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.
Charles: Have a look for Single frequency interference | ukfree.tv - independent free digital TV advice please.
| link to this comment |
1:16 PM
I have lost chanel 4 5 and some of ITV since the changeover started in this area.I keep re tuning and they sometimes come back but then bad reception again.My ariel is fairly new and on a pole.
My postcode NG349HR
| link to this comment |
10:08 AM
I'd like to post a solution to the common problem of loss of multiplex 2 -which carries ITV1, Channels 4 & 5 etc in case it is of use to anybody else.
I found the problem was caused by having the aerial feed going through a Sony HDD recorder before getting to the TV. Once I fed the aerial direct to the TV I got back all the channels. Fortunately this TV has in & out aerial sockets so I am still able to provide an aerial feed to the HDD
| link to this comment |
9:28 PM
Stewart: Yes very true! but its purely dependant on the signal strength received, as some devices can actually give a slight boost to a signal passing through it whereas others have the opposite effect, and if the latter situation applies in an area where a signal isnt that particularly strong, then any reduction in its strength can cause it drop below the receiving threshold of the TV in use.
| link to this comment |
1:32 PM
Hello, I have recently purchased an LG37 with built in freeview, i was so exicted to set it all up, but I was saddened to find out I can only get a handful of freeview chanels, and most of the channels I CAN get, break up, jutter ect ect. What is going on?!
| link to this comment |
2:10 PM
Mike: Its quite impossible for anyone to offer assistance with any question involving reception when a persons location is unknown, this preferably supplied in the form of a post code for maximum accuracy, or at least as accurate as a reception predictor ever can be!
| link to this comment |
1:55 PM
Derby
have lost itv,ch 5,and others since i retuned. aerial on roof.
| link to this comment |
george's: mapG's Freeview map terrainG's terrain plot wavesG's frequency data G's Freeview Detailed Coverage
george: Please can you see Single frequency interference | ukfree.tv - independent free digital TV advice ?
| link to this comment |
9:28 AM
Lowestoft
Channels fine for month...thunderstorm yesterday channels all gone...did rescan and nothing...thanks
| link to this comment |
Scott's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage