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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Thursday, 25 April 2013
K
KMJ,Derby12:08 AM
typo, should read "frequency of the multiplex" in the post above.
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C
Catherine12:59 PM
Hi JB38
Thanks for your reply. I don't know if they've got a problem with the same channel number, only that most of them lost the bbc channels. I will try to find out. My TV doesn't give the option to reset or do a first time installation, only auto or manual retune. But I did wipe all the channels by retuning with the aerial out and then again tuning with it in.
And to KMJ, thanks for the comments, I'm not quite sure how to do a manual tune for ITV2+1 other than going to channel 27. and with film 4 it wouldn't let me choose channel 16 (the lowest channel available in the manual tune was about 20). Thanks again.
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J
jb386:24 PM
Catherine: These numbers you are referring to are the EPG (electronic programme guide) numbers that simply informs you of all the programmes that you can view from Mendips six transmitters, and when you select one of these programmes your TV / box switches on the appropriate mux transmitter channel.
The numbers I am referring to are the actual multiplex "transmitter" channel numbers that carry all of these programmes, and with ITV2+1 along with a host of other programmes being carried on what's known as the COM4 / SDN multiplex on Ch48, and so its Ch48 that you should be manually tuning.
Film 4 is transmitted on the ArqB multiplex (also known as COM6) on Ch52, and just like mux Ch48 also carrying host of other programmes, and so in this case you should manually tune mux Ch52.
This was the reason for me emphasising to make sure that your neighbours were referring to exactly the same programme EPG number as you, just in case they were referring to ITV2 which is on a different multiplex from ITV2+1, the former being on PSB2 (D3&4) mux Ch54.
(Ch48 an) (Ch48 an) (Ch48 an)
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J
jb387:31 PM
Catherine: Please ignore the two Ch48's in brackets seen at the bottom of my reply, haven't a clue where they came from!
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Monday, 29 April 2013
G
Ganesh9:36 AM
Romford
Hello,
I am not recieving the following channels :
Channel 4, Channel 5, ITV 1 and ITV 2.
I stay in Romford . Recently moved into this apartments.
I have connected to Freeview directly to my digital TV.
Could you help me?
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Ganesh's: mapG's Freeview map terrainG's terrain plot wavesG's frequency data G's Freeview Detailed Coverage
Tuesday, 30 April 2013
C
Catherine11:53 AM
Hi JB
Thanks so much for your explanation. I manually tuned on channel 48 and my signal for ITV2 has gone up for 30% to 55% so it's now watchable most of the time. It didn't work with Film 4 though.
There are 8 other neighbours who share this aeriel. I know two at least use Virgin for their tv but checked with one who just has freeview (ahd is also on the ground floor) and they have a perfect signal/recepetion for both ITV2 and Film 4.
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J
jb384:00 PM
Catherine: The fact of your neighbour being able to receive Film 4 whereas you don't could simply be due to the fact that your neighbour is receiving a slightly stronger signal than you do on Ch52, yours possibly being under the level required to produce a picture whereas theirs is above, and so I would like you carry out a signal level check by proceeding as though you were going to carry out another manual tune on mux Ch52 but though (important!) this action NOT being followed by pressing search or scan after having entered 52 into the box, because by NOT pressing search or scan if any signal is being received the levels (strength & quality) should immediately be indicated on the bars, maybe you could try that and report back on your findings.
But before carrying out the above select ITV2+1 (same mux as ITV3) and carry out a signal level check whilst viewing that programme and which you reported as being 30% to 55%, but no matter what it indicates I would like you to check that the aerial connectors at each end of the jumper cable between the TV and the wall socket are fully inserted whilst observing the indications on the screen for any possible jumping in strength when you move the cable, this test only being requested to ensure that your Film 4 problem is not being caused by a faulty aerial lead.
By the way, its also being assumed that when you mentioned ITV2 that you were really meaning ITV2+1? ITV2 being on the same transmitter as ITV1 whereas NOT where ITV2+1 is concerned, only the latter being on mux Ch48.
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Thursday, 2 May 2013
D
DO DO 7:27 PM
MOST OF MINE GONE ....5, 4 ,3 , AND THE REST EXCEPT BBC, this started weds 1st may.
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J
jb387:50 PM
DO DO : No one can possibly offer any advice without a location having been given, this in the form of a post code or one from nearby such as a shop / post office, it would also be of assistance to know where your aerial is installed, e.g: roof, loft, communal or within the same room.
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Saturday, 4 May 2013
D
Dennis11:00 AM
Woodbridge
Can you help?
My post code is IP12 4JB,I have a roof aerial, and I have a recurring problem with Ch58.I have tried the"disconnect aerial, re-tune, reconnect aerial etc." but to no avail.All other channels are fine but on CH58(ITV3,ITV2+1, Dave,Quest, 5*,5USA etc)the picture is pixilated and the sound is distorted.I had the same problem in January this year which self corrected after a number of weeks.Is there anything I can try?
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Dennis's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
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