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My ITV/C4 Freeview channels have disappeared - what can I do? Is it my SCART ca

My ITV/C4 Freeview channels have disappeared - what can I do? Is it my SCART cable?

My ITV/C4 Freeview channels have disappeared - what can I do?
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
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Can I receive UK TV in Ghana?5
In this section
My Freeview box has no EPG, is blank on FIVE, ITV3, ITV4, ITV2+1, has no sound o1
I have now lost all signal can you tell me what the problem might be?2
I have a Durabrand cg5660-m and I need the lock key code!3
What is the Inversion Effect and why does it effect my Freeview TV reception? 4
My high gain aerial can't get all the Freeview channels I expected5
What are the aerial types about? Are they high-gain?6

Comments
Monday, 11 July 2011
B
barry
7:52 PM

i have two tele's with built in freeview which are connected to a roof aerial, everything has work fine till tonight got home and no itv1, chennal 4, 5 ect. can you help with this please.

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barry's 1 post GB flag
J
jb38
sentiment_very_satisfiedPlatinum

9:30 PM

barry: It would be of great assistance to anyone possibly giving a reply if you indicated your location, as that would enable the status of the transmitter most applicable to your area to be checked.

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jb38's 7,179 posts GB flag
J
jb38
sentiment_very_satisfiedPlatinum

9:50 PM

Kerrie: Assuming that what you are meaning is that the Freeview+ box doesn't pick up as many channels as your Freeview TV, then this is not necessarily an unusual thing to happen, as it all depends on the sensitivity of each of the devices being used, no two ever being the same.

I should say that you are forecast as being possible to receive TV from two sources, Sutton Coldfield and Waltham, although Waltham by far having the edge on the other.

Another thing that can also apply is the aerial arrangement used to feed the devices, as looping in-out will reduce the signal to the last item in the chain, so the use of a two way powered splitter is always the best way to split a signal, as each set then gets the same signal.

This only being mentioned in case it applied, but you should give the Freeview + box another scan as it will only store what was receivable at that particular time, any glitches that may have occurred at the time stored as such, Freeview not updating the situation.

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jb38's 7,179 posts GB flag
Wednesday, 13 July 2011
C
Colin Gleadall
2:30 PM
Birmingham

2 or 3 weeks ago we lost some of the main channels from all our TVs/PVRs - as if some changes were being implemented at the transmitter. Most returned but now we cannot receive ITV4 and possibly other related channels. We have not changed the aerial, connections etc. We have had no problems with this aerial or set-up for the past 2 years until now. I have tried clearing and re-tuning, to no avail. I thought that the signals were due to get stronger, not weaker!

Birmingham B28 0LT via Sutton Coldfield. We are in a slight dip. Some neighbours have more modern aerials, but why would ours suddenly become inadequate?
I am missing the Tour de France!!!

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Colin Gleadall's 2 posts GB flag
Colin's: mapC's Freeview map terrainC's terrain plot wavesC's frequency data C's Freeview Detailed Coverage
Sunday, 17 July 2011
Tuesday, 19 July 2011
J
june
9:24 PM

have aerial on roof had all my freeview channels up until 3 days ago missing my film 4 magic radio and others keep scanning and unplugging plz help thanks

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june's 1 post GB flag
Sunday, 24 July 2011
C
Colin Gleadall
11:29 PM
Birmingham

Further to my post of 13th July, I have found corrosion of the aerial connection into the splitter/booster. I replaced the connector and splitter. I can now receive all channels. Presumably the weaker channels were insufficientl to overcome the bad connection. I also chevked the aerial in/out of PVR etc.

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Colin Gleadall's 2 posts GB flag
Colin's: mapC's Freeview map terrainC's terrain plot wavesC's frequency data C's Freeview Detailed Coverage
Monday, 25 July 2011
Briantist
sentiment_very_satisfiedOwner

8:58 AM

Colin Gleadall: I am really pleased to hear you located and fixed the problem. You are correct, the channels with the weaker signal are most effected by the problem you found.

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Briantist's 38,915 posts GB flag
Saturday, 6 August 2011
C
Charles
9:04 PM

Here's an odd one. I have an old TV and freeview box that work perfectly in my kitchen. I get all channels and no interference. I also have a Samsung flat panel with a built in Freeview receiver. Both are run off the same aerial running through a signal booster.

The Samsung often gets interference on all BBC Channels and never picks up Film 4. I have re-tuned 'til I'm blue in the face. Why?

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Charles's 1 post GB flag
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