Do adjust your set: it's switchover time

A NEW kind of D-Day is approaching for large swathes of Scotland's most populated areas. During late May and early June, the four television transmitters in the STV Central region that haven't already switched off their analogue signals will make the change to digital; and for Central Belt residents TV will never be the same again.

But what are the options for switching from traditional analogue televisions to more modern digital sets, and how much will it all cost?

Viewers who have satellite TV via Sky or cable from Virgin Media don't need to worry about the changeover because they already receive digital signals, as does BT Vision.

But if you don't want to pay a subscription to Rupert Murdoch or Sir Richard Branson - beginning at about 19.50 a month, plus the cost of decoders and installation - then you can still get digital TV.

There are two ways of going about this while still avoiding a monthly charge: Freeview, which uses traditional TV aerials, and Freesat, which involves having a satellite dish fitted to your home.

Freeview signals are beamed through the air by TV transmitters in a similar fashion to traditional analogue broadcasts. Depending on the age and condition of an existing antenna, some homes will need to replace their old aerials.

The cost of getting a new aerial fitted can vary considerably, but an average price would be in the region of 80. The only other cost involved should be either buying a TV set with a built-in Freeview tuner - which should now be inside all new TVs - or forking out for a set-top box to connect to your existing TV through a Scart cable. Prices for Freeview boxes start from around 18.

Freeview offers viewers about 50 TV channels and a further 24 radio stations. Scotland on Sunday readers in the STV North and Borders television regions, which have already made the switch to digital TV, have reported greatly improved reception following their switchovers.

The new digital technology also offers a range of other services. For example, Freeview HD allows viewers to watch certain channels in high definition.

Either an HD-ready TV, with 720 rows of pixels, or a Full-HD TV, with 1080 rows of pixels, will be needed to get the most out of high definition, the same quality offered by Blu-ray disc players.

In addition, Freeview+ boxes have built-in hard disk drives that allow single programmes or whole TV series to be recorded at the touch of a button. The electronic programme guides, which are accessed by pressing a button on a Freeview remote control, are one of the major steps forward of the digital switchover, making it much easier to record TV programmes.

Freeview is run by a company called DTV, which in turn is owned by the BBC, BSkyB, Channel 4, ITV and communications company Arqiva.

The free-to-air alternative is Freesat, a system that broadcasts digital TV channels via satellites. Viewers need a satellite dish to watch Freesat, along with either a TV set with a built-in Freesat decoder or a set-top box decoder.

The costs of installing a satellite dish can vary significantly, with the basic set-up costing about 70, including the dish and cables.

When buying a dish, customers are asked how many LNBs they need. These are "low noise block down-converters", for the technically minded, and are the cables connecting the satellite dish to the decoder inside the house. With one LNB, normally only one channel can be watched or recorded at a time, or a limited number of channels can be viewed while one channel is being recorded.

Like Freeview, different types of Freesat boxes are available. Freesat SD offers standard definition channels, while Freesat HD gives access to high-definition programmes.

Freesat+ lets you record one channel while watching another, if you have two LNBs coming off your satellite dish, because it has two tuners built into its decoder.

Freesat HD and Freesat+ also allow you to watch programmes from the BBC iPlayer catch-up service by connecting a cable between the decoder or TV and a broadband box. The service is surprisingly simple to set up and use, and saves the family crowding round a laptop screen to watch repeats of EastEnders. ITV Player is also on its way to Freesat.

But how do you choose between Freeview and Freesat? For some the decision will be largely dictated by where they live; the net curtains may start twitching in conservation areas if you start putting up satellite dishes. But Freesat has proved popular in rural areas of Scotland where TV reception via an aerial has traditionally been poor.

Having tested both systems over the past year, I am leaning towards the Freesat set-up. The choice of channels is very impressive for the price of installation.

But some channels are missing: comedy channel Dave, which is available on Freeview, is tied into an exclusive deal with Sky, while Channel 5 spin-offs Fiver and Five US are not available on Freesat due to European licensing issues.

So it is best to check out the range of channels available on each service before making your choice and to get quotes for the cost of installing either a satellite dish or a new aerial.

Once you make the switch to digital, you'll notice a big difference, especially if you start watching the new high-definition services. A night in with the gogglebox just became a whole lot more appealing.

• For impartial advice on the digital switchover, visit www.digitaluk.co.uk; for more information about the free-to-air services, visit www.freesat.co.uk or www.freeview.co.ukChangeover dates

Central Scotland, Bute & Argyll - 11May

Lothians, parts of Edinburgh & Fife - 1 June

Glasgow, Central Scotland, rest of Edinburgh - 8 June