W
hether you like it
or not, digital TV is marching on, and if you want to carry on watching television in your caravan, you'll need to upgrade in the next few years. The analogue signals which have delivered television for more than 50 years are gradually being switched off. The first analogue transmitters get switched off later this year, but the process will be in full swing from 2008 to 2012.
Preparing your caravan for the digital TV age requires either
a satellite system or a digital terrestrial set-up, using
a conventional aerial. The latter
is certainly the less expensive option, which may well make
this the more popular route for going digital.
What is digital telly?
Digital terrestrial television is commonly referred to as Freeview, but technically this only refers to the package of channels available, rather than the technology.
As the name suggests, Freeview has no subscription costs associated with it, and once you buy the equipment, there are no maintenance costs or contracts to worry about it. It's very hassle free. Digital television delivers lots of improvements over the standard analogue service it is gradually replacing.
The main advantage is the choice of channels on offer. The Freeview service provides more than 40 TV channels; compare
that with the five you usually get
with analogue broadcasting. Granted, the shopping channels and the like are pretty rotten, but you do get the full set of BBC, ITV, C4 and Five's channels, Sky Sports, Sky News and some dedicated children's channels, all of which are pretty good. The improved sound and picture you can expect, and the interactive information services are further advantages of upgrading. Add in the 20 or so radio stations you'll receive in digital quality as well, and the reasons for upgrading become pretty compelling.
TV tech
Put simply, digital terrestrial signals are broadcast from transmitters and received via a rooftop aerial in the same way as analogue. You can use virtually any TV to watch Freeview but, because the signals are digital, you'll need a special receiver or digibox to convert them before they get to the TV. Another difference is that digital signals are very directional. The aerial needs to be precisely lined up to face the transmitter if a good result is to be achieved. Analogue reception is far less sensitive to aerial orientation.
The channels are broadcast in groups known as multiplexes, so in areas with marginal signal strength, you may only get some multiplexes, and consequentially some channels, but not all. If you receive one channel in a multiplex, you will get all of them.
Depending on the transmitter to which you've tuned, you'll find some multiplexes are broadcast at different strengths, so you may only receive certain groups. As
a very rough guide, BBC TV channels are on one multiplex, ITV channels are on another and the other four are split between digital radio, shopping and less mainstream broadcasts.
Equipment check
In order to get Freeview, it's essential that you have an appropriate aerial, a good receiver and that you're within range of
a transmitter. With analogue TV signals, even in ropey signal areas, you can get a grainy picture, but digital services are different. If the signal is good, you get a perfect picture and sound, but anything less than that and you get nothing at all. That's what makes getting the correct equipment essential.
By their very nature, campsites are deliberately located well away from centres of population and as a result, TV reception is often very poor. If you want to get a digital TV signal, a good aerial is a must. Omni-directional aerials are, quite simply, not good enough. Although they can technically receive the digital signal, this will only be usable in the very best signal areas. As we've mentioned, an aerial must be pointed precisely towards the transmitter. Omni-directional units, however, are designed to receive broadcasts from whatever direction they're coming. They cannot be oriented.
Directional roof-mounted TV aerials are better because you
can point them to fine-tune reception, but results can still be very variable. They aren't really large enough and can't get up high enough to make the most of the incoming signal. For optimum results, a free-standing aerial is best; this gives you a lot more flexibility in terms of the height and design of aerial you can go
for. To give yourself the best chance of getting great reception, you want an aerial that looks similar to what you'd find on the roof of house.
An external aerial and mounting pole, such as the Image Complete from Grade UK, will cost around £50. Another possibility is to match up the Smarty aerial and mounting pole from Roadpro. These may be less attractive than the Image Complete, but they can be adjusted higher, which makes them more effective. And they still cost about the same as the Image.
The other piece of equipment that you need is a decoder. You can find one for as little as around £20 at supermarkets and electrical retailers. If you are not always on a mains hook-up, you'll need either
a 12V decoder, such as the Sagem ITD64 12V, or a small inverter to power your regular
unit from a 12V power source.
Be prepared
Nothing can guarantee perfect reception of all Freeview channels everywhere in the UK, due to the landscape and limitations of the technology. There are a few steps you can take to get the best signal possible. Do some research before you set off to find out what Freeview coverage is like where you'll be touring – and whether it's worth trying. Get hold of
a copy of the Television Viewers Guide. This annual booklet, which costs £6, tells you the location of all digital transmitters nationwide, so you can point your aerial in the right direction straight off, rather than guessing. It's available from some TV shops, by calling 01752 872 888 or online at www.radiolisteners
guide.co.uk.
Freeview has its own website (www.freeview.co.uk), but a much more reliable indicator of signal availability is the independent UK Free TV (www.ukfree.tv).
Another must-visit site, aimed specifically at people using slower internet connections, is the
no-frills Wolfsbane reception predictor (www.wolfbane.com/cgi-bin/tvd.exe). This provides details about which channels you can receive, depending on the aerial you are using and how you set the aerial up. Simply type in the postcode or Ordnance Survey grid reference of the caravan site where you'll be pitching up and take the results page with you.
It's also worth contacting Roadpro (tel 01327 312 233, www.road pro.co.uk), the expert on digital TV reception – whether Freeview or satellite – on tour. It stocks TVs with built-in receivers, 12V digiboxes and aerials. Most of all, however, the technical team will help customers get things up and running. Don't expect the same service if you buy your set-up from a supermarket.
Getting started
Armed with the information on the best local transmitters, you need to connect the television, digibox and aerial to each other. The box will need to scan the signal from the aerial to find the available channels before it is ready to use. If the scan is going to find anything, the aerial needs to be pointed in the right direction.
Some of the transmitters require that your aerial be placed on its side or be vertically mounted.
The websites and the Television Viewers Guide tell you which orientation each transmitter uses. In order to make sure the aerial's pointing in the correct direction, use a compass as the aerial alignment needs to be very precise. If you have an aerial which can be raised, lift it to its highest elevation to get the best result, but if it's mounted on a pole, ensure it is adequately supported. If the aerial sways, this will disrupt the picture and sound.
Most digiboxes have a set-up page that displays two meters while scanning takes place. One of them shows signal strength and the other shows quality. The quality meter is the one that needs to register as high as possible for good results.
A high-quality reading, even with low power, will give good results. If you can't get this, try one of the other transmitters on your list and choose the best.
With that done, you are ready to complete the channel scan and start watching TV.
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