All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
Therese: If you had reliable reception before switchover, the most likely explanation is that you now have too much signal. If you have a booster or amplifier, you should remove it. If not, or removing it doesn't help, try adding an attenuator.
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ALL: A common problem is that, if signal levels were already on the high side before switchover, the new signal levels are too high and cause distortion. Some boxes will not be able to read the distorted signal level properly and report a lower signal level. You will often get picture and sound break-up and in the worst cases the multiplex will not be decodable.
If you have a booster or amplifier, you should remove it or turn it down. In some cases you may have fitted, or had fitted, a new aerial with too much gain - in this case, add an attenuator. If you're using a communal aerial, your landlord or agent should be ensuring that the levels entering your property are appropriate.
The new multiplex is definitely running at the final power level - if it were not, the relays would not be able to receive it in order to retransmit it.
Another common problem is old onDigital/ITV Digital or early Freeview equipment that cannot handle the 8K mode used after switchover. Check if it's on the list at http://www.digitaluk.co.uk/2kequipment . It also might not be able to handle the larger Network Information Table in use since 2008 - see http://www.digitaluk.co.uk/splitnit . These lists are not complete, there may be other affected equipment not on them.
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Samir: If your analogue reception has also deteriorated, that would imply a general reduction in signal levels or increase in interference or noise. Start by checking that the aerial is intact and still pointing in the correct direction. Look for any new obstructions in the path, for example cranes or new buildings, or trees coming into leaf.
Cable damage is another cause of reception problems. In wet weather, damaged outer insulation can allow water to get into the cable, which changes its properties increasing the amount of signal lost in the cable. The place where the cable connects to the aerial should be waterproofed but that can also leak and allow water into the cable.
If the cable can freely move over tiles or walls, the outer insulation may wear through and allow the screening to be damaged. It should be securely anchored as it passes over tiles and brickwork. The insulation is also affected by UV light from the sun and does have a limited lifespan.
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Gavin: FreeVIEW TVs need to be connected to a UHF aerial, not to a satellite dish. There are FreeSAT TVs that expect to be connected to a dish.
Freeview TV aerial connectors just push in to the set or box, whereas satellite connections are threaded. Some aerial installers use threaded connections throughout, only converting to a plain connection for the last cable, because the threaded connections are generally more reliable, so you might have the other sort of connection.
If it is a Freeview TV, as you're fairly close to the Sandy Heath transmitter, you may pick up enough signal just in the cables. Different sets have different sensitivity - minimum signal requirement - so that could be why one works and another doesn't, or that the different lengths of cable produce different results.
It is possible to combine aerial and satellite dish signals onto the same cable (a diplexer) and to split them again at the other end. The signals from dish to box are at a higher frequencies than the signals from aerial to TV, so you can actually plug the combined connection into either device and it should work, if this has been done.
If you have an aerial and Freeview worked reliably before mid-April, you may have too much signal. If there's an amplifier or booster in the system, remove it or turn it down. If that doesn't help, add an attenuator.
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kmurray: We really need a full postcode to offer much advice. Different equipment has different minimum signal requirements, so that can explain why some services work and some don't. Also, the 'loop-through' connection from the box to the TV often introduces extra noise or additional unwanted gain - you might get better results by using a 'Y' splitter to feed each box from the same aerial cable, rather than connecting the TV to the box.
The 'fly lead' supplied for connecting the box to the TV is often poor quality. See Online Satellite/TV/FM/DAB Cable, Leads and Connectors sales. for a better quality replacement. A poor quality lead will drop more signal and pick up more noise.
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Bill: The help scheme offer an aerial replacement if necessary. If reception through an aerial is really not possible, or prohibitively expensive, then a satellite system may be suggested.
Satellite dishes do not need to be fitted on a roof. They should go on a south-facing wall, where they have clear sight of the sky to the south. If the landlord objects to this, see
Information on new or replacement aerials for rented properties | Switchover Help Scheme .
Any reputable installer should have the necessary training and insurance to fit roof aerials. The help scheme has unfortunately contracted the lowest bidders - Carillion are not themselves TV installers or experts, they're just arranging the contractors. Contact the scheme using any of the methods listed at
Contact us | Switchover Help Scheme .
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Briantist: There is no page for the Budleigh Salterton relay (SY043825). This is a relay of/SFN with Beacon Hill.
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Mike Anderson: The BBC's system doesn't show a problem at Beacon Hill or at Wenvoe (a distant possibility). I can't get it to recognize the new Budleigh Salterton relay, which doesn't seem to appear on this site either. However, Budleigh Salterton operates in a Single Frequency Network with Beacon Hill, so if it had failed you should still get some signal from Beacon Hill, though notably less as Budleigh is vertically-polarized while Beacon Hill is horizontal.
Which direction does your aerial face, and which way is it polarized? That is, do the elements go left-to-right or up-and-down?
Normally I'd say to report the problem using the 'BBC Reception test' link next to your message, or in the top-right corner next to your postcode, but the BBC site thinks your postcode isn't in coverage. You can still try submitting a complaint through that route.
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Sunday 12 June 2011 11:52PM
nats: Can you provide a full postcode? Any idea which transmitter your aerial is pointing to?
Emley Moor does provide an early HD service on C39. It's likely that you were getting fringe reception from here and that the conditions are only right for this to work from time to time.
Worksop looks like it might be within Emley Moor's analogue coverage area but the temporary HD service is on very low power. The preferred transmitter is Belmont, which does not yet broadcast HD. If your aerial points east, you will be getting reduced signal levels as well.
Keep an eye out for information regarding switchover at the Belmont, Waltham and Emley Moor transmitters. Belmont will start HD transmissions on the 17th of August, Waltham on the 31st, and Emley Moor transmissions will go full power, on final channels, on 21 September.