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 conventional signals (analogue) all the information is broadcast for every frame of a picture for example. 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. What you actually see and hear is an analogue reconstruction of a digital signal. By nature all sound reaching your ear is analogue, the vibration of the loudspeaker cone creates an analogue sound wave, just as the tube of your television is excited by an analogue signal being presented to it and causing the tube to glow. In short a digital receiver converts digital broadcasts into analogue pictures and sounds for our viewing and listening pleasure.

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 Channel 5 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

ASTRA satellite at 28.2º 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 19.2º 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. Village Video has no control over the broadcasts and 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 terrestrial broadcasts, 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. The intention is for this to happen between 2005 and 2010, but it may happen sooner or later!