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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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Removing all barriers to communication between diverse cultures2
How do I get a test card with Freeview3
What can I do when my Sky Digibox says 'No Signal' or 'Technical fau4
Can I receive UK TV in Ghana?5
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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
Tuesday, 19 September 2017
S
StevensOnln1
sentiment_very_satisfiedPlatinum

11:04 PM

Janey: Retuning was a bad idea as it will never fix a problem like this as the TV was already correctly tuned. Have you checked for any loose or damaged cables or connections? If the problem started during bad weather it's possible that water has gotten in to your aerial system.

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StevensOnln1's 3,299 posts GB
Monday, 25 June 2018
M
Mike
4:47 PM

I live in Wrexham with aerial pointed on Moel Y Parc. Aerial has masthead amplifier then feeding into a 6 way Proception distribution amplifier with 3 tv's connected and a fourth connection to a Humax Fox T2 set top box.
Full output on amplifier is terminated correctly.
The Humax box plus the Philips tv receive all channels correctly.
The other 2 TV's - a TEAC (dixons) and Luxor (asda) receive all channels except Channel 4 and local Made In Wales on ch8, plus I suspect a few others.
The Humax and Philips show signal strength around 40 -50% with quality 100%, other sets have no indicator.
Means we can't watch Channel 4 in bedroom or kitchen !

Previously we used signal from Wrekin (West Midlands) but want Welsh services now, so aerial realigned and all sets retuned.. All Tv's worked correctly delivering all channels from the Wrekin .

Any ideas ? Have swapped outputs on 6way amp to no avail

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Mike's 2 posts GB
S
StevensOnln1
sentiment_very_satisfiedPlatinum

7:26 PM

Mike: Please provide a full postcode so that we can see the predicted signal strength at your location. Does your amplifier have a variable gain control? If so, try adjusting it up and down and see if that makes any difference.

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StevensOnln1's 3,299 posts GB
M
Mike
9:05 PM
Wrexham

Mike: Post Code LL12 7SH Amplifier does have gain control.
Just checked which channels not received in kitchen - there are 22 spread across more than 1 MUX - Ch nos 7,8,40,45,50,55,56,57,67,68,69,72,74,82,84,86,87,93,94,95,96,97. May be more in higher number channels.
Adjusting amplifier gain not easy - at top of 12ft pole !

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Mike's 2 posts GB
Tuesday, 26 June 2018
MikeP
sentiment_very_satisfiedPlatinum

3:52 PM

Mike

From the signal strength you report it looks like you need to access the amplifier and turn up the gain. 40% is too low for some TVs with less sensitive tuners. Ideally you want between 60% and 85% strength on all multiplexes.

As StevensOnln1 says, a full post code will help us by showing the expected reception at your location.





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MikeP's 3,056 posts GB
Friday, 20 July 2018
C
christine
6:40 AM

Janey: hi live by the coast near Great Yarmouth and have had freeview aerial man out aye signal is strong but my TV with a Bt box keeps losing Itv3 etc surround sound and HD channels it keeps saying poor signal and so I retune then I loose more channels ! Normally have 152 but down to 109 ! Then next time I tune within A few minutes finds the odd channel have got a new BT box and it still does the same this has only happened since we changed in July and retuned Tv driving me mad

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christine's 3 posts GB
Friday, 12 October 2018
M
Michelle Chamberlain
10:24 AM

Hello can you help my parents have a tv with built in freeview,they can get all bbc channels but it v ones are all distorted and keep breaking up any ideas how to resolve this?
Thank you Michelle

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Michelle Chamberlain's 1 post US
MikeP
sentiment_very_satisfiedPlatinum

10:32 AM

Michelle Chamberlain:

Please provide a full post code for their location so that we can examine the predicted reception conditions there. That is only possible with a full post code being provided as requested in the text above the entry box. There are over 1100 transmitters and with the full post code we will then be able to see which are receivable at their location.



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MikeP's 3,056 posts GB
Tuesday, 15 January 2019
S
Stel
12:16 PM
Sunderland

Since last week When watching tv through Humax pvr , my ITV,CH4,5,ITV2 etc channels indicate weak or no signal, with snatches of picture and distorted sound or nothing. My postcode is SR2 7JR

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Stel's 1 post GB
S
Steve
1:10 PM

What is happening to digital TV - these problems never occurred with analogue, if and when they did we were notified with some sort of test card.

It would appear that when digital goes down, hard cheese and we are left to wonder whether our equipment is failing or is it transmitter trouble?

I have a humax pvr and a panasonic DVD recorder both fitted with freeview.

At present the BBC channels, ITV channel 4 and 5 and other channels on that bandwidth are working.
I was hoping to watch the Bill on the drama channel (20), but this channel has the "no signal or scrambled message" showing.

I have recently had a new log aerial, co-ax cable, and connections fitted, all were giving 54% for strength and bouncing up and down between 40% - 90%, with picture freezing and or pixcellating.

When it rains constantly this seems to be the norm.

Totally dreadful and no one can be contacted to query if there is anything wrong.

The last time it happened my wife checked on line and it stated there were no issues, so where was our channels?

About half an hour later they were back.

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Steve's 1 post GB
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