Astra is the name of the satellite system delivering thousands of channels to homes across Europe. The satellites are owned and operated by SES, a global company operating in video distribution for 30 years and based in Luxembourg.
The Astra satellites are all in geostationary orbit some 36,000km above the Earth’s equator, and from the ground they appear to be fixed in the sky (although they cannot be seen with the naked eye). The satellites are arranged with one or more satellites in each of five orbital positions across the sky above Europe.
Your dish can be fitted with two LNBs (the device at the front of the dish that picks up the signals collected by the dish reflector), positioned on the dish to receive the signals from two different orbital positions. A special switch at the dish, or in the set-top box selects between the signals from the two positions. The idea can be extended to three or more satellite positions by adding further LNBs or by using a motorized dish to turn to face the different satellites as required. You can get advice on receiving signals from two or more satellite positions from a specialist dealer or installer.
Theoretically you can use a cable length of up to 100 metres with the highest quality cable but this does depend on the set-top box and the LNB (the device at the front of the dish that picks up the signals collected by the dish reflector). In most cases, about 50m is the longest length for reliable reception but longer cable lengths can be accommodated using a special amplifier (a ’line driver’). A dealer or installer will be able to advise you on this.
You cannot see the Astra satellites because they are so high in the sky. However, the dish is accurately aimed at a satellite by measuring the signal received and adjusting the aim to maximise the signal. Although many set-top boxes include a signal level display, using a separate meter, designed for the job, is usually the most accurate and quickest means to align the dish.
The satellite signals, even those from the high-power Astra satellites, are quite weak when they reach the Earth and can be stopped by almost anything in their path – even leaves on a tree, and certainly by brick or wooden walls and glass – so the dish must be placed outside the building to receive the signals.
Your satellite dish can be positioned anywhere it will have a clear ‘line of sight’ to the satellite(s). Usually, this means fixing it high up on a wall of the building, clear of people, vehicles, etc that could obstruct the signal. However, your dish can also be positioned near ground level in the garden if there is nowhere else suitable. A local installer will be able to advise on the best place for the dish.
You can install a satellite dish antenna yourself. You will need the means and skills to fix the dish to your home in a suitable position (with unobstructed line-of-sight to the satellite), a signal strength meter to help accurately align the dish on the satellite and the correct coax cable to connect the dish’s LNB to your receiver inside the home. Please note that installing a dish will usually require working at heights, which carries risk of injury.
It may well be possible to use an existing dish to receive Astra channels if it is large enough. If the dish is not pointed at the Astra satellites carrying the channels that you want to receive, then it will have to be re-aligned. If the dish and, particularly, the LNB (the device at the front of the dish that picks up the signals collected by the dish reflector) is old or in poor condition, then it may be more cost-effective to replace it. A dealer or installer can advise you about reusing a dish.
There are some alternative antenna designs available, such as flat plate antennas. However, the latest dishes for the powerful Astra satellites are very small and inconspicuous, and can usually be installed on your home or in the garden to be no more noticeable than a TV aerial. A specialist satellite dealer or installer can advise you about alternative antennas and discreet dish installation.