menuMENU    UK Free TV logo Help!

 

 

Click to see updates

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
Removing all barriers to communication between diverse cultures1
How do I get a test card with Freeview2
What can I do when my Sky Digibox says 'No Signal' or 'Technical fau3
Can I receive UK TV in Ghana?4
I would like to know if it is possible to receive UK terrestrial Freeview servic5
[][][
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, 7 August 2012
M
Mazbar
sentiment_satisfiedGold

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

link to this comment
Mazbar's 382 posts GB
Friday, 10 August 2012
S
sandi Kitchin
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.

link to this comment
sandi Kitchin's 1 post GB
M
Mark Fletcher
sentiment_satisfiedGold

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 !

link to this comment
Mark Fletcher's 673 posts GB
M
Mark Fletcher
sentiment_satisfiedGold

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 !

link to this comment
Mark Fletcher's 673 posts GB
J
jb38
sentiment_very_satisfiedPlatinum

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.

link to this comment
jb38's 7,179 posts GB
Sunday, 12 August 2012
G
George
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?!

link to this comment
George's 1 post GB
Dave Lindsay
sentiment_very_satisfiedPlatinum

6:51 PM

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

link to this comment
Dave Lindsay's 5,724 posts GB
Thursday, 23 August 2012
D
dennis
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

link to this comment
dennis's 2 posts GB
Dave Lindsay
sentiment_very_satisfiedPlatinum

10:06 AM

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.

link to this comment
Dave Lindsay's 5,724 posts GB
M
Mark Fletcher
sentiment_satisfiedGold

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.

link to this comment
Mark Fletcher's 673 posts GB
Select more comments

Your comment please
Please post a question, answer or commentUK Free TV is here to help people. If you are rude or disrespectful all of your posts will be deleted and you will be banned.







Privacy policy: UK Free Privacy policy.