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.
6:21 AM
Steven: Where in liverpool do you live ? A postcode will help i cover most of liverpool so i might be able to help
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10:09 PM
Sudbury
4 days ago I lost "Dave". No problems before. I have re-scanned channels twice but "dave has completely disappeared. Arial on roof all connections checked. Arial for second TV new but lost "Dave" also. Is this atmospherics?
I have now re-scanned twice.
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sandi's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
11:11 PM
Halifax
Sandi Kitchin.Yes as an anti-cyclone (or high pressure) is over much of the UK as present atmospherics is the likely culprit.
Look up inversion effect for full details !
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
11:18 PM
Halifax
Mazbar.If this helps,Steven in Liverpool as the postcode L15 4LF which is Picton Road,Wavertree area of the city.
Steven,i would look up inversion effect as a likely culprit due to high pressure !
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
11:39 PM
sandi Kitchin: Once you recovered Dave you should resist the temptation to carry out re-scans if you find that a channel that was previously OK now gives a blank screen, because the channel will NOT have been lost from your TV or boxes memory but almost certainly WILL be if a rescan is carried out, as the only reason the screen is blank is because the signal has dropped slightly and is sitting under the level that's strong enough to produce a picture, but will do without altering anything when the level rises again.
You can prove this by carrying out a signal strength check whilst on the blank screen, then doing likewise when the picture returns, as when the screen was blank it will have been indicating a lower level.
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6:21 PM
My mother is in NR17 and is having problems with ITV and Channel 4. The picture is pixilated despite having retuned all the channels. The strange thing is the channels are working fine on her other freeview TV, which is connected to the same aerial.
Any ideas?!
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George: First off, check that it is tuned to UHF channel 59 for ITV1 by bringing up the signal strength screen. This is to ensure that it is the signal from Tacolneston that is being received.
If it is tuned to Tacolneston, then perhaps it is too much signal due to your mother's close proximity to the high-power transmitter:
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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12:22 AM
Hi,just lost dave,film 4 and e+1,tried re-scan and now channels appear to not exist, any help please,postcode is pr8
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dennis: I guess that you're receiving your TV from Winter Hill (or not as the case may be).
Refer to the page for the transmitter (by clicking its name above):
-> "Transmitter works 23 August 2012: Engineering transmitter work will take place between 00:01hrs and 06:00hrs. TV services that will be disrupted: Analogue services - n/a Digital services - PSB1, PSB2, PSB3, COM4, COM5 and COM6 will be subject to periods of shutdown."
-> "Over the next week Winter Hill main transmitter: TV (digital) Liable to interruption, Radio (analogue) working normally, Radio (digital) working normally."
It looks like engineering work is going on overnight. In situations such as this, don't retune your receiver because all it does is loose the tuning information which is correct anyway.
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12:53 PM
Barnsley
Dennis.A full postcode is preferable not a partial one is required to ascertain reception likelyhoods in your locality.
PR8 is Southport in either Merseyside or Lancashire,and Southport can receive either Winter Hill or Moel-Y-Parc main transmissions.
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage