Digital TV & Radio

Most people associate digital television with pay services such as Sky. Digital television and radio is much more than this.

Digital, to use a generic term, is just a broadcast system. With analogue signals (what was used before switch to digital) all the information is broadcast for every frame of a picture. With digital, information that is the same only needs to be sent once and the computer in the receiver sorts this out and reconstructs the picture and sound, or just the sound track in radio.

It doesn’t stop there either. The broadcasts can be received in several ways.

Through your TV aerial - terrestrial
Via a satellite dish
Underground cable (if you live in a cable area)
Down your telephone line (new technology not available in most areas)

As aerial and satellite system installers, we are only concerned with the first two.

The main TV operators, BBC, ITV, Channel 4 and FIVE provide terrestrial digital services. These services are free to view with a digital DVB television or terrestrial set top box. Providing you are in a DTT coverage area these services only require a normal, good quality TV aerial system to be able to receive them.

The terrestrial services are also available from the Freesat platform of the ASTRA and Eurobird satellites at 28.2 °E. It is from this position that SKY broadcasts its vast array of channels to cater for all tastes. In order to receive signals from the satellite a small dish is required, which must have a direct line of sight to the satellite. Dishes do not have to be mounted on the front of properties (see our section hidden/discrete installations). Digital quality radio is also available from the satellite along with audio channels with no adverts, jingles or disc jockeys – it’s just like listening to your favourite music on CD.

Digital satellite does not stop with SKY. The European satellite operator, Eutelsat, has several satellites in orbit above us broadcasting many thousands of channels in all languages. ASTRA also operates a satellite service at
19 °E, broadcasting German, French, Dutch and many more channels. Some of these services are encrypted and only available in the country for which they are intended whilst others are free to air. TV and Satellite has no control over the broadcasts and does we are not involved with the supply of cards for programming other than SKY. The monthly magazine ‘What Satellite’ gives a very good listing of all digital satellite services available in the UK.

Finally, it is the government’s intention to switch off all analogue television broadcasts by 2012, and use the more broadcast efficient digital service. One digital channel space can carry many programmes, whilst the same space can carry only one analogue programme.