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
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Saturday, 27 July 2013
V
Vera9:36 AM
London
How do I get BBC channels and other channels that have been lost after retuning because of no signal. TV is Hitachi and I live in London N22 8JU communal ariel on the roof.
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Vera's: mapV's Freeview map terrainV's terrain plot wavesV's frequency data V's Freeview Detailed Coverage
J
jb3810:23 AM
Vera: You are indicated as being able to receive PSB channels from both Crystal Palace and also Alexandra Palace, although if you normally receive ITV3 etc then you will most likely be using Crystal Palace.
These channels should return automatically by carrying out a second auto-tune, have you tried this? but though when you say "other channels" if you are referring to BBC or ITV channels then you can manually tune in the mux transmitters used by these programmes by entering your TV's set up menu and selecting manual tune / DTV, this then followed by entering and scanning each of these three muxes in turn starting with Ch23 (BBC), storing the results, mux Ch26 (ITV1) being next, then finally the HD service (if used) Ch30.
If by any chance these are not received then use the following three muxes used by Alexandra Palace : Ch49 / Ch58 / Ch54.
Further advice dependant on results, although you should really persevere with the auto-tune procedure as it should not really be necessary to have to resort to manual tuning, however if as it would appear that you "might" be connected to a communal aerial system it would be advisable to check with others to determine if they are also having problems similar to yourself.
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Thursday, 1 August 2013
T
Tanya Wilson8:03 AM
Hi, I have a Goodmans TV in my kitchen which has worked fine until a couple of weeks ago when we had a storm. It now doesn't seem to pick up ITV and C4. BBC channels are fine. I have retuned and still the same! The ariel is fed through the wall from the living room, and the tv in there works fine. I am PE135QS.....Help!
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Friday, 9 August 2013
P
Paul2:06 PM
This seems like an interesting thread, but I have associated but probably different problems.
STV1 & C4 disappeared recently - I'm assuming something to do with the 31st July chanages at Knockmore (our local transmitter).
Retuning makes no difference.
The box shows good quality/signal strength for both channels, but no picture. Some other channels on PSB2, like ITV3 are still ok.
The encoding looks identical to that used for PSB1 (BBC1, etc), which works fine, so I think that I can discount the box (Fortec Star FS-3100, firmware from 2006), though a TV in another room works fine (which would suggest the box).
So does anyone know that details of what changed on the 31st July, and why it might show up these symptoms?
Thanks!
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J
jb388:40 PM
Paul: The only change made at the Knockmore transmitter was that its COM6 Ch60 frequency was slightly lowered so as to operate with a negative offset, i.e: 786.0Mhz down to 785.8Mhz.
By the way ITV3 is on the COM4/SDN multiplex whereas STV is on PSB2 Ch23, have you tried to "manually" tune in this channel? but though with these type of problems its usually always best to remove the aerial and carry out an auto-tune to blank out anything stored, then carry out a second auto-tune AFTER having reconnected the aerial.
If this makes no difference then the box should be completely reset.
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Saturday, 10 August 2013
P
Paul1:08 PM
Fochabers
Sorry meant ITV2 (not ITV3) missing. It is all on C23/PSB2.
For C23 channels, the box showed Signal Intensity at 81% and Quality at 97%. But no picture.
Tried a manual retune on just C23, but to no effect.
Restored Factory Defaults, and rescanned. Lo and behold it is back! Odd, but there you are.
Thanks, jb38. Much appreciated.
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Paul's: mapP's Freeview map terrainP's terrain plot wavesP's frequency data P's Freeview Detailed Coverage
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jb383:54 PM
Paul: Pleased to see that that the factory default procedure cured the problem, as starting afresh is about the only way of clearing a digital receivers memory system of any form of corrupted data that may have been picked up during the carrying out of a previous procedure.
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Wednesday, 11 September 2013
N
Nathan Lacey3:52 PM
London
Hi,
Just moved into a flat in SW2 5 and set up tv's in my bedroom and living room, both TV's (same model) are plugged into aerial wall sockets. The tv in my living room works perfectly picking up all channels, however, the tv in my bedroom doesn't pick up any ITV, BBC or Channel 4 channels but does pick up Dave, Bid Up TV, QVC etc. Why aren't the old 'terrestrial' channels working, presumably the wall sockets are linked to the same aerial? Any advice would be hugely appreciated.
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Nathan's: mapN's Freeview map terrainN's terrain plot wavesN's frequency data N's Freeview Detailed Coverage
J
jb384:43 PM
Nathan Lacey: As both TV's are the same model (if referring to model number?) then as the living room TV has a full compliment of channels you should try swapping the two sets over and check if the living room TV can still receive all the channels when using the bedrooms aerial socket.
If though it does, then carry out an auto-tune on the ex bedroom TV thats now connected into the living rooms aerial feed and check the results.
By the way the quick way to check reception from all six muxes is to run through the EPG list as follows.
1 - 3 -10 -11 - 18 - any HD channel.
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N
Nathan Lacey7:51 PM
Thanks for your reply JB.
I swapped the TV over and no success, the living room tv said 'No Signal' on channels 1-10. I have also tried restoring the tv to factory settings but no luck.
Might be a silly question; but how do I run through the EPG list?
Thanks
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