Why is Digital Reception a problem? The only reason why digital reception should be a problem is because of the past. We have had analogue television for many years, and most people can get a reasonable standard of reception. However, the frequency bands allocated to television have already been "filled up" with the old four channel broadcasts of BBC 1, BBC 2, ITV and Channel 4. When channel 5 arrived, there was no more room, and so many transmitters had to use bands previously reserved for equipment like Video Recorders, and later DVD players. In order to have any more channels the only answer was to change to digital broadcasting. Digital television needs less transmitter power, and less frequency bandwidth, than does the old analogue TV. Just one of the old channel numbers can now contain half a dozen or more digital programmes.  To reflect this idea, the UHF channels used for digital broadcasting are now known as multiplexes, or mux, for short. It was thought possible to cram in six new multiplexes, despite the overcrowding of the airwaves. Each digital transmitter thus usually handles six multiplexes, called 1, 2, A, B, C, and D. For example, at Tacolneston, Mux 1 is on channel 63, Mux 2 is on UHF Channel 60, A is 53, B is 58, C is 61, and D is 64. There is more about these transmitters elsewhere, but for now, ignore out of date, or mistyped tables which say that Mux C and D are transmitted from Tacolneston on UHF channels either 34, 43, or 46. This information is out of date.

Can I get Digital Television? According to the Freeview website, people in the St Edmundsbury area cannot receive Freeview Digital Television. However, quite a few people in the area have bought set top boxes or digital televisions, and can receive some sort of a signal. So we have to accept that for TV reception, Bury St Edmunds, Haverhill and district are in marginal areas for TV, and it is often a matter of "luck", as to whether you get a good signal. So, just how does this "luck" work? Firstly, not all TV transmitters send out a digital signal. In our area your aerial needs to be already getting good reception from Tacolneston or Sudbury. If you are on a local repeater station such as the Bury or Westley ones, these do not handle digital signals, so your luck is out. Secondly, your transmitter needs to send out a digital signal which your aerial can handle. At Sudbury, for example, the old analogue signals need a Group B aerial, but the digital signals need Group E. So you probably need to get a wideband aerial which covers both groups. If you are changing aerials make sure to get a high gain one, as digital signals are always transmitted at about a hundredth or less of the power of the analogue channels. A potentially weak signal is therefore the third likely problem.  Fourthly, the owners of the airwaves did not know much about digital television either, and they have tried to cram too many programmes into each multiplex, by compressing the digital data, and so some channels suffer from poor quality sound or vision, however good your receiving apparatus is. So you may get some programmes well, and others either not at all, or too broken up to watch. Fifthly, you have already heard that the airwaves are now grossly overcrowded. In some cases the transmission of two adjacent channels can result in what is called co-channel interference. Back in analogue days, this was dealt with by never having any one transmitter using adjacent channels. So at Tacolneston they used channels 52, 55, 59, 62, and 65. The new digital multiplexes were added in as UHF channels 53, 58, 60, 61, 63, and 64. It was hoped that by using a much lower power output for the new channels that co-channel interference will be minimised. However, our existing aerial and downlead set ups at home may now suffer from this type of interference, in some instances.

Is there anything I can do to improve the situation? Yes, there is, but it will probably cost you more money than just the new set top box. You may need a new high gain aerial, and if you already use a masthead amplifier, it may need replacing with a modern screened low noise variety. Ideally, your downlead could be replaced with the new double screened cable, introduced for use with satellite boxes, but giving reduced losses in all circumstances. You may even decide to replace your old ITV digital box with a newer type of improved technology, which can deal with weaker signals better. If you are lucky, none of this may be necessary, but in some cases it may be the only way to get results as good as you were led to expect.

What is Freeview? Freeview is actually a consortium of broadcasters who set themselves up to take over the digital terrestrial channels of ITV Digital following that company's collapse in 2002. The new digital channels are referred to as Freeview as a whole, even though technically, there are still two operators surviving from pre-Freeview days, who are not in the consortium. Freeview is made up of the BBC, Sky, and a Nevada based company called Crown Castle. The BBC operates Mux 1 and Mux B, while Crown Castle operates Mux C and Mux D. The other companies not part of Freeview, are Digital 3 and 4, who operate Multiplex 2, and SDN, who operate Multiplex A.

Has Freeview made any improvements? Freeview has improved the quality of the Digital Experience by reducing the number of programmes in each multiplex. By using a system known as 16-QAM, they have improved reception quality at the cost of 25% fewer channels per mux. This system also allows a better coverage of the country, as the transmissions can extend further. It is also supposed to be more resistant to impulse interference from thermostats, fridges, and car ignitions.  DN and Digital 3 and 4 use the system called 64-QAM, which allows more channels at a lesser quality. These are the channels transmitted on Multiplex 2 and Multiplex A.

What is IDTV? IDTV stands for Integrated Digital Television. An IDTV is a TV which can receive the new Freeview digital channels as well as the older analogue ones. If you have got an IDTV, then you do not need a separate digital adaptor, or set top box, to get digital television. However, your brand new IDTV is still subject to the issues discussed above. You may or may not actually be able to receive Freeview.

OK, So What is DTT, STB, and DVB? DTT stands for Digital Terrestrial Television. It is what you get from Freeview. It is called Terrestrial because it comes from existing land based TV transmitters as opposed to coming from a satellite. You do not need a satellite dish, and in theory you can use your existing TV aerial. An STB is a Set Top Box, but you can just as easily put it by the side of the TV or under it. It is the cheapest way of getting a digital signal and is also called a Digital Adaptor, or a Digital Tuner. If you have an IDTV, you do not need an STB. DVB stands for Digital Video Broadcasting, and means the same in effect as DTT. Any TV with this logo is going to be able to receive Digital TV, it is an IDTV.

Is going digital worth the bother? This may be the only way you can get to watch Channel 5. People in Bury St Edmunds who use the Tacolneston transmitter cannot get a good analogue picture from Channel 5 as it is transmitted at a mere 4kw, compared to the 150kw of the other analogue programmes. People on the Sudbury transmitter should be better in this regard as they get Channel 5 at 50kw by comparison. Several of the other programmes are also worth watching, but keep your Granny away from the shopping channels. If you have toddlers or small grandchildren, you may want to get CBeebies, which they love. It transmits before 12 noon only at the moment. This is only available on Freeview, as is the channel for younger teenagers called CBBC. This can be excellent for older children on a wet day, and broadcasts all day. Many of the better channels do not start to broadcast until 7.00pm, so if you are looking for daytime viewing, this is not frequent on Freeview at present. One plus point for digital is that it is routinely broadcast in widescreen. If you have a widescreen TV and get frustrated by the distortions of analogue broadcasts, you may prefer to go digital. At the moment however, I would not necessarily recommend a change to digital unless you are getting poor results with analogue TV, and you are willing to take some trouble to get it working properly. My own analogue channels 1 to 4 produce a better and more watchable picture than digital, which I sometimes find flat and hard on the eyes. Sound on digital can also sometimes be troubled by loud clicks and harsh cracks. But, if your luck is in, and you can get good digital reception, then the extra choice is well worth the trouble. And all the new developments will be digital, so this is where the future of broadcasting is going.