from Bilsdale than its PSBs (those that Guisborough doesn't transmit). Consequently there will be some on the fringes who will only be able to receive PSBs from Bilsdale (same as the channels broadcast by Guisborough).
Some (who receive from Bilsdale) will have intermittant reception of COMs as digital is an all or nothing thing.
Your TV may tune to another transmitter (one which the aerial doesn't face) as a result of its automatic tuning function and if this is the case, then it needs addressing or you are likely to have intermittent/poor reception because you are using the aerial to receive from a transmitter it doesn't face.
Some receivers automatically tune at will when unattended and in situations where this results in being tuned to the wrong transmitter, then this is obviously a nuisance. In some cases this "function" (I use the term loosely!) can be turned off.
What you need to do is check to see what transmitter your receiver is tuned to for each signal (known as a multiplex):
PSB1 | BBC One | Bilsdale=C26 (Guisborough=C57)
PSB2 | ITV1 | Bilsdale=C29 (Guisborough=C60)
PSB3 | BBC One HD (if applicable) | Bilsdale=C23 (Guisborough=C53)
COM4 | ITV3 | Bilsdale=C43
COM5 | Pick TV | Bilsdale=C46
COM6 | Film4 | Bilsdale=C40
View the signal strength screen whilst on each of the above services (BBC One, ITV1, BBC One HD) and ensure that they are tuned to UHF/RF channel numbers 26, 29 and 23 respectively. If any are on 57, 60 and 53 then they are being received from the Guisborough relay.
If any are being received from the Guisborough relay, then run the automatic tuning scan through and unplug the aerial when it gets to 55% (or past C46 if it gives channel numbers during the scan). You will note that Guisborough uses higher channel numbers than Bilsdale which is why I say unplug the aerial so as not to have it plugged in when it scan Guisborough so it doesn't pick them up.
If, after doing this, any or all of the COMs are missing, then, if your receiver allows, go through to the manual tuning function and tune to 43, 46 and 40 (for ITV3, Pick TV and Film4 respectively).
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John: Knowledge of the model of your TV or set-top box might be useful, especially if I can find its user manual online.
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Tony : That Samsung set cannot receive Freeview HD signals which use DVB-T2 mode. If you are receiving the Irish channels from Black Mountain then this also uses DVB-T2 mode, even though the pictures are standard definition.
Alternatively, if you are receiving the channels directly from one of the Republic's transmitters, then these use DVB-T, but Saorview pictures use MPEG4 format. (Freeview standard definition pictures use the earlier MPEG2 format.)
The information about this model is here:
Support for PS50A457P1D
Page 2 of the manual says "Any functions related to Digital TV (DVB) will only work in countries or areas where DVB-T (MPEG2) digital terrestrial signals are broadcasted."
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Clive B Hill: Run the automatic tuning scan with the aerial unplugged for the first 50%.
The problem is most likely to do with the fact that when the TV scans the frequencies it starts at low frequency and works upwards. BBC from Winter Hill is the highest of the lot, so if it has found others then these have probably filled its memory. The trick, therefore, is to prevent it from "finding" the signals from other transmitters that you aren't interested in, so as to leave space for the one you are interested in.
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Ian Stewart: Is the aerial a wideband or Group K one?
Former Group A aerials may need replacing. Or perhaps you are on the fringes of the COM channels from Craigkelly (which are lower-powered than the PSBs).
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Peddyr: Look at the radiation pattern on Kippure's page, it looks like IoM is in the main null, although the Lln Peninsula of Wales appears to be served!
Why do you want the NIMM as Clermont Carn will give you all the same channels and more? Plus if you can receive (at least) the COMs from Divis you have all the Freeview channels as well.
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Peddyr: I wonder if it is possible for the EPG data for Freeview NI and Saorview to be shared and if the authorities would do it. There is a large portion of Northern Ireland that can receive the Republic's signals so they must all be in the same boat.
I suppose that you must have the same issue when using one of the IoM relays and Divis.
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Steve: The "problems" that are reported are those issued by the broadcasting authorities rather than those of viewers.
The Commercial (COM) channels from Rowridge aren't as strong horizontally and this is because they overlap with Stockland Hill and Crystal Palace which uses the same three channels. The weaker signal and high error rate "could" be a symptom of that, the remedy being to switch the aerial to vertical polarisation to take advantage of the stronger COM signals and "rejection" of a co-channel transmitter.
This assumes that you haven't already switched your aerial.
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Steve: Since the changes in April, Rowridge transmits vertically as well as horizontally.
The PSB (Public Service) channels are 200kW horizontally and 200kW vertically. The COMs are 50kW horizontally and 200kW vertically.
The main reason for the horizontal signals are for backward-compatibility with aerials that are already fitted (horizontally).
I mentioned aerial replacements, but they shouldn't (generally speaking) be needed for Rowridge and a wideband aerial isn't needed. These tend to have less gain on the (lower) channels/frequencies that Rowridge uses so a Group A aerial (the "non-wideband" type you probably have) is the best. Turning it to vertical should do the trick.
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dan: Assuming that your RT aerial is vertical and points to Clermont Carn in Co. Louth, then you need to manually tune to UHF channel 52.
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Steve: If you are looking for an aerial or information on them, see ATV's site:
Rowridge Transmitter
If there is a good clear path to the transmitter, then the signal could be a bit on the high side. The effect can appear the same as too little a signal:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
An attenuator may be useful, e.g. (other suppliers are available):
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
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steve: The most common answer to such a question is because they do not have HD (DVB-T2) tuners in.
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Peter: Have a look at www.mb21.co.uk
It appears to be down at the moment, but the Transmitter Gallery has BBC coverage maps for UHF and BBC Local Radio. I've not noticed that there are the maps you are looking for, but you may find them.
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john: Did you ever have your Group A aerial replaced? In the days of four-channel analogue, aerials were usually installed that were sensitive over the "Group" of frequencies that the transmitter in question used. Each Group is a third of the band and Group A is the bottom third.
The channels you have lost are on higher channels/frequencies which are in Group B (middle third). Whilst aerials aren't sensitive to absolutely nothing out of their designated Group, they are less sensitive (how much varies by model).
Group A aerials have red tips, widebands have black tips and Group K have grey tips.
Group K can be thought of as a "semi-wideband" aerial as it combines Group A and Group B which would obviously be suited to the signals from Bilsdale (providing they are sufficiently strong at your location).
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Andrew scott: The Commercial (COM) channels are never likely to broadcast from Kilkeel transmitter and over 1,000 other similar small relays. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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Judi Palmer: During the recent changes the HD services moved from the 50s to the 100s. There were no changes to the standard definition Public Service services which are those offered by the Kendal transmitter.
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Judi Palmer: No, the Public Service-only transmitters like Kendal are likely to stay that way:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
It won't be a given receiving the other channels from Lancaster. It is 16 miles away and Well Heads Hill and Heversham Head are 10 or 20m above line-of-sight to the transmitter. The COM channels (those that Kendal doesn't broadcast) are on lower power from Lancaster than its PSBs (those Kendal does broadcast).
The photos taken of your road by Streetview in March 2009 show a few aerials on Lancaster, although this is no guarantee that all services will be being received. Due to the lower-power COMs, these viewers may only have the PSBs.
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j Noble: Relay transmitters by their nature cover small areas. So the fact that the "vast majority" of them don't carry the NI Mux (NIMM) does not mean that the vast majority of the population cannot receive those services.
See here:
http://consumers.ofcom.or….pdf
Ofcom estimates that around 94% of the population of Northern Ireland will be served by either overspill from the Republic's transmitters and/or the three NI Mux transmitters.
This website is an independent site here to help with advice. As identified in the Ofcom leaflet linked to above, you need to address your comments to Multiplex Broadcasting Services N. I. Limited which runs the NI Mux.
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Neil: You will be unlikely to receive anything more than the Public Service channels. This is because your local transmitter is Cornholme which does not broadcast the Commercial (COM) channels, which carry Dave among others.
This isn't likely to change as the Commercial broadcasters don't wish to pay to transmit from the small sites. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Unless you can receive all services from a main station such as Emley Moor, then you won't ever receive them on Freeview.
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David Irwin: I can't find a transmitter that uses C39 for PSB2 (UTV/C4 etc) either. I checked the Digital UK Postcode Checker and the Ofcom Tech Guidance document and they both bear out what I've put below:
http://stakeholders.ofcom….pdf
In your general area there are two relays that each use the same three channels, albeit with PSB1 and PSB3 swapped:
- Kilkeel: PSB1=C45 PSB2=C42 PSB3(HD)=C39
- Rostrevor: PSB1=C39 PSB2=C42 PSB3(HD)=C45
So you are receiving from Kilkeel. Rostrevor is 23W and Kilkeel is 400W. Perhaps you should probably re-orientate your aerial to the latter.
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Mike Wells: The Mendip aerial may be a Group C/D one. If it is a wideband aerial, then this will work to a degree for Rowridge. Wideband yagi aerials aren't as good for Group A channels, of which Rowridge uses exclusively:
Aerials, TV Aerial and Digital Aerial
It's not possible to receive horizontally and vertically at the same time with a yagi aerial.
Rowridge broadcasts PSBs at 200kW horizontally and vertically. Its COMs are 50kW horizontally and 200kW vertically. The restriction horizontally is primarily due to the overlap with Stockland Hill and Crystal Palace which use the same three channels (but don't share PSB channels).
The Digital UK Postcode Checker suggests "good" reception of Stockland Hill's PSBs and none of its COMs. The same goes for Rowridge for both polarisations. Whilst it should always be born in mind that such predictors are calculated and may not be what is found to be possible, it could suggest that the only transmitter you may pick up the COMs from is Mendip.
It is possible that even though the vertical signals from Rowridge are the same power that they don't serve the same areas because the radiation patterns are different. For example, maybe its COMs are restricted to the south for international reasons. Similarly, maybe they are restricted in the direction of Stockland Hill so as not to interfere. This is possible speculation on my part which may be worth bearing in mind.
Refer to this page:
The commercial multiplex after switchover: ArqA, ArqB and SDN | ukfree.tv - 10 years of independent, free digital TV advice
It shows that around one third of Rowridge viewers are likely to be unable to receive the COMs.
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lee ambler: I'm not an aerial installer/professional myself, so am offering comment as a technical bod.
It would seem reasonable to be of the opinion that in the situation you describe, Ventnor is quite likely to wipe out reception of Midhurst's C54.
Ventnor is due to relinquish use of C54 in May.
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Mike Wells: As I have explained, the main thing it would depend on is if the Mendip aerial a Group C/D one. If it is then it isn't really suited to a Group A transmitter, which Rowridge is.
You cannot really use two aerials simulataneously, one horizontally and one vertically so I don't understand what you are thinking that will be gained.
There is an element of doubt as to whether you will be able to receive the COM channels from Rowridge, even with the aerial vertically orientated. This would tend to suggest that your chances of success might not be great and hence you need to use a Group A aerial for all the gain you can get.
If it proves that you can't receive the Rowridge COMs, then you need a diplexer to combine the Mendip aerial with the Rowridge one to give you Mendip's COMs and Rowridge's PSBs.
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Michael: If your aerial is directed to Brougher Mountain, then try a manual tune on C30. Select DVB-T2 mode, rather than DVB-T if the option is presented within the manual tuning function.
If your aerial points to Strabane, then it doesn't broadcast the NI Mux/RT.
One observation I have made it that Holywell Hill also broadcasts on C30 horizontally, so if you happen to be in a spot where it comes in well, then you may have an issue.
An aerial is an aerial and is not special for reception of digital signals, above that of former analogue ones. Brougher Mountain is all Group A (including the NI Mux), so the (Group A) aerial used for former analogue should work.
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KR: The thing with digital reception is that there is a lower threshold above which the picture resolves*. There is an upper threshold over which receivers are overloaded (with too high a signal level).
* This assumes a good quality signal. If a poor quality signal (i.e. effectively the digits that make up the picture are corrupted) is received, even if the magnitude is within the window between the lower and upper thresholds, then the picture will be poor or non-existant.
And so, theoretically, the target is to have the signal somewhere within the window such that natural variances in level (e.g. caused by the weather) don't result in it dropping below the lower threshold or pushing it above the upper one.
Running at almost the top of the window provides no benefit from a picture quality point of view over running it mid-window, for example. The only downside is that it might go OTT which causes break-up which is largely the same effect as caused by too little a signal. Oh, and of course your wife won't be happy either.
The manual for the Philex SLx6 distribution amplifier is here:
http://www.philex.com/ass….pdf
Under the "Troubleshooting" heading it mention that too much signal can be problematic for digital reception. However, it doesn't, apparently, offer any adjustment on its amplification level (which is +12dB per output) which is surely required!
I'm not an aerial professional, just a technical bod. However, if the signal coming out of your aerial (and being fed into the amp) is at a suitable level, then the six output feeds are +12dB up. There are obviously losses in the downleads, but unless you live in a mansion where there are long runs to the outlets, then I don't think that they will anywhere near cancel out this increase.
The strength meters on receivers are nowhere near scientific measurements and therefore vary between models. Using the same receiver on different outlets provides for a more accurate comparison. The Humax box is a good model to use for testing purposes.
A 100% (or anywhere near) strength may be verging on the top of the window of acceptability. Therefore a lower reading may be better.
As jb38 says, it is worth bypassing the amp by connecting the feed from the aerial directly to each room feed in-turn.
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David Arthur: The transmitter went off, so why retune? If you hadn't done it, then you wouldn't have been in this position!
The question is, which other transmitter are you picking up?
Upavon uses channels 23, 29 and 26 so if the other BBC South (and any others) are coming from a transmitter above the 20s, then you can avoid them by unplugging the aerial after 30%.
Bring up the signal strength screen whilst on the erroneous BBC One South and it should tell you what UHF channel it is tuned to. Looking at the map, Shrewsbury is probably the most likely and it broadcasts on C57 (and is also vertically polarised). In which case the unplugging aerial trick will definately work!
If it is on C24, then that is Rowridge and will be more tricky.
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David Arthur: If it turns out to be Rowridge, then can you wipe the memory and then try manually tuning? It may be a "try and see" as to what works. For example, running it through with the aerial unplugged may or may not work; perhaps a factory reset is the only thing.
Another possibility might be to reduce the level of the signals such as by reducing the amplification level of the powered splitter (if you use one). Or the Upavon relay may be receivable with a set-top aerial which will hopefully make the Rowridge signal unreceiveable. Once you have it tuned, then go back to using the roof-top aerial as it was before.
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David Arthur: The objective of reducing the level of amplification is in the hope that the unwanted BBC South signal will be reduced such that it won't be picked up, but that the Upavon signal remains. This is the same objective as using the set-top aerial.
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Victoria Thorpe: The Ventnor transmitter is to your north and the signal is therefore coming from that direction!
If you have found that you no longer have as good a signal on the south side then this may suggest that the reflection you were relying on is either being blocked or is no longer there.
Resetting the TV will do absolutely nothing, barring wasting time, if it is a lack of signal!
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Anthony Chaplin: LBC has been taken off the Yorkshire multiplex:
Gold replaces LBC on MXR Yorkshire DAB : Radio Today with RCS
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Keith: Divis uses only Group A channels and wideband yagi aerials are less efficient on those channels.
Use a Group A aerial:
Rowridge Transmitter
Digital TV Transmitters
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Gill: I experienced dj vu when I looked on Streetview at your block!
You made a posting in August which replied to:
Heathfield (East Sussex, England) full-Freeview transmitter | ukfree.tv - 10 years of independent, free digital TV advice
If your TV is tuned correctly to Heathfield for ITV3, then I suggest that the cause of poor reception is likely to be the same as why you are unable to receive COM6 (Film4, Yesterday, Magic etc).
ITV3 is on UHF channel (frequency) 42 from Heathfield, so bring up the signal strength screen and ensure that it is tuned to C42. Midhurst's ITV3 is on C54, so if it is tuned to it, then it needs correcting (assuming that your aerial faces Heathfield).
Prior to switchover, 41 and 42 weren't used for either analogue or digital and therefore may be being filtered out by your block's aerial system. This is a matter for those responsible for it to make necessary adjustments.
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a hollland: Freeview is a terrestrial system and Freesat is a satellite system. There are a few TVs that have Freesat built-in. I believe that they also tend to have Freeview as well, but you could just not use it.
A brief Google brought up these (and other) results:
freesat HD TV - freesat
http://www.sony.co.uk/hub…1947
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mark: If you can see the mast from your roof, then I don't understand why on earth you would have a high-gain aerial installed, let alone have it replaced!
Have you tried attenuating the signal?
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
For example (other models and suppliers are available):
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
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d.Gwilt: I think that you need to go to the opticians!
As stated above a number of times and in discussion with others the likely answer is NEVER.
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John Gallard: The usual cause of the services not taking up their designated logical channel numbers is because the country has not been set to UK/GB.
The only other thing that I can think is if you are in Northern Ireland where you may be bale to pick up Saorview from the Republic and that this is your cause of difficulty. If so, then perhaps avoiding having the aerial plugged in during the part of the scan that the Saorview signal is on might work. Knowledge of your location may help if this could be a possible issue.
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James Hyde: Relay transmitters mainly serve small areas that aren't otherwise served by high power "main" transmitters. They are so-called because they relay the signal from their parent, that is they receive it off-air and rebroadcast on their own frequencies.
As most relay transmitters only serve a small number of households, the Commercial broadcasters aren't interested in having them carry their channels. See here for an explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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martin cunningham: The reason that the Newcastle transmitter does not carry all the channels is outlined here:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Whether your house "may" be able to receive the full service from Divis cannot be answered without knowledge of where it is!
The difficulty in your general area with receiving from Divis is that Slieve Croob and nearby peaks are in the way.
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Mark Littlejohns: The 1,000 plus PSB-only relays aren't likely to be upgraded to provide the full service. Bath transmitter continues to relay only the three PSB multiplexes.
Identify which UHF channel (frequency) that the other channels are coming in on, and hence what transmitter they are coming from. Do this by viewing the signal strength screen whilst on the following: 10:ITV3 (COM4), 11:Pick TV (COM5) and 15:Film4 (COM6).
The three COM channels from Mendip are 48, 56 and 52 respectively.
The result for digital reception (a picture being shown) is pretty much all or nothing. Thus the signal level may have been "just below" before and is "just above" now which is a "slight" change. This is to explain why you may have no reception in one instance, and some in another.
Your aerial is obviously facing the wrong way, it is vertically polarised (Mendip's signals are horizontally polarised) and it is probably a Group A one (which is more sensitive on the lower channels that Bath uses and hence less sensitive on the highest channels which Mendip uses).
I wouldn't like to say whether you will be able to get continual reliable reception from Mendip even with your Bath aerial giving some sort of reception. A professional installer on-site is only likely to be able to say.
It is possible that you are receiving the Mendip signals because there is something that has changed and is reflecting them. Or they may have been there all along, albeit a "slight" increase. Or perhaps something in the path between the transmitter and you has changed and allows more signal through.
The difficulty with Mendip is that you don't have line-of-sight due to residing in a valley. This in itself does not necessarily mean that reception isn't possible.
Look around to see if others have had Mendip-facing aerials fitted. These will be horizontal roughly south west.
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David Brown: The Weardale transmitter at Frosterley does not broadcast any DAB. It relays the four BBC national FM radio stations only.
As the BBC has seen fit to install FM transmitters, then perhaps there are similar gaps in its DAB coverage.
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Keith: The sensitivity (gain) of an aerial isn't the same across all UHF channels/frequencies. For yagi aerials, the shape of the curve is broadly the same. See here for examples that illustrate my point:
Gain (curves), Again
The gain of wideband yagi aerials on Group A channels is much lower than C/D ones. That is why there is no such thing as a high gain wideband aerial that has "high" gain on Group A channels.
More gain in one direction is simply at the expense of more "loss" in others. So the "beam" of a higher gain aerial is narrower.
If your wideband aerial is sufficient for Clermont Carn, then there is no reason not to continue using it. The reason for suggesting use of a Group A aerial for Divis is because of the lower gain of the wideband aerial on its channels and the poor reception you are experiencing.
You need a diplexer to combine the two feeds:
Online TV Splitters, Amps & Diplexers sales
For Divis and Clermont Carn, get a diplexer that "splits" at C38. This will allow you to receive a multiplex from Divis on C36 should it ever come to fruitition.
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Martin Engwell: There are 101 reasons why the picture on one multiplex is affected and not on another.
Digital reception is more an "all or nothing" system rather than analogue whose picture varies relative to the signal.
Take signal level for example. There is a threshold over which the signal level must be in order for a receiver to resolve a picture. Providing that the quality is good, then the picture will be exactly the same as if the signal strength were higher (but not above being too high such that it overwhelms the receiver).
Thus, a reduction in strength will not have any effect on the picture unless the reduction is greater than the amount that the level was above the threshold.
A reduction in strength with an analogue picture is likely to have some degree of detriment to its quality but may still be watchable.
Because the quality of a digital picture isn't analogous to signal strength, then the effect (or lack of) on the picture is therefore not necessarily the same as that on the signal.
So you could perhaps find that if you used the appropriate test gear that the signal level on all channels has changed but that this has only adversely affected the resolution of the pictures on the BBC mux.
Another factor is that not all channels will be exactly the same. As they propagate they will be reduced and refracted to different degrees.
It is possible that they are using the reserve antenna which is further down the mast and as such the path or line between it and you may be different and importantly there may be other objects that are affecting your reception that wouldn't otherwise do.
I said that there are 101 reasons; these are just a few possibilities. The length of the aerial cable and differences in the receivers are two others.
I'm not a professional, but I would certainly not dismiss mounting the aerial outside as then the signal will not be reduced and refracted by the roof which might be helpful. The professionals do say that reception is a black art, so "common sense" of increased height doesn't always pay off.
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Pauline Colman: This sounds like some sort of interference generated by some noisy electrical appliance/device, perhaps in your house a that of a neighbour.
The fact that it happens at the same time suggests that it is something that is timed, although it could be something that is manually switched on by the user, just at the same time.
A noisy pump or motorised valve on a central heating/hot water system could be a possibility. Try turning such things off when it occurs to discount them as possibilities.
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bob: It's great to hear that you have the missing channels now and that it all came good in the end.
It is always the thing that you don't know whether and perhaps don't expect that the signals will improve at a later date. It turned out to be worth waiting rather than opting to incur expense changing the aerial, with such expense possibly only really being necessary in the mean time.
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Ian Humphreys: There are some "self-help" relays and information from Ofcom is here:
Ofcom | Self-help TV Relays and Digital Switchover
Maybe your MP would be able to help.
Is it really the case that hundreds cannot have dishes fitted? They could of course go above the roof-line on a pole, possibly on the chimney or if not, fitted to a side-wall with a mast.
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P. Kieran Ward: The EPG information for all Freeview channels is carried on all of them. Therefore if you are watching BBC, for example, the EPG information for ITV and Channel 4 will still be available.
Clearly it won't be available across the two platforms: Freeview and Saorview.
From what you describe, your receiver doesn't "take the initiative" and "look" for the EPG information on any other multiplex other than the one that it is currently tuned to.
I'm not a professional so don't know whether there is a way around this. On reading comments online, the Humax devices are well designed, so if they won't do it, then maybe nothing will do it.
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louis feather: At just over half a mile I would expect that the signal from the Idle transmitter will be plenty strong enough. If anything, your receiver could be suffering too high a signal level rather than too low a level.
Confirm that it is tuned to Idle for all signals and that you aren't watching the output of another transmitter such as Emley Moor. Do this by checking the signal strength screen whilst on each of the following:
BBC One=C24
ITV1=C21
BBC One HD (if HD model)=C27
ITV3=C42
Pick TV=C45
Film4=C39
Can you not see the transmitter from your house? With line-of-sight you certainly shouldn't be expected to have a problem.
Too high a signal level can overwhelm the receiver and as a result, it can start to indicate too low a signal level and poor quality. Sometimes this will cause the strength and quality meters to jump up and down.
See:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
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MEM: Because the DAB signal and the TV signal are different signals. The TV switchover didn't mean any difference to DAB radio.
See:
Digital Radio Ireland » Can I get DAB
Maybe you need a directional aerial.
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Adrian: Have you done a full reset?
I understand that the transmission power of CC went up at switchover, so could you have too high a signal level now? If so, this may likely show as too low a level or no signal.
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Frustrated new mover : That is odd. Have you identified the 7 rooms that it serves and are you sure that the room in question isn't one of them.
Do the dish feeds run from the loft or could one be fed from the loft? The cable used for satellite is ideal for Freeview as well, it is just the plug that might need changing or a suitable adaptor fitting.
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PETER HUGHES: In principle, the PSB network after switchover is the same as the former four-channel analogue (there may be odd exceptions).
The Commercial network (COM channels) fit in any space that is left. Even the transmitters that broadcast COMs, some viewers will only receive PSBs. See here for a projected chart:
The commercial multiplex after switchover: ArqA, ArqB and SDN | ukfree.tv - 10 years of independent, free digital TV advice
Looking at the bar for Sudbury, I would say they reckon about 80% will be able to receive PSBs+COMs and the other 20% will be PSB only.
The point therefore is that even if the Ceefax test is accurate, it can only be so for PSB channels.
I receive from Emley Moor where all six channels are at 174kW and are within Group B. On turning my aerial off-beam, the COMs are much more critical. The PSBs remain strong after the COMs have been lost.
I am not an expert in this field. However, the only thing I can think is that the COMs are more restricted (even if slightly). Perhaps the beam-tilt of the COMs from the radiating antenna array is lower than that of the PSBs. Thus the PSBs go further over the horizon than the COMs, as it were.
This would seem to be a sensible hypothesis because the channels used by the COMs are re-used by transmitters in closer proximity to those of the three PSB channels and this is common with COM channels from many (all?) transmitters.
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Mr t: In addition to what's already been said by KMJ, see:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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robert: You do not have to pay Sky to watch it via Freeview. You also do not have to pay Sky either.
It is a business decision as to which platform(s) each the channel wishes to go on.
As their objective is maximising revenue (profit) then perhaps the answer is that it is more worthwhile for the broadcaster to pay to be on Freeview *and* part of the subscription-based Sky service rather than just being on one or the other.
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d gould: The most common cause of such an issue is that the receiver has tuned to the wrong transmitter (i.e. the one which the aerial does not face and was installed for).
Therefore the first thing is to establish that you are watching the output of the correct transmitter.
At your location you may be able to receive from the main Crystal Palace transmitter and the Cane Hill relay. The former broadcasts all channels and is south south west with the aerial horizontal. The latter broadcasts only Public Service (PSB) channels and is north north east (the opposite direction of Crystal Palace) with the aerial vertical.
On each of the channels/services below, bring up the signal strength screen and observe which UHF channel it is tuned to.
The channels for Crystal Palace (CP) and Cane Hill (CH) are:
PSB1 | BBC One | CP=C23 | CH=C58
PSB2 | ITV1 | CP=C26 | CH=C49
PSB3 | BBC One HD | CP=C30 | CH=C54
COM4 | ITV3 | CP=C25
COM5 | Pick TV | CP=C22
COM6 | Film4 | CP=C28
If your aerial faces Cane Hill and has tuned in Crystal Palace PSBs, then run the automatic tuning scan through with the aerial unplugged for the first 50% to miss out scanning of CP channels. This should give you Cane Hill's PSBs with no COMs (Commercials).
If your aerial faces Crystal Palace and has tuned in Cane Hill's PSBs, then run the automatic tuning scan and unplug at 30% then plug in again when the scan has completed.
The small transmitters like Cane Hill do not broadcast COM channels because the Commercial broadcasters do not consider it worth their while to pay for them. As a result, anyone using them will not have the COMs (or may do poorly/intermittantly due to picking them up from another transmitter).
Some, such as yourself, may be able to change to using Crystal Palace to get the full service. Those who have no choice and who cannot receive from a full-service transmitter will only have PSB channels.
For a full list of Freeview channels by multiplex (PSB/COM), see:
DTG :: DTT Services by Multiplex
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d gould: I should add that Reigate "may" be a possibility to some degree and it is vertically polarised, as Cane Hill, and in the opposite direction. It is a full-service transmitter and its channels are:
60, 57, 53(HD), 21, 24, 27
If you have your aerial on Cane Hill, then you may be looking to switch to Crystal Palace. See ATV's site for lots of information and products:
Crystal Palace Transmitter
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Adrian miller: If you can see Carmel at 5 miles, then too much signal is a possibility, maybe driven OTT by the amplifier:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
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Felix valentine: Probably. You will need a Freeview HD reciever; RT/TG4 are in standard definition. They are broadcast from Black Mountain rather than Divis but it is only four degrees anti-clockwise from Divis, so, assuming no issues such as an obstruction, then the single aerial should be expected to work for both.
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Bryan: In addition to the response from KMJ,Derby, 4G signals will be vertically polarised. Your Sandy Heath aerial is horizontal so this is another factor which makes you even more less likely to be susceptible to problems with 4G interference.
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Joanne Lomas: The answer as to the cause may be due to the fact that the Bilsdale transmitter (which carries Tyne Tees/North East programming) uses lower channels/frequencies than Emley and is therefore picked up first during the scan. If, having done the scan, the receiver simply goes with the first it found, then maybe that explains why it goes with Bilsdale.
There is a simple way around it and that is to have the aerial lead unplugged for the first 30% of the scan so as to have it out for Bilsdale and in for Emley.
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Joanne Lomas: If, having tuned it to Emley Moor, you still have difficulty, then your receiver could perhaps be being overloaded due to too high a signal level brought about by its close proximity to the transmitter. See:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
It may also be worth checking that it is tuned to Emley Moor by viewing the signal strength screen whilst on each of the following and ensuring that the tuned UHF/RF channel number (frequency) is that of Emley:
PSB1 | BBC One | C47
PSB2 | ITV1 | C44
PSB3 | BBC One HD (if applicable) | C41
COM4 | ITV3 | C51
COM5 | Pick Tv | C52
COM6 | Film4 | C48
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gab: Please let us know your location, preferably in the form of postcode or nearby postcode (e.g. a shop) for the purposes of prediction of signal in your area.
Lots of information on aerials at www.aerialsandtv.com
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gab: I get the impression that you are in a very good signal area, in which case a log periodic (DM Log) should work fine (follow the link to ATV below).
The terrain plot suggests a good view of the transmitter at 12 miles:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
Obviously this does not take into account any obstructions such as trees or buildings which may adversely affect the signal.
A cursory look on Streetview shows most aerials to be regular size which tends to suggest that a log will be sufficient. (Obviously just because someone has a large high-gain aerial fitted doesn't necessarily mean that it is required.)
See:
Crystal Palace Transmitter
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graham : You could do, although it only broadcasts PSB channels. Thus, if the drop-outs affect only the COMs then you will be no better off.
For a full list of Freeview channels, including which are PSB and which are COM, see:
DTG :: DTT Services by Multiplex
The difficulty with Heathfield would appear to be the high ground in and around Awbrook. There are also a lot of trees around, including some which appear to be in the way of HH transmitter for some houses. This perhaps explains the use of higher gain aerials on some houses for HH.
If your HH aerial is a Group B one (yellow tip), then this is suitable for Heathfield, albeit that perhaps you need a higher gain one. Or then again, maybe it needs mounting higher up.
See:
Aerials, TV Aerial and Digital Aerial
Prior to switchover, Heathfield used Group C/D channels but now the COMs are below C/D and a B aerial should be used in cases where a Group aerial is used.
See here for more information about Heathfield:
Heathfield Transmitter
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graham: Check that your TV/box is tuned to the correct transmitter and that you aren't unwittingly watching the signals from a different transmitter. View the signal strength screen and check that the following are tuned to the right UHF channel:
BBC One C52
ITV1 C49
BBC One HD C47
ITV3 C42
Pick TV C44
Film4 C41
Haywards Heath's are 45, 46 and 43.
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ADRIAN: I don't think that doing a factory reset would revert you back to the later firmware (software).
Once you have exhausted all other avenues, then a factory reset would appear to be the only thing left.
What options you have depend on the design. In some cases it is possible to delete individual multiplexes or services. Or running the scan through with the aerial unplugged may "blank" the memory. Perhaps due to the fact that the channels are/were tuned in on C53 that some remnant of this still remains in the memory and is preventing the C52 mux from working. I don't know exactly how it works, so that is just my thought and possible explanation should it turn out that a full reset does the trick.
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Gary: Is this the device?
Sharman multiCOM Ltd. - ALTAI T103C 8-WAY AERIAL AMPLIFIER
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Alex: Mobile base stations are typically located within a few miles.
According to Ofcom Sitefinder, the Midhurst transmitting station is home to a 3 base station but it is only likely to serve you if you live within a few miles of it and probably that there isn't a closer 3 base station.
Ofcom Sitefinder shows the location of mobile phone base stations:
'Sitefinder' Mobile Phone Base Station Database
I seem to recall reading somewhere that not all operators keep it updated on where their base stations are, so it isn't forced to be a true picture.
Click on the map and then enter a location or postcode. Then zoom in or out. You need to be zoomed in so much to show the base stations which are blue pins. Click on one and it will show the operator(s)/network(s) at that location.
UMTS is 3G of which O2, Vodafone, Orange, T-Mobile and 3 have such networks.
This may allow you to work out where your local 3 base station(s) are (or were). This may be helpful in yielding an explanation. For example, if you find that there is one on the roof of a building that is now undergoing work, it could have perhaps necessitated it to be turned off. Or, having found out the location of the station, you may be able to observe some object that is now between you and it and therefore potentially acting to reduce the signal strength at your location.
As I say, it is "may" help yield an explanation.
Another possibility is that 3 has re-sited the local base station which isn't as good at your location as the previous one.
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anne hoey: OTA means "over the air".
Knowledge of the model number might be useful.
Perhaps it is an update to the firmware (in-built software), in which case knowledge of the model number would allow us to see whether an update for that model is being broadcast. Or perhaps your TV has tuned in signals from Moel y Parc transmitter in Wales. Early this morning one of its channels changed frequency, so maybe it is reacting to that.
These are just possible ideas. Did it stop after a while? If so, how long was it like that?
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Gary: It seems a bit of a coincidence that a different device from a different manufacturer would have the same model number. Perhaps it is the same device (the electronics inside) but in a different box.
In any case, try turning off the amplifier having checked to see what the strength is on the Freeview TV that is working. See if having the amp turned off reduces the strength. If it doesn't, then it certainly points to it being defective.
The other thing to try is connecting the incoming lead from the aerial onto the outgoing feed to the room with the TV in. This may require an adaptor if the two connectors are the same gender.
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VALERIE: Further to Nicholas Willmott's comment, I had wondered whether it was worth a shot at switching polarisation.
Rowridge transmits horizontally and vertically and has done so since switchover. Some channels aren't as strong horizontally, but this does not include those of the BBC which are PSBs.
I'm not an expert, but I wonder whether the affect of the trees may be different with vertical polarisation than horizontal polarisation. As you have consulted an aerial installer, I would expect that if this were worth trying that it would have been so.
Basically it means switching the aerial to vertical, so that its elements are up/down rather than flat. The PSB channels (BBC, ITV1, C4, C5 and some others) are at the same strength horizontally and vertically.
The COM channels (Pick TV, ITV3, Film4 etc) are lower power horizontally and the same power as the PSBs vertically. Thus, even without the issue with the trees it is best to use vertical polarisation (for Rowridge). The horizontal polarised signals are more for legacy purposes, i.e. so as to work with existing horizontally-mounted aerials.
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Lynne Robson: I came across this unofficial site which describes the issue:
Unofficial Vestel PVR Information (UK) - T825 Freeview+
This model is apparently a Vestel T825 model.
According the site, this is a known issue and there was an update to the firmware, although the note at the end says that some users have reported that the issue remains even after the update. The firmware is the in-built software, a bit like what Windows is to a PC.
I found the user manual here:
http://www.hitachiservice….pdf
Page 29, part 5.2.7 talks about "Receiver Upgrade" which can be accessed through the menu via Setup > Configuration. It often will say somewhere what version is installed, although the screen shot in the manual simply gives the date and time when the software was built.
According to the link I provided, the latest software is version 13.0. Even if there is no version number, perhaps the date will be a clue. The page dates back to 2010, so if, for example, your software is dated 2007 (maybe it is what was installed when the device was built), then this pre-dates the update and therefore suggests that it is running the old version.
Indeed, the page linked to gives the factory version for your model as 2.8, dated 2007-11-13 18:12:13.
When the manufacturers publish updates to firmware for their models, they have them broadcast over the air. In order for the devices to upgrade, they will have to be switched on and be set to do so. The manual says that it looks at 3am and that it will have to be set to do so.
If your firmware has not been updated, then the website has available what it says is the updated version. Obviously this is an unofficial site, so it is all at your own risk as the loading of corrupt/incorrect firmware could render the device useless.
Your model has a RS232 connection which means that it can be connected to a PC with such a port and upgraded with the appropriate firmware. This tends to be older machines and some desktops.
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Lynne Robson: The last sentence - it is older PCs that tend to have RS232 (serial) connections because USB is the most common way of connecting devices these days.
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mike: To put Briantist's statement into context, he was replying to Paul Weaire who said that he was using the TV, which is requires a licence. Most people who have one or more TVs use them and Mr Weaire said that he does. He also said that he was "reluctant to punish the BBC" by withholding his licence fee, but had "no other course of action". Use of TV equipment without a valid licence is against the law. Thus, only the illegally-acting viewer will be likely to be punished accordingly.
Mr Weaire has not made any subsequent posting to this site and was not asking for help; just reporting the issues he was having.
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Lorna knipe: See the Scheme's website The Switchover Help Scheme can help you make the switch to digital TV. | Switchover Help Scheme
Click on the map for your relation's region. Tyne Tees was the final UK mainland region to switch and this happened in September and it says that from 26 October 2012 the Scheme was closed in that region. Therefore I assume that in other mainland regions it will be unavailable.
The final region to switch was Northern Ireland (last month) and eligible people can apply there until 24 November 2012.
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gerry flanagan: Any you can get!
Basically it will be down to Divis or Brougher Mountain. Both use only Group A channels. Brougher's COMs are on very low power and co-channel with Divis' PSBs, so they are not at all likely.
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gerry flanagan: Wideband aerials have less gain on Group A channels. See:
Rowridge Transmitter
For that reason, there is no such thing as a High Gain wideband aerial for the A group frequencies, of which Divis uses exclusively. For that reason, the better bet, where a high-gain aerial is required, is to use a Group A high-gain aerial.
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Paul: At a guess I'd say that the reason is that Winter Hill is second behind Crystal Palace for the number of viewers served!
This would appear to be a story born from statistics.
The filter fits inline with the aerial lead to prevent the 4G signal (which is being picked up by the TV aerial) from reaching the TV receiver.
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Stan: The Waltham transmitter is undergoing engineering work and has been so for the last month. As a result, there is a warning of "possible weak signal".
Digital reception is pretty much all or nothing whereas analogue reception was analogous to signal strength. So with analogue you would have had a picture, albeit more grainy whereas with digital, there is a threshold over which the picture is there and below which it is not with a small bit inbetween where it may be iffy.
The channels have disappeared from your receiver because you have carried out a full retune. The first stage of this is to wipe what is stored.
Providing that the receiver is tuned to the correct transmitter, then there can be no improvement by retuning. The only outcome will either be the same or negative which is to loose the channels. Now you will have to repeatedly retune until they return and this will happen when the signal is stronger again. Had you left them as they were, all you would have had to do was change over to Film4, Yesterday etc.
If the receiver has manual tuning, then you can try that. For Film4 and Yesterday tune to UHF channel 57.
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anne: Tacolneston is undergoing engineering works and has been so for a while.
One possibility is that your receiver is tuning to another transmitter, so it is worth checking that this is not the case.
Once you have it tuned correctly, then don't retune, even if you have poor reception, because the issue is not the tuning and all you can achieve by this is either the same outcome (i.e. tuned the same) or lost channels (a backwards step).
Confirm that all channels are tuned to Tacolneston by bringing up the signal strength screen on each of the following on observing the UHF/RF channel number it is tuned to:
BBC One C55
ITV1 C59
BBC One HD (if applicable) C62
ITV3 C42
Pick TV C45
Film4 C50
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Paul Ketteridge: If you are receiving from Tacolneston or Waltham, then they are undergoing engineering work which may mean reduced signal strength.
Retuning is a waste of time as TVs store which frequency each signal is on and providing this is correct, retuning can't make the signal stronger!
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Gerry Flanagan: I agree with Charles here. As I said in my posting to you about Virginia: you have to go with what you can get.
I have read that the Kilkeel relay can be received along the east coast.
The coverage maps on this site (I assume) assume an omnidirectional radiation pattern due to the fact that the powers that be won't release the actual ones.
The BBC Wales map shows all transmitters in Wales:
BBC Wales | ukfree.tv - 10 years of independent, free digital TV advice
A map of the full service transmitters (which broadcast PSBs and COMs) is here:
Full service Freeview transmitters | ukfree.tv - 10 years of independent, free digital TV advice
I draw your attention to this because the full service transmitters are the higher-power ones:
Full service Freeview transmitters | ukfree.tv - 10 years of independent, free digital TV advice
Looking at the map, the main ones are:
Llandona
Blaenplwyf
Preseli
Arfon (2kW PSB-only relay)
UK transmitters, including channels and powers:
Ofcom | Digital Switchover Transmitter Details
(Not sure how up-to-date this is.).
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anne: Engineering work at Tacolneston which may mean weak signal and therefore interrupted viewing for some.
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frank ward: Predictors can never be entirely accurate. They certainly don't say what you "should" be able to receive.
The fact that you live on a slope could be an issue as it could mean that what can and cannot be received varies by property. And of course, being in a bungalow you are lower to the ground (I assume this to be the case having looked at Streetview). Looking at where others are receiving from may be a useful start.
By my reckoning, there are a number of aerials on Preseli which is in the direction that the land goes upwards.
Some aerials appear to be pointing at Huntshaw Cross (154 degrees, horizontally polarised). However this is across the Severn and therefore doesn't broadcast Welsh regional programming.
Then there are a few vertically polarised aerials pointing east which could be on Ferryside (83 degrees) or perhaps Kilvey Hill (104 degrees). The thing with Ferryside is that it is 15 miles away and is only a few watts, so anything less than line-of-sight won't work. Plus Greenhill is co-channel on 21 (BBC) and 24 (HD) which probably explains why Ferryside is at 25W for these whereas 30 (ITV1, C4 etc) is 5W.
Where does your aerial or aerials point?
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Margaret Quayle: Some of the transmitters in Wales had changes to some of their frequencies (UHF channels) in the early hours of Wednesday morning. This included PSB2 mux (ITV1, S4C, C4 etc) at Moel y Parc which is probably the Welsh transmitter you are using.
You may have to carry out a full retune, or you may be able to manually tune to the new channel number. Which it is depends on whether the design of your set allows.
First off, if there is manual tuning, try a tune to UHF channel 39 which is the new channel number. If this restores the missing channels, then you don't need to do anything else.
Or failing that, running the automatic tuning shouldn't affect settings such as brightness and contrast - it is generally a factory reset that does that.
What settings is it that you are concerned about being deleted?
If you are concerned that BBC One and Two Wales and ITV1 Wales will not end up in positions 1, 2 and 3, then there may be a workaround if the set chooses to put North West/Granada in those positions.
If you run the automatic tuning scan and unplug the aerial when it gets to 55% (or past C45 if it gives channel numbers whilst scanning) you will ensure that it doesn't pick up any signals from Winter Hill (North West/Granada) as these are picked up after that point. You will, however, have had the aerial in for scanning of Moel y Parc and this should have put its BBC and ITV in positions 1, 2 and 3.
Once you have done this, if your set has manual tuning, then the next bit is much easier. Add (via manual tune) the following:
- BBC North West from Winter Hill by tuning to channel 62
- ITV Granada from Winter Hill by tuning to channel 59
Now for the Commercial (COM) channels. See here for which services these are and for which multiplex (signal, e.g. COM5) they are carried on:
DTG :: DTT Services by Multiplex
I suggest that you focus in on the first service from each multiplex, i.e. ITV3 (COM4), Pick TV (COM5) and Film4 (COM6).
For COM4/SDN (ITV3 etc), manually tune to channel 58 for Winter Hill.
For COM5/ArqA (Pick TV etc), manually tune to channel 52 from Moel y Parc.
For COM6/ArqB (Film4 etc), manually tune to channel 55 from Winter Hill or channel 48 from Moel y Parc.
(The next two paragraphs are for information and so if you don't follow them, then don't worry.)
When providing the channel number for tuning in the COMs, I assume that your aerials are combined using a device called a diplexer which means that from your Moel y Parc aerial you receive channel 50 and below and that from your Winter Hill aerial you receive channel 52 and above. This means that anything from Winter Hill on C51 or below is unavailable and anything from Moel y Parc from C51 and above is unavailable.
Fortunately, what is unavailable from one transmitter is available from the other and for that reason, COM4 from Moel y Parc which is on C51 will probably be unavailable. Likewise, COM5 from Winter Hill although on C61 now (which is likely to be available to you), it will move to C49 in April which is why I didn't mention it.
If there is no manual tuning, then having run the scan through and unplugged at 55%, then select the tuning function along the lines of add new channels/services and have the aerial plugged in for all of that. It is important that you select the option to add new channels rather than the first time install as the objective is to pick up what wasn't picked up before.
You may have to dig through the 800s to find BBC One and Two from Winter Hill and ITV1 Granada, possibly swapping them for positions 800, 801 and 802 if the set allows.
You should be able to check which transmitter you are tuned to by viewing the signal strength screen:
For BBC One and Two it will say C45 for Moel y Parc and C62 for Winter Hill. For ITV1 Wales, S4C it will say C39 (from Moel y Parc) and for ITV1 Granada from Winter Hill it will say C59.
The others are:
COM4 Moel y Parc=C51 | Winter Hill=C58
COM5 Moel y Parc=C52 | Winter Hill=C61 (changes to C49 in April)
COM6 Moel y Parc=C48 | Winter Hill=C55
One final warning, and this is only if you have a diplexer as suggested above, then come April BBC One/Two from Winter Hill will move to C50 and this will therefore make it unavailable, or at least unreliable because it will be your Moel y Parc aerial that will be being used on this channel.
The only way around this, and it isn't forced to be a possibility, is if you can receive North West from Storeton transmitter instead of Winter Hill. This will require another aerial and another diplexer unfortunately.
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Patrick: Yes, there have been some channel changes. See:
You may have retune your Freeview equipment today in West and Southwest Wales | ukfree.tv - 10 years of independent, free digital TV advice
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Declan McGrath: These are carried on COM6 multiplex which is on channel 40 from Llandona.
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Alex: There are two possibilities I can think of (not an expert):
1. The base station you point your aerial at was turned off for a period.
2. The network decided to switch your connection to another base station.
As I say, I'm not an expert, so don't know how likely 2 is, but it would seem the only other explanation.
I take it that there was no obstruction such as a vehicle being parked in the way.
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kevin rose: Perhaps have Crystal Palace tuned in (probably in the 800s) as a back-up.
It is only 11 degrees off the bearing for Bluebell Hill.
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michael: I imagine that your RT aerial pointing in the general direction of Derry is directed at Holywell Hill, Co Donegal. Ensure that your receiver is tuned to it and not another RT transmitter; bring up the signal strength screen and ensure that it is tuned to UHF channel 30.
Limavady doesn't broadcast RT. This is because it was considered that across its service area there is sufficient overspill from the Republic's transmitters.
Whereabouts are you?
If Moville and Limavady are on roughly the same bearing, then you may get away with a single aerial directed somewhere between the two.
BTW, Moville broadcasts on C45, so if that is what you are tuned to, then that's where it's coming from.
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Helen: Are you saying that your main TV is picking up ITV1, C4 etc and that it is strong?
If there is a variable control on your distribution amplifier, then try turning it down so that the signal level indicated on the main TV isn't as high. Then try tuning in the others.
If the other TVs have manual tuning, then use it instead of running through the full tuning scan. If your aerial is directed to Mendip (horizontal, elements flat), then tune to C54. If your aerial is directed to Bath (vertical, elements up/down), then tune to C28.
The tuned TV will probably tell you whether it is tuned to 54 or 28 on the signal strength screen. This, of course, doesn't necessarily mean that it is tuned to correctly (which is to the transmitter to which the aerial faces). Should this be the case, then this requires correction.
For Bath where Mendip is being picked up, then unplug the aerial when the scan gets to 30%. For Mendip where Bath is being picked up, start the scan with the aerial unplugged and plug in at 50%.
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Michael Martin: Logical channel number (LCN) number 8 is used by Channel 4 from transmitters in Wales as it is displaced from LCN 4 by S4C.
Evidently after scanning all available signals, the two devices come to a different conclusion, possibly having made a different "decision".
Some older devices simply go with the first signals they find. Others go with the strongest. Whether either employ the former method is perhaps doubtful, but the point is that this is an example of why the results might differ.
The problem of receivers tuning in signals from other transmitters (i.e. any but which the aerial was installed to receive) was present in the days of analogue.
This is only a potential issue when the automatic tuning process is carried out. This may be when run by the user or due to the device running it automatically when unattended. It may be possible to disable the latter through the menu, although not all devices allow, a sure short-sightment in the design.
Running the automatic tuning scan with the aerial unplugged up until 55% should miss out scanning of Moel y Parc's PSB channels. The COMs are lower power and may therefore not be picked up.
You should be able to identify which transmitter you are watching by viewing the UHF channel number on the signal strength screen.
As you have clear line-of-sight to Winter Hill you clearly have a strong signal. You may be able to install an attenuator inline with the aerial lead to reduce the level of all signals. This may reduce the unwanted Moel y Parc signals sufficiently that they are not picked up (or certainly not placed in the main LCN positions) during the scan.
An example attenuator is (other suppliers and models are available):
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
Obviously if you have an amplifier then this should be reduced or even removed before you start attenuating. This is because an attenuator reduces the signal strength whereas an amplifier acts to increase it.
With digital reception the objective is not to get the strength as high as possible. There is a lower threshold over which the picture resolves perfectly (assuming good quality, i.e. digits not corrupted). There is an upper threshold over which the receiver becomes overwhelmed and quality goes. So reducing the signal strength won't make the picture worse, providing that it doesn't go below the lower threshold.
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John: I should imagine that your TV has tuned to Moel y Parc instead. Unfortunately The Wrekin's COM channels (ITV3, Pick TV, Film4 etc) are interleaved with Moel y Parc's PSBs (BBC, ITV1, S4C, C4 etc), so unplugging the aerial for Moel y Parc will miss out some of The Wrekin's channels.
If your receiver has manual tuning then run the automatic tuning scan through and unplug the aerial when it gets to 30% (or past UHF channel 30 if it gives channel numbers during the scan).
Once completed, plug the aerial in and manually tune in The Wrekin's three COM channels which are 41, 44, 47.
If you have a signal amplifier, then turn it down. The objective is to reduce all signals and hopefully reduce Moel y Parc enough that it doesn't get picked by your TV but not to reduce The Wrekin too much.
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John: The irony is that the retune on 14th November did not affect The Wrekin.
If you retuned as a result of being prompted to do so as a result of on-screen messages, then this must have come from the fact that your receiver had tuned one or more multiplexes from Moel y Parc, probably with them in the 800s, unless this was also broadcast across the Central region as well. The fact that you are receiving Moel y Parc now suggests that you probably received a message (if indeed there was such a message) from it.
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Pam: If your TV has a manual tuning function, then go to it and select/scan UHF channel 51.
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John Thompson: For ideas of a suitable aerial see:
Digital TV Transmitters
If you have a DIY aerial, then it will probably be a wideband yagi (black tip) which isn't as effective for Group A transmitters like Caldbeck, although you could try it.
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P. Kieran Ward: This any good?
BBC - Help receiving TV and radio - Satellite frequencies of BBC channels
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Hayley: It sounds like you might need to reconnect the "box". What does it say on it? Does it have a make and model number?
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morleyresident: No.
Do you have an amplifier that is bringing in the weaker signals from Waltham? If it is for distributing signals to different rooms, then turn it down. If your aerial serves just the one room and you have an amplifier, remove it.
The channels used by the two transmitters are:
29 Waltham COM4
41 Emley PSB3(HD)
44 Emley PSB2
47 Emley PSB1
48 Emley COM6
51 Emley COM4
52 Emley COM5
54 Waltham PSB2
56 Waltham COM5
57 Waltham COM6
58 Waltham PSB3(HD)
61 Waltham PSB1
PSB2 carries ITV1, ITV2, Channel 4, Channel 5 etc. PSB1 carries BBC standard definition.
Thus, if you have your aerial unplugged by C54 then you will have it out for scanning of Waltham's PSB channels.
With Emley's highest being on C52 there isn't much of a target window in which to unplug your aerial. With manual tuning it is much easier; unplug to ensure that you are out for C54 but which you know that you may miss out Emley's C52 and possibly C51. Then manually add C51 (ITV3 etc) and C52 (Pick TV etc).
The scan runs 21 to 69, so C53 is about 66%.
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morleyresident: The following is for if you don't have manual tuning but if you are having difficulty getting the aerial out after C52 but before C54.
If your receiver does not have manual tuning, but has two types of scan:
1. A full scan or "first-time" install, where it wipes all what's stored.
2. One to add new services/channels which doesn't wipe what is stored but just adds any new that are found, then you might use that to your advantage:
Run the number 1 type scan through with the aerial unplugged, plug in at 30%. Unplug at 58%. The objective of this is to pick up the PSBs from Emley. It doesn't matter if it picks up one of the COMs, the point is to get Emley's PSBs stored in their proper logical channel number (LCN) positions (i.e. 1=BBC One, 2=BBC Two).
Having done this, then run the scan to add new services (type 2) and have the aerial unplugged. Plug in at 50% and unplug at 67%. This time if you happen to have it plugged in for C54 then that will (hopefully) not assume LCN 1, 2 etc but go in the 800s because positions 1, 2 are already taken.
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P. Kieran Ward: I can't advise you much more as I've never used a satellite receiver before!
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Frank: I'm not familiar with the i-Can, but if it allows manual tuning, then tune to UHF channel 39. If there is a setting on the manual tune screen for DVB-T or DVB-T2, then ensure that the latter is selected.
It is a good idea to confirm that the receiver you have will receive RT channels so as not to have work done on your aerial if it isn't that that's at fault.
On the subject of aerials and the NI Mux (RT/TG4), there are two things to be aware of:
1. Like the former Channel 5 analogue signal, the NI Mux is broadcast from Black Mountain rather than Divis. For many people the two are on close enough bearings such that a single aerial will work for both. At your location Black Mountain is 5 degrees anti-clockwise of Divis.
2. The NI Mux is on C39 which is officially just outside of Group A. It is close enough that some aerial will work.
See this page which illustrates the point:
Gain (curves), Again
Along the bottom are UHF channel numbers (frequencies) and the Divis ones are from 21 to 29. The traces are just examples and may not be the same as that of your aerial.
However, the gain outside-of-group (C39 is outside of Group A) for contract aerials can be very inconsistent.
Group K goes further up than Group A, so if you have your aerial replaced, that might be the thing to go for. A wideband yagi aerial isn't really suited to Group A transmitters because the gain is lower on Group A channels.
If possible, I suggest that you see if you can get your receiver tuned to the NI Mux, perhaps by connecting it to your neighbour's aerial.
If it doesn't receive RT when you connect it to your aerial, then try turning it slightly anti-clockwise, observing the signal strength screen whilst on the tuned RT channel or whilst on manual tuning screen with C39 selected (and DVB-T2 mode selected if applicable). When you do this, if you don't press the button to scan/search the channel it will hopefully (as many do) give an indication of signal strength, which means that you can use it as a signal meter.
For information on aerials, see ATV's site:
ATV`s Choice Of Aerials for digital TV
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David Anderson: For Girvan transmitter your aerial should be vertical. It is on a bearing of 217 degrees, whereas Divis is at 229 degrees which is very close. That said, Divis is horizontally polarised.
If you are picking up BBC Northern Ireland on UHF channel 27 (look at the signal strength screen whilst on BBC One), then you are receiving it from Divis.
The Girvan transmitter uses high channel numbers and Divis uses low ones which will probably be found first during the scan. Have the aerial unplugged for the first 50% of the scan.
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Jacqueline Fowler: I posted an explanation here in response to Alan:
Bilsdale (North Yorkshire, England) full-Freeview transmitter | ukfree.tv - 10 years of independent, free digital TV advice
A number of other people have reported exactly the same issue.
First off, if your TV has manual tuning you should attempt to tune to the missing multiplex (a multiplex is a single signal that carries multiple services).
Go through to the manual tune function (if there is one) and tune to UHF/RF channel 46. The multiplex on C46 carries Dave, Pick TV and others.
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David Anderson: Failing that, manually tune to UHF channel 50 for BBC and 59 for STV, C4, C5 etc.
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Mal: Of course there is a reason!
THere is now a two-tier terrestrial transmitter network. About 90% of the population can receive all the channels but the other 8.5% who can receive terrestrial TV can only receive the Public Service channels because the Commercial broadcasters don't consider it worth their while to serve them.
See:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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Bethan Williams: If the box has a manual tune function, then you need to go through to it and enter UHF/RF channel 57 for BBC from Llanddona.
Go to ITV1 and bring up signal strength screen and it should say that it is tuned to C60 for Llanddona. If it's not, then let us know what number it is tuned to.
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Clamityjane: For The Wrekin, you will probably have needed to have your old Group A aerial installed for analogue replaced.
The COM channels (ITV3, ITV4, Film4 etc) are on lower power than the PSBs.
PSB1 (BBC standard definition) from The Wrekin is co-channel with Storeton. Also, PSB2 (ITV1, ITV2, Channel 4 etc) from The Wrekin is co-channel with Storeton. Storeton is vertically polarised, and I'm not sure whether that could affect you at your location.
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Patrick: Not likely.
Try manually tuning to UHF channel 47. If there is an option on the manual tuning screen for DVB-T or DVB-T2, then select the latter.
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davidwfaulkner: I should imagine that it was to do with the works at Tacolneston that have affected TV broadcasts.
I provided the frequencies for Manningtree and Peterborough because they appear as if they may be the next best ones as well as Wrotham.
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Matthew Butterfield: Yes.
Unless the mobile operator in question is broadcasting illegally on the 800MHz spectrum which hasn't yet been auction off! This is that which is closest to TV frequencies and therefore possibly a likely source of interference.
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Andrew Tegala: I don't understand the question.
If your aerial points to Hannington then it has been installed to pick up signals from Hannington. If you "should" do anything, then surely you should use your aerial as it was designed.
If you would prefer to watch London programming then clearly you would have to consult with the person or body responsible for the aerial system although it would mean that everyone else in the block will also have change their regional programming unless a second aerial is fitted in order to give viewers choice.
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amanda: 1. I would try it and see. You may find that your current aerial works.
2. Yes.
3. No! A satellite dish points to a satellite which is in geostationary orbit above the earth whereas Heathfield is on the ground, albeit that the transmitting aerials are 300m off the ground.
If you have difficulty with any signals if you have a Group C/D aerial, then it will be the COM channels which are:
- COM4 (ITV3 etc) on UHF channel 42
- COM5 (Pick TV etc) on UHF channel 44
- COM6 (Film4 etc) on UHF channel 41
See here:
Aerials, TV Aerial and Digital Aerial
A Group C/D aerial is most sensitive on frequencies within the top third of the TV band and has a green tip. Previously Heathfield used C/D channels only and therefore a C/D aerial may be fitted.
After switchover, the COM channels are lower down in the middle third of frequencies used for TV which is Group B. However, due to your close proximity you may find that (if you have a C/D aerial) that it will still be sensitive enough to receive those channels.
If the feed from the aerial is split using a powered booster/amplifier and it has a variable control on, you may find that increasing it a bit will bring in the other channels.
Failing that, if you get a new aerial it doesn't have to be a wideband one. See here:
Heathfield Transmitter
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Frank: I responded to your posting on Monday:
Divis full-Freeview transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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g allonby: It could be if it is on the line between the transmitter and receiving aerial.
I believe that the operator has a responsibility to put the issue right. The predictor suggests that you might be able to receive the full-service from Pendle Forest as well as Winter Hill, so this may be a possibility.
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Vic: If you are using a communal aerial system it might need adjustment to allow the new frequency through from the aerial.
If your receiver has a manual tune function, then scan UHF/RF channel 39 for the missing services.
Failing that, perhaps a factory reset, or some sort of reset that you haven't yet carried out as yet. The thinking is that maybe the device has somehow "remembered" something of the old ITV multiplex on its old channel and so now doesn't (for whatever reason) recognise the new one.
Maybe you could share with us what the make and model of the device is as it might help others with the same issue.
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joanna carney: Perth is in a valley which means that it can't "see" the Angus transmitter near Dundee.
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Damian Cooper: Be aware that the Kilkeel relay also uses vertically.
We don't know what direction they it transmits as the powers that be won't release its radiation pattern. My guess is that it will be transmitting in the direction of Kilkeel and further up the coast to Ballymartin and Annalong. I should imagine that there is little point in it transmitting over the hills and so maybe it only broadcasts roughly between 3 o'clock and 6 o'clock
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Damian Cooper: Kilkeel also uses C39, although I'm not convinced that it will be an issue for you, although keep it in mind because you never know.
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mrdtv: The diplexer that splits at C51 will attenuate C52 about 4dB. This might not be an issue if the signal is sufficiently strong or if there is an amplifier, it might be sufficient or be able to be turned up a bit to compensate.
Online TV Splitters, Amps & Diplexers sales
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Joe Faulkner : The COM channels don't have as good a coverage as the PSBs. 1,000 or so small relays don't broadcast them, and those that do broadcast them don't spread them as widely as they do for their PSBs. The COM channels are re-used by transmitters in closer proximity than the PSBs and this appears as if it might be the case at your location.
The COMs from Darvel, Divis and Caldbeck are all co-channel and at half-power to their respective PSBs. The Digital UK Postcode checker even "thinks" Divis is the best transmitter for you. This suggests that the possibility of reception of Darvel COMs is limited by interference rather than limited because it doesn't carry as far.
For this reason, I don't think that you will be able to receive COMs from Darvel. The PSBs of Darvel and Divis are not co-channel.
If you can receive PSBs from Girvan which is 20 miles away and are at only 50W, then you may be able to turn your high-gain Group A aerial to Divis and combine with a Girvan aerial to give you BBC Scotland/STV regional output and COMs.
The only warning I will give you is that recorders can have difficulty with timed recordings when receiving from two different transmitter regions, the reason being that the EPG information isn't shared between the two. If this turns out to be the case then you will have to decide whether to have your recorder on one or the other (i.e. Girvan PSBs only or Divis PSBs+COMs).
If you can receive from Girvan, then you will need a diplexer to combine feeds:
Online TV Splitters, Amps & Diplexers sales
Girvan uses 50, 59 and 55 so the model that "splits" at C38 will be best. This will also allow reception of Divis PSBs as all its channels are below 38.
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Christine Ratcliffe: You would appear to be receiving from Waltham rather than Nottingham. Waltham is undergoing engineering works which may affect signals. You may or may not have been suffering poor reception for a longer period.
Winter Hill also broadcasts high power on UHF channel 61, although I'm not so sure that it might be the cause of your woes.
The terrain plot shows that the path between the transmitter and you is close to the ground for the final few miles which could be a source of issue:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
I see that other houses in the area have tall masts and large aerials which are probably a sign.
I'm not an installer, so the professionals may be able to add to what I'm saying.
Refer to the plot and imagine that the signal line is a light. With the path being close to the ground, objects such as trees and buildings could potentially be in the way. You know what happens when it gets near the end of daylight and the sun is low in the sky which causes long shadows.
Intermittent problematic reception caused by such reception can affect only one or two frequencies. Moving the aerial may be the only way - it is a try it and see thing I believe.
The only other thing I can wonder (as I say, I'm not a professional) is whether because your aerial is looking over your roof-top with the chimney not being immediately in front, but perhaps at 30 or 40 degrees to the direction the aerial is facing is whether when these get wet that they cause reflections such that it degrades the BBC frequency.
I note on Streetview that your roof tiles were replaced in 2009. I don't know whether that might have any bearing, e.g. whether newer tiles are more likely to be reflective, perhaps helped by them being wet.
"If" any of these (roof tiles or something else on your roof) is the cause of the issue, then perhaps mounting the aerial on the gable end that faces the transmitter. I say "if" because it could be some effect (reflection or refraction) that occurs further away from you such as if vegetation is in the way, and for that the solution is much more difficult.
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Graham: There's no such thing as a "digital" or "analogue" aerial. An aerial is an aerial.
For Belmont, the four analogue channels were in Group A (bottom third) and consequently Group A aerials may have been fitted. COM5 (Pick TV etc) and COM6 (Film4, Russia Today etc) are high up in C/D (top third of channels).
This terrain plot shows the drop you live in:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
If the "analog" (sic) aerial is a Group A one and you are receiving COM5 and COM6 fine, then that must tell you something. It is less sensitive and less directional on those higher channels and they are picked up fine.
A higher gain aerial is so because there is a narrower acceptance angle. That is, if you used it to transmit (send out a signal), the beam width would be narrower.
When you can see the transmitter, or aren't far off, then such an aerial can be focused on the beam from the transmitter. Maybe the issue you have is that your "big" aerial has too narrow an acceptance angle. Or alternatively, maybe it is situated in a dead spot.
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Dave: If that is the impact that it may have on TV reception, what might be the affect to the health of those living in such fields?
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George: If you are "practically on top of the mast" then WHY ON EARTH have you got a high gain aerial and a mast head amplifier???!!!!
Surely you would not need any let alone one!!
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
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Judy: I can't say for definate, but the retune on Wednesday obviously meant that the service was interrupted.
Perhaps the message you've quoted relates to that change and not some other work that is to be carried out but refers to the whole week rather than the day of the change.
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George: I'm surprised that at your location, even before switchover, you would have needed anything but a regular-sized aerial. I'm not a professional though.
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Graham: I think that if you intend to have another aerial installed, then it would be best to consult with an installer because yours is not a good area for reception.
The other possibility, and you may be able to DIY it, is to use the older aerial that gives you all the channels and fit a distribution amplifier to supply signals to multiple rooms.
I am not a professional myself so wouldn't like to advise what to use, but instead I can direct you to sources of information.
The website of ATV Sheffield holds a wealth of information on aerials and TV reception. Even they say that reception is a black art and presumably none more so in locations such as yours at the bottom of a drop, the sloping road and where there appears as if there are trees in the way for at least some on your road.
See:
Belmont TV Transmitter
Aerials, TV Aerial and Digital Aerial
Television Aerial Boosters / Amplifiers, Splitters, Diplexers & Triplexers
Gain comes at the expense of "loss" elsewhere. Where there is a beam to focus on (i.e. where you can see the transmitter), then this might be good. But the more you get away from that, the more it may be a disadvantage.
The COM channels do not have as good a coverage as the PSBs, and so some viewers, including those who use Belmont, will only receive PSBs, or may receive COM4 but not COM5 and COM6. The reason for this is that the channels that they use are reused in closer proximity than PSB channels.
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kevin rowbotham: I've written the answer here:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
The Licence fee goes to the BBC and, as a Public Service Broadcaster, you have the BBC.
The Commercial broadcasters have decided not to transmit from the small (few viewers) transmitters.
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Valerie Norris: I imagine that you might be receiving from Waltham which is undergoing engineering works which means bouts of low power.
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Dave Wilson: Anyone who suggests that you might be able to receive from Rosneath at your location must surely have been supping something!
See the terrain plot:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
Whilst it is only 9 miles from you, Bromley Muir is 80m above the top of the transmitter and you live 300m at the bottom on the other side!
Darvel is 30 miles away but there is also high ground in the way:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
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pam: Looking at Streetview, the houses I can see on your road have their aerials pointing to Rowridge.
If yours is the same, then have the aerial switched for vertical polarisation so as to take advantage of the stronger vertical COM signals (which carry the channels you're having difficulty with).
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martin: As KMJ,Derby says, this is usually caused by the memory being fulled and not enough to store the channels that are forgotten.
BBC from Winter Hill is on the highest channel (frequency). All of the transmitter's channels are at the top end of the group of frequencies used for TV. As a result, it could be that your box is storing the signals from other transmitters, by which time it comes to store your desired one there isn't enough memory.
The answer is usually to prevent it from filling the memory with some other signals. Have the aerial lead unplugged for the first 50% of the scan.
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David: I bought a new CRT television around 2004. I did look to see if there were any with digital tuners in-built but there weren't. In order to use the said set, I now must use a separate tuner.
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Up until now, BBC, as a Public Service Broadcaster and recipient of the Licence fee has carried all its services from all transmitters. This is a departure from that "universal" coverage principle.
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Dennis: Those in Canterbury, and indeed anywhere, can receive the full collection of Freeview channels "if" they can receive from one of the 81 full-service transmitters.
See the explanatio I wrote here:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
In some cases, those receiving from a relay such as Chartham find that they can, with a replacement aerial, receive the full service from one of those 81 transmitters.
It might be worth looking around your area to see what those around you are doing. Can you see any aerials pointing to Dover?
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Kathryn: Without giving your location (and possibly the transmitter you are using) it is impossible to even suggest an answer to such a question.
There engineering works at some transmitters which have resulted in poor or lost channels for some people. I know that Tacolneston is such a station.
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Ray Styles: For Freeview (terrestrial television) you only need one cable for which you can view as many channels simulataneously as you wish.
For satellite (Freesat, Sky etc) you need one cable for each channel you wish to view. So for a recorder with two feeds you can receive two channels simulataneously.
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Mike Potter: Refer to:
Digital UK - Planned Engineering Works
Quite a few digital relay transmitters, including Langholm, are subject to "service shutdowns" over this week.
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Martin Lucas: Each channel number has a frequency in MHz and these are shown on the transmitter page, so follow the link to Sutton Coldfield.
Belper has its own transmitter (again, click the word Belper to see its frequencies) so you could always be tuned to that instead. It uses higher channels so you may be able to avoid it by unplugging the aerial near the end of the scan.
Belper is a relay of Waltham and therefore provides East Midlands programming.
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David Campbell: Are you sure that you are receiving RT from Carnmoney Hill and not Clermont Carn?
Select one of the RT channels and bring up the signal strength screen. Carnmoney Hill is on C48 and Clermont Carn is on C52.
Both Clermont Carn and Carnmoney Hill are vertically polarised and I believe that the bearings from your location aren't too far apart.
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Malcolm: I have read your follow-up posting where you said that you tried manually tuning with no joy:
An update | ukfree.tv - 10 years of independent, free digital TV advice
The Streetview photo of your building shows the aerial on the roof clearly facing Heathfield, and so the Eastbourne relay plays no part in your reception.
Up until switchover, the lowest UHF channel (frequency) used in the 40s was 47. Your aerial system may be filtered to only allow particular channels or a particular range of channels. Now that the lower 40s are in use, and the lowest one is the one you can't receive, I wonder if it is your aerial system which needs some adjustment.
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Michael Cooney: The coverage map does not show what "should" and "should not" be possible to receive.
It is an indication of where the signal is calculated as being at or above a particular level at a particular height above ground. This does not mean that below that level that reception will not be possible. It could also be the case that the height a few CMs above that which is calculated is at or above the level.
The obvious thing to try is tuning in the problematic TV on one of your other aerials.
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Robert Fairbrother: Indeed. Even better, the issue "really ought" not to happen in the first place.
This is the nature of engineering work of any nature; it is usually impractical to give a timetable of the prospective turning of every screw. One assumes that the periods of low power and outages are kept to a minimum.
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Niall Burns: Divis uses only Group A channels, so use a Group A aerial rather than a wideband one which isn't as efficient for Group A channels:
Digital TV Transmitters
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John McGovern: The UK now has a two-tier terrestrial television transmitter network. This has been the case where 8.5% of the population who can receive Freeview can only receive the Public Service Broadcaster (PSB) channels.
The Commercial (COM) broadcasters have no obligation to provide a Public Service and only broadcast from 81 transmitters serving 90% of the population.
See here for a more in-depth explanation:
Londonderry transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Of those transmitters that do broadcast the COM channels (which carry ITV3 and ITV4), quite a few aren't as strong as their PSB signals. Hence there will be some who can only receive PSBs from these full-service transmitters.
The question is, which transmitter does your aerial face?
The Penryn relay is PSB-only and is adjacent to Budcock Hospital. It is on a bearing of 155 degrees and aerials for it are vertical.
The photos on Streetview show quite a few aerials pointing to Caradon Hill which is 38 miles away. It is on a bearing of 53 degrees and aerials are horizontal.
A few aerials face Redruth which is only 6.4 miles away, but which you live immediately at the bottom of a 80m drop. Aerials are horizontal and on a bearing of 297 degrees.
Caradon Hill and Redruth are full-service transmitters. If your aerial faces either then it is worth trying to manually tune missing channels.
There are three COM channels (signals) and each carries a number of services. ITV3 is on COM4. Also check to see if you have 11:Pick TV (COM5) and 15:Film4 (COM6)
The full list of Freeview services is here:
DTG :: DTT Services by Multiplex
You may be lucky and either be able to manually tune in the missing channels (perhaps doubtful as generally speaking we would expect them to be tuned during the automatic tuning sequence) or you may be able to replace your aerial with one that is sufficient to receive the COM channels.
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Channels for the two transmitters are:
Caradon Hill:
- COM4 = C21
- COM5 = C24
- COM6 = C27
Redruth:
- COM4 = C48
- COM5 = C52
- COM6 = C51
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Peter Henderson: The Streetview photos were taken in 2008 before switchover. I think that we can safely say that the pre-switchover digital signals would not have been available at Niall's location. It is perhaps also highly doubtful that the Black Mountain analogue Channel 5 signal would also have been available. So even if the four analogue channels could have been received from Divis, then this would have provided nothing extra over that of Newcastle.
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niall burns: I have had a few thoughts:
Can you see the top of the Newcastle transmitter tower (where the radiating antennas are situated) or are they obscured by Tollymore Forest? If they are behind the trees, then this could be a cause of poor reception. How did you fare for analogue? Was the picture changing such as during high winds? This might be an indication to the effects of the trees being in the path.
If you are receiving Clermont Carn and Newcastle you will be unable to combine the feeds using a diplexer due to the channels that each transmitter uses. If you have the feeds combined using a splitter in reverse, then, whilst it can work, results can be unpredictable and could therefore be a source of poor reception on one or both transmitters - try removing it and tuning to Newcastle without Clermont Carn connected.
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niall burns: In answer to your original question of whether reception from Divis is possible, it isn't possible to provide an exact answer.
It might be worth looking around to see what others have done. In Dundrinne Gardens there are (November 2008) some Divis aerials.
It appears as if Slievenaslat and Castlewellan Forest might be the difficulty in your area, although this is just based on looking at a map.
Digital UK Postcode Checker doesn't reckon Divis is a possibility, although such predictors are in no way infallible and it should therefore be taken with a pinch of salt.
It may be that satellite reception is the best option. There are solutions that allow reception of Freesat and Saorsat using a larger dish and two LNBs. Can't really advise more than that; try searching the internet for information.
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Adam: Without knowledge of your location so as to get an idea of predicted coverage it is impossible to answer such a question. A postcode or that of a nearby location such as a shop might be useful.
You should check to see that it is tuned to the correct transmitter (the one which the aerial faces) and not that of another transmitter. The issue could also be caused by too high a signal level which is generally a possible issue for those living close to a transmitter, and particularly so for high power ones.
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Mike Smith: Because there are only a handful of ITV1 HD regions. This is so as to not need equipment to produce HD feeds for each region or sub-region.
I'm not familiar with whether the regions that do have HD feeds produce their local news in HD.
Those regions that don't have counterpart HD feeds (such as ITV Meridian Southampton) we assume don't produce content in HD. Therefore if ITV were to change to having different regional feeds there would be no variance in the HD content available; local news would still be in standard definition.
BBC One HD does not broadcast regional news due to the same cost reasons.
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niall burns: You should confirm that you are tuned to Newcastle transmitter by viewing the signal strength screen. On BBC One it should be tuned to C50, UTV is C55 and BBC One HD is C59.
Is it all three of these channels that are playing up?
Perhaps it could be a possibility (800W @ 3.7miles) that the signal level is too high going into your receiver. This can appear as too little or too poor a signal:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
If you have an amplifier then it might be worth trying removing or turning it down. Or you might need some attenuation (the opposite of amplification).
The former analogue signals from Newcastle were at 1,000W each. The power of digital signals to serve the same area are -7dB of the analogue which is 200W.
The power of the signals now are 800W each which is -1dB on the analogue. So in real terms the signal is stronger than the former analogue.
You might be able to build a crude attenuator (prior to getting a proper one) by connecting only the inner core of the aerial lead by leaving the screen disconnected for a short distance (a few CM maybe). This will hopefully "loose" some signal.
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Tuesday 30 October 2012 1:02PM
Brendan: Quite a few transmitters that carry the Commercial (COM) channels have them at lower power than the Public Service (PSB) ones (usually half-power).