My ITV/C4 Freeview channels have disappeared - what can I do? Is it my SCART ca
Brian Butterworth published on UK Free TV It is a feature of television signals that they can be effected by the weather. Aside from the obvious damaged that can be caused by wind or torrential rain, the onset of summer can cause a more intriguing problem called "inversion".
Basically, when the sun heats up the land, the hot air can get trapped below cold air at high level. This creates an "inversion layer" which acts like a polished mirror to TV signals. This causes two problems: you can receive both the original and a reflected signal from your own transmitter (on analogue TV this appears as "ghosting") or interference from TV transmitters that are normally too far distant.
The ITV/C4 multiplex of channels (ITV-1, ITV-2, ITV-3, ITV-4, CITV, C4, More4, E4, Quizcall) use a transmission "mode" called 64QAM, and it is sadly much more prone to these problems.
So, whilst a loft-mounted aerial will provide reception at some time, it will fail at others. The only real solution is to mount the aerial (or a new Class I aerial) outside on a pole, but some people report that changing the cable from the aerial to the set-top box to the high-grade satellite cable can also help.
The SCART connection, by the way, only carries a single TV picture, not the Freeview transmission multiplexes, so if this is disconnected it will result in degradation to every channel at once.
8:01 PM
Why is the ITV (& CBS) signals so poor on my FreeSat... other broadcasters like the BBC are just fine? I tried watching ITV4 European football games... it was hopeless quality, when the plays moved it was just a blur and the grass looks just luck a smudge. I had to switch it off in the end. Surely there is a minimum quality that broadcasters must adhere too?
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12:11 PM
My digital itv and channel 4 channels are intermittent. They work some of the time but the majority of the time show no signal. I live in the SA14 area. Can you give me some guidance. Thanks
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12:53 PM
Julian: The most likely and therefore first thing to check would be that it is tuned to the correct transmitter, which is the one to which the aerial faces. The tuned UHF channel and/or frequency in MHz is usually given on the signal strength screen. Check that this matches that of your desired transmitter.
More guidance can be given with knowledge of that transmitter, or at least a postcode and direction of aerial which should allow the transmitter to be determined.
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1:21 PM
What I don't understand is why an aerial - which has performed perfectly well for years- has suddenly stopped picking up ITV, C4 and C5?
We have had bad weather recently but we have had worse without any problems.
I have been on the roof, checked all the cables and the aerial itself is rock solid, it hasn't been moved in years, the connections are all good too.
I also note a lot of other people posting this month about these channels?
Buying a new antenna doesn't explain why these channels have disappeared overnight.
Thanks for any guidance you can give.
Ian
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6:38 PM
Ian: Essentially, your signal comes to via a thin bit of copper, part of which sits outside all year, in all weathers. Although you've checked everything, its almost certain that there is a fault somewhere along that path, perhaps a crack in a join which allows moisture to get in, or a connection starting to go.
If you read through all the complaints about poor signal, etc, those that come back with the problem corrected (which most people dont, unfortunately), its normally a problem with the cable.
You havn't given us a postcode, so we cant check your signal path, etc, but you could try plugging in your TV to a neighbours aerial, and perhaps borrowing a TV from them, just to check if its any other equipment. The other thing to do is to change the aerial lead. This simple fix has worked several times - if its a bit duff, then a swapout might cure the problem.
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7:56 PM
Dear Sir,
I have three televisions in our house, all with loft aerials which work fine, two receive Freeview Dave on channel 12, but the Samsung LED tv decided not to show channel 12 only 10-13 recently,I have default factory setting fully re-tuned to our part of the country, but still no Dave on 12.
Any more ideas please ?
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8:42 PM
Mr Mark Sandeman: Dave is transmitted on ArqA / COM5, the same multiplex as used by (11) Pick TV / (132) Sky news / (41) Food network etc, should you not be able to view these channels either then you should carry out a manual tune on COM5, the problem being that I am unable to provide the Mux channel number to scan as you haven't given your location, this preferably being in the form of a post code or one from nearby, e.g: a shop / Post Office.
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9:05 AM
Bury
Thanks for replying Mike. That explains it. I shall get an engineer to check and replace the cable and/or junction box because I hate going on the roof.
Postcode is BL9 6NN. I think the signal is ok? We have ruled out the equipment issue because it is the same on two different TVs in the house. Yet we get ITV on HD though presumably that's on a different mulitplex?
The only thing left then is, as you say, the cable or possibly the junction box on the wall into which the two cables from the house meet. I had to push one of the connectors back into this box because it was a bit loose - I thought that would resolve the problem but probably water has got inside that, as you suggest.
I shall come back when the problem is solved!
Thanks again,
Ian
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
10:17 AM
Penzance
Dear JB38
My post code is TR20 8AZ
I hope this helps
Have tried manual tune on Channel 25 for Dave but it did not want to store it
Thank you very much
Mark Sandeman
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Mr's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
10:26 AM
Mr Mark Sandeman: Redruth is indicated as being the station that covers your area, and with COM5 / ArqA transmitting on Mux C52.
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