All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Stuart heynes: This is a bit of a riddle as I can't understand what the problem is.
There are a number of possibilities:
1. If you've retuned the TVs, then perhaps you've only retuned the digital side of them. Having reset them, maybe it wiped the memory for analogue channels. What each does probably varies by design.
The objective of this first stage is to tune the TVs to the Sky box. Don't change the RF out channel on the Sky box.
What I would do is put the Sky box on analogue programme number 1 on each of the TVs. That is where you used to have BBC One analogue.
2. There is the possibility that one of the new digital signals in your area use C44 or adjacent channels which now makes it unuseable and therefore you will have to change the RF out on your Sky box.
You have asked about retuning the Sky box, so I am wondering if you have carried out number 1 above.
Without knowing where you are, it isn't possible to work out whether this might be the case and which channel might be a good replacement.
I presume that the aerial feeds into the Sky box and then back out again to the other TVs. If there is a digital (Freeview) signal now on C44, this will cause interference on the analogue picture, as you might expect; it will appear grainy.
Try removing the incoming aerial lead to the Sky box. Then have the Sky box powered on and go to one of your TVs and attempt to tune in the analogue part. If there is manual tuning, then tune to C44. You may also look to see if the Sky box is still stored on the TV (in the analogue part), e.g. on number 6. Having got the output of the Sky box on the screen (via the RF feed), go back to the Sky box and plug the incoming aerial lead in. If plugging the lead in causes the picture to go grainy then you know that their is a digital signal coming down the aerial lead on C44 (or adjacent channels). If this is the case, then provide your location, preferably in the form of a post code or nearby post code (e.g. a shop) and we will see if we can work out what channel might be best for you to use.
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Alex D: I assume that you are picking up Moel y Parc, for which BBC is on C45 and ITV Wales/S4C is on C49.
Run the automatic tuning scan with the aerial lead unplugged up to C53 (if it gives channel numbers during the scan) or 66%. This should miss out Moel y Parc channels.
If you don't get it in in time, you may have to manually add Winter Hill channels:
C54 BBCB (HD, if applicable)
C55 ArqB (Yesterday etc)
C58 SDN/ITV3 etc
C59 D3&4 (ITV1 etc)
If you find that the thing decides to retune when unattended, then see if there is an option to stop it doing so. Indeed, as a matter of course it might be a good idea to disable such a "feature" as it would appear to be a nuisance. There isn't forced to be an option to disable it and if does turn out that it retunes at will, then cross that bridge when you get to it.
There are two possibilities that spring to mind:
1. An attenuator to reduce all signals with the hope that the Moel y Parc one is weaker and will, with sufficient attenuation, become so faint that the receiver doesn't use it.
2. A filter to only allow Group C/D channels through (C48 to C68). I'm not sure how effective this might be. Whilst it will reduce C48 a bit (owing to the fact that it's near its cut-off), ITV/S4C from Moel y Parc is on C49. It also uses C51 and C52 for two of the Commercial multiplexes, although they are lower power than the Public Service channels so may be less likely to be picked up.
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matt: All channels that were broadcasting before are broadcasting now. Without saying which are missing, how might we offer an explanation and a possible fix?
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Andrew Walter: The BBC channels from Dover on C50 are as they will be after 27th. That is, they have "switched". Obviously check that they are coming in on C50 and not another channel which would indicate that your receiver is tuned elsewhere which would therefore be the problem.
At under 3 miles from the 80kW transmitter your receiver could be being overwhelmed by the strength of the signal. Therefore this could get worse when all the other channels go up to full power.
You may need to get yourself an attenuator:
ukfree.tv - independent free digital TV advice
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Colin: Obviously try the "existing" aerial vertically. Indeed, whilst there is perhaps nothing lost to try it horizontally, be mindful that vertically is expected to be better.
Could you receive digital before switchover?
Did you have to wait until 18th April to receive the Commercial channels?
I'm not a professional aerial installer, but I use a loft aerial. It was sufficient to get solid reception on all channels before switchover.
However, after switchover I found that my Sony RDR-HXD870 froze for a few seconds every 15 or 30 minutes on the worst affected channels. With two other receivers connected to the same aerial as well, all tuned to the same channel, the others were solid and the Sony continued with occasional freezing.
I moved the aerial down the loft and replaced it and the problem continued. It was mounted on the L shaped bracket on one of the rafters.
The solution was to use a straight pole and mount it on the top of one of the joists so as to allow 2 or 3 feet between the back of the aerial and the sloping roof. Previously it was more like a foot with the L pole.
There is another loft aerial, which appears to be a shorter Philex SLx model to the one you have. This works solid even though it is also mounted with its rear within a foot of the rafters and felt. It has a massive reflector on the rear so I can only conclude that it screens against whatever the roof does to affect the signal.
Obviously different roof types affect the signal in different ways. Also the direction to the transmitter probably plays a part.
You might try sloping it upwards a bit, with the thinking that the signal is "sort of" coming from above.
I would be looking to test whether it may be too much signal. I tried this with my own problem and it didn't make a scrap of difference, although I'm 25 miles from the transmitter so it's not likely to be the cause.
Try connecting the lead to the TV with only the centre conductor connected. So strip back the screening and put the centre core into the centre of the TV's aerial socket. Then see what you get on C28. It's crude but it should hopefully "loose" some signal if this is your problem.
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Karen Furley: The rest of the channels come on 27th of this month.
That's the good news. There's two "buts"...
1. ...But "HD Ready" means that the set will not receive HD programmes over the air (via Freeview). I don't know whether you're aware of this as it catches a lot of people out (and which is probably why the marketeers like the phrase). All it means is that the TV can show HD pictures, but that they must come from another source, usually a set-top box.
2. ...But you may or may not be able to receive the full complement of Freeview channels.
The Public Service Broadcaster (PSB) channels are BBC, ITV1, ITV1+1, ITV2, Channel 4, Channel 4+1, E4, More 4, Channel 5 and the four HD channels. The rest are the Commercial (or "COM") broadcasters and they include ITV3, Pick TV, Yesterday, Film 4, Dave and many others.
If your aerial is directed to the Elham relay transmitter then you should be aware that it will carry only PSB channels. The aerial will be pointing north-easterly and will be vertical (elements up/down).
If your aerial is directed to the Dover transmitter, then you may be able to receive the COMs (it transmits PSBs and COMs). Dover is a little clockwise of east and your aerial will be horizontal.
The COMs cover 90% of the population whereas the PSBs cover about 98.5% of the population. The reason for the difference being that the COMs work on a profit-making basis selling advertising to show to viewers which they wish to aquire at lowest cost to themselves.
The COMs broadcast from the 81 largest (by viewer population) and achieve their 90% coverage. There are nearly 1,100 small "filler-in" transmitters like Elham and the cost for them to transmit from these is roughly equal to the amount it costs them for the 81 they have. When considered that the relays would only add 8.5% population to the potential viewer-base, it's not surprising that they're not interested.
The PSBs have a "Public Service" obligation, as the name implies, and the COMs don't.
The other main free-to-air service is Freesat and this may be particularly attractive for those not able to receive the Freeview COMs.
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Algernon Black: You haven't provided a link to the said page.
As a test, I entered the post code of The Sherborne Arms into the Digital UK Tradeview predictor:
Postcode Checker - Trade View
The retune in October of next year is because SDN is moving from C62 to C50. At this location the predictor considers the current channel "good" and the future channel "variable".
The predictor, as with any predictor, in no way suggests that anyone "will" or "will not" receive anything. It should merely be taken as a guide, being mindful that there are many many variables, not least that a post code is a massive space where signals vary and of course the fact that Royal Mail does not deliver television signals.
All I would suspect here is that C50 is used by another transmitter and that it has calculated that it may act to degrade reception. That does not mean that it will.
I wouldn't be concerned about what the predictor says; I would just be mindful of it. What matters is what actually happens.
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Simon Holland: Without knowing your location it is impossible have much of a chance of shedding light on the problem.
Not all transmitters carry all channels, Yesterday and other Commercial ones having restricted coverage. The fact that you picked it up one day and not another could be as a result of the fact that the transmitter that your aerial is directed to not broadcasting it.
What's your location, preferably in the form of post code or nearby post code (e.g. a shop)? What transmitter are you using or which direction does your aerial point if you do not know which transmitter it is directed to?
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Carol Golding: It is impossible to give a very specific answer as to what to try without knowledge of your location so as the likelihood of reception may be checked upon.
The thing that springs to mind here is that it would probably be better to extend the fixed roof-top aerial that you have (if you have one) to serve the "den" as well. This would irradicate any intermittant reception, as set-top aerials really aren't the best as they are in an environment where the signal isn't the best.
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Wednesday 13 June 2012 11:46PM
Andy: Read my posting above to Micky which I made at 3:31PM today!
COM4 remains on low power until 27th of this month.