How can I improve my Freeview signal?

Will a tv aerial booster improve the signal quality of some freeview channels?

• I have problems receiving the digital ITV (1,2 etc..) and most Channel 4 channels (except E4+1 and FilmFour). My freeview box says that the signal for the ITV/Channel 4 channels is ...show more

• Answer:

  Please read all this. It's got some backgound info that will help you to understand the issues involved. Even as I'm typing this answer there is a man on my roof installing a new aerial. This is because I have had exactly the same issues as you are having. The fact is that Freeview channels are not transmitted in the same way as analogue channels. They are multiplexed, which means that several channels are transmitted on each frequency and your telly or Freeview box sorts them out. Now the complicated bit. The analogue signals are transmitted on a one-channel per frequency basis. Each digital "multiplexed group" is transmitted on a single frequency (so you have several tv channels on one frequency ). The digital transmitter belts out many frequencies, each carrying up to four tv channels in its multiplex . No television aerial is at its maximum efficiency across the whole of the band of frequencies sent from your local transmitter. Even if you have the correct aerial for your region. Therefore, if your aerial is at its weakest at the frequencies used by the ITV/Ch4 multiplex you will always get problems with those stations. If the signal isn't good enough then your equipment will have problems and your Freeview picture will go blocky then fail completely. You are correct in reasoning that the signal quality is as important as raw strength, but bear in mind that the meter on the telly is a bit of a crude device and won't tell you the whole story. An analogue picture will degrade 'elegantly' when the signal deteriorates. That is, it gets grainy and snowy and ghosty but you can still watch it. A digital signal tends to be Go or No Go. This means that (in non-technical terms) the available radio frequency energy at your aerial has to be higher for Freevew than for analogue signals. It also has to be free of interfering signals from nearby electrical sources. These can corrupt a digital transmission. A damaged cable can also cause problems. The bad news is that a simple booster amplifier will not cure your problem. All it will do is to amplify the background noise and distortion. They were fine in the analogue days, but not for digital. You can buy specialised amplifier/filter units that will clean up your signal but these are very expensive compared to a simple booster. You would also have to use a specialist supplier (don't even think about Curry's or Comet for that sort of thing). Also, if it goes wrong you'll have no television again. Consider the relative costs of buying and installing a filter/amplifier with that of getting a new aerial installed (about £100 or so). You spend a lot of money on your television set so getting the best signal source (aerial, digibox, dvd player etc) is reasonable to get the best from your tv. Sorry it's a long answer but I hope that now you're armed with some background info you'll be able to make the right choice. Merry Christmas, and I hope that you will be able to watch the programmes.