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.
All questions
In this section
Saturday, 7 March 2015
M
MikeB11:11 PM
Ben: We need a postcode for a start to diagnose a problem, since we need to know where you are in relation to your transmitter. You also need to confirm that you are tuned into that particular transmitter, and what your signal strength is (same goes for Graham).
One thing you could try - if your losing a mux, it could be a problem with your aerial system (loose connection, etc). Check the lead from the wall socket to your TV, to make sure its working properly and is not loose.
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Sunday, 8 March 2015
J
jb389:32 AM
Graham : In addition to that said in my previous (7:25PM) reply. You should also try swapping the jumper leads over between the TV in question and the other known to be OK, if this makes no difference to the situation, have a look at the aerial input socket on the problem TV and check that its circular centre section, the part that grips the middle pin of the coax plug, hasn't become widened, crimping same (slightly) if necessary.
By the way, that said is on the basis of you having reported that two other TV's are OK, and which its assumed, are being used on the same aerial system.
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J
judith 10:05 AM
why have i lost channels on my freeview channels and other all keep breaking up into tiny mega pixals?
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Thursday, 12 March 2015
G
Gilbert10:09 PM
Would getting an aerial booster help with this problem?
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J
jb3810:59 PM
Gilbert: The question has to be, help with what problem? although should you be referring to any type of erratic reception? then advice can only be given with knowledge of your location, this preferably being in the form of a post code or one from nearby, e.g: a shop / post office, this info being required in order to access details of the transmitter covering the area you happen to reside in.
If though you are referring to channels missing? then carry out a "factory reset" followed by a retune on whatever device you are using.
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Thursday, 19 March 2015
K
Karen McIntyre10:43 PM
Hi we are having problems in not recieving itv2,3,4 and channel 4 stations we recieve bbc stations can you help its costing a fortune had aerial guy in put a new box on the aerial as it had corroded ,blamed our tvs bought new ones have checked all connections it has built in freeview still missing the channels but get them sometimes.is there anything I can buy to help my postcode is ka216az
Kind regards
karen
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Dave Lindsay
11:04 PM
11:04 PM
Karen McIntyre: Look at this as two separate issues:
First and foremost you might find that you cannot receive the COM channels all the time without difficulty. The COM channels carry ITV3, ITV4, Pick, 4Music, Dave, Yesterday etc. This is because the frequencies used are shared by Divis in Northern Ireland. Unsurprisingly, we have had reports on here of issues like this along the coast, including in Saltcoats and I have made postings about this before:
https://ukfree.tv/pred…5901
See here for a full list of Freeview services by multiplex ("Mux"), which are either PSB or COM:
Digital UK Industry - Channel listings
As for the difficulty with reception of PSB2 multiplex (which carries STV, Channel 4, Channel 5, ITV2 and others), this frequency is not shared with Divis, just as PSB1 (BBC TV and radio) is also not.
What you must appreciate is that you do not have line-of-sight with Darvel. From about a mile out the ground drops down to you meaning you are trying to receive what signal is bending around the obstruction:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
The lower you are the more likely you're going to have issues, and I see you're in a bungalow with Adams Avenue and the houses on it being higher up, further compounding the issue.
It's not uncommon in such situations to find that the signal comes and goes, as the weather changes, what's on the terrain changes and so on.
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Friday, 20 March 2015
J
jb3812:25 AM
Karen McIntyre: I am personal acquaint with the vagaries of reception along most of the Ayrshire coastlines, likewise can say, that about the only way of achieving satisfactory "all year round" (or 99.9% anyway) reception in areas such as yours (and beyond) is by changing over to Freesat, as problems of the nature such as presently being experienced will never really vanish for any great length of time.
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K
Karen McIntyre11:47 AM
Hi we are having problems in not recieving itv2,3,4 and channel 4 stations we recieve bbc stations can you help its costing a fortune had aerial guy in put a new box on the aerial as it had corroded ,blamed our tvs bought new ones have checked all connections it has built in freeview still missing the channels but get them sometimes.is there anything I can buy to help my postcode is ka216az
Kind regards
karen
thank you for your help in this matter looks like freesat is the way to go
kind regards
karen
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J
jb389:38 PM
Karen McIntyre: Although in areas such as yours the Freesat route is indeed the best way to go, as reliable reception is virtually guaranteed using this mode, heavy thundery type downpours or snow on the bowl of the dish being about the only things that can affect it, although only for a one or two minutes or so in the case of a downpour. But though purely out of curiosity, on the occasions where your reception has gone downhill, are you aware as to whether or not your neighbours are also experiencing similar difficulties with their reception?
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