In some rural areas, especially hilly parts, satellite transmissions are the only way to get a digital television signal in a country that has now switched its analogue TV transmitters off. Fortunately, since the launch of Freesat in 2008, British consumers now have the option of buying a satellite receiver and tuning into free-to-air channels that had previously been the preserve of terrestrial and cable broadcasters.
Buyers must be aware of the main factors to consider while preparing to make a purchase by focusing on two categories. One is outside the house and concerns questions such as how to find a satellite signal and whether there are any local climatic, topological, or planning issues that might influence the choice of dish. The other is indoors. Buyers need to anticipate the number of required feeds. Modern receiver/recorder boxes require multiple feeds, so choosing a fitting that provides the right number and type of outputs is important. Buyers with knowledge of the aforementioned topics are well on their way to finding a new satellite dish to suit their needs.
Anatomy of a Satellite Dish
For people considering installing a dish in person, it should be stressed that aligning the dish to the satellite needs to be done with precision. Even small errors of about a degree or so can result in serious signal degradation, so it is important to be equipped with some knowledge of the elements of satellite dishes and their alignment.
The important components making up a satellite receiving array are the dish, the feedhorn, and the converter. The fixtures and fittings are important too, but the working parts comprise a parabolic dish, which is shaped to reflect microwaves across its surface to a single focal point. The feedhorn is mounted at that focal point, and it functions like the eyepiece in a reflecting telescope and funnels the incoming signal to the low-noise block downconverter (LNB). Where these two functions are fused, as they typically are in current designs, a single abbreviation, LNBF, is used.
Finding a Satellite Signal
There is a cluster of satellites at the same nominal position, 28 degrees east of the Greenwich meridian. There are four Astra satellites at 28.2 degrees and one EuTelSat at 28.5 degrees. Previously, the EuTelSat was also called Astra and had subsequently been renamed Eurobird, so some confusion about the name is possible. This cluster of satellites handles BSkyB and Freesat transmissions to the U.K., so a dish that has been aligned for one of the services can easily be changed to the other.
As well as the Freesat service, BSkyB have their own free-to-air service as an alternative to their monthly subscription packages. The programming available on BSkyB’s free service is similar, though not identical, to that offered by Freesat. Since receivers cannot switch between the two, it is necessary to make a choice one way or another, or else to install a second dish.
To find out about other satellites that might be visible from British locations, there are a number of websites that show satellite beams graphically, along with a host of other useful information. Among the satellites serving Europe are the Nordic Thor and the Spanish Hispasat.
Satellite Dish Design
Most satellite dishes come in one of two configurations. Either they are near-circular, or else they have a pronounced oval shape. The so-called "squarial", pioneered in the early days of British satellite broadcasting, has long been obsolete. Performance is more affected by surface area than by shape although the oval design has advantages when it comes to picking up multiple satellite signals.
Satellite Dish Size
Most domestic satellite dishes are between 43 and 80 centimetres across and are normally fixed to a single alignment. Among the issues to consider when selecting a size are the aesthetics and possibly local regulations, but larger dishes do perform better because they are less vulnerable to rain fade and interference. Rain fade is a phenomenon in which rain dissipates the microwave signal as it passes through the cloud mass and precipitation between the transmitter and the ground.
Alternative Satellite Dish Types
There are alternatives to the fixed single satellite dish. Some, notably the motor-driven type, are an older technology. The other approach, setting up multiple dishes, is a crude but effective alternative.
These dishes are mounted on a pole that is geared to a motor, and they can be remotely controlled and turned to face the required satellite position. They are more popular with hobbyists than with the general television watcher.
Some designs make it possible to receive simultaneous transmissions from multiple satellite positions without the need to move the dish. These designs combine parabolic and hyperbolic surfaces, which enable the focal point to move across the primary surface while the secondary surface corrects any astigmatism. Dishes designed to receive multiple satellite signals are therefore more oval, whereas single-signal reception is best handled by a round shape. They also require a different type of LNB.
There are several types of LNB available, and the right one to choose depends on the service the satellite dish is being selected for. Assuming that the vast majority of British buyers intend to tune into BSkyB or Freesat, the most common LNBs are single, twin, quad, and octo Universal LNBs. The difference between them concerns the number of outputs provided. To run two satellite boxes from the same satellite dish, at least one feed is needed for each box.
For receiver/recorder boxes, such as the Sky+ or the Foxsat Freesat receivers, two feeds are necessary in order to record and view simultaneously. Therefore, to run two of these boxes, a quad feed is needed. Such boxes can be used with a single feed, but a choice has to be made between using it to view live or to record.
To receive signals from two satellites using the same dish, what is needed is not a twin LNB but a Dual LNB. However, attempting to use two satellite feeds simultaneously means that neither feed will be optimal, and other factors, such as bad weather, that affect reception can have double the impact. Look for LNBs that are compatible with offset focus, or oval, dishes.
Fitting a Satellite Dish
People who live in blocks of flats or tenements, in conservation areas, or in listed buildings, may need planning permission in order to mount a satellite dish, and this should be obtained prior to purchase. Installation of a satellite dish and its cabling is not difficult, provided that the proper tools are available and they are in the hands of a competent operator. Electronic expertise is not necessary although aligning the dish to a satellite signal can be troublesome.
Care should be taken to ensure maximum safety at all times, especially when remote mounting is necessary. Make sure that there is no time pressure that might prompt shortcuts and that weather conditions are favourable for a reasonable period of time.
Finding a Suitable Mounting Point
The satellite dish needs to be mounted in a location that gives a clear and unimpeded view of the south-eastern horizon. Any obstructions, whether trees or buildings, diminishes the signal. Generally speaking, the higher the better, and that is where remote mounting comes in, meaning simply that the dish is mounted on a pole that extends up and away from the roof.
At this point, an approximate alignment to the target satellite should be enough to progress to the next step, but a mounting that is fixed to the roof is easier to adjust than one mounted on a pole. The next step is to run coaxial cable to the dish from the approximate location of the receiver. One tip is to do a dummy run with a ball of string in order to ensure that the correct length of cable is purchased. Joins between shorter lengths can cause the signal to degrade. Do not switch the receiver on until the dish is fully connected to it.
Aligning to the Satellite
As mentioned previously, accurate alignment is essential for satisfactory reception. Two tools are needed: a compass, to find the right alignment, and a satellite finder to fine-tune and find the optimal position.
It is handy to have an accomplice at this point, given that the satellites are clustered in similar locations. Ask them to notify you when the correct satellite has been found. Finding the correct elevation can differ between dish designs and also by latitude, so it is not just a question of pointing upwards: Refer to the manufacturer’s instructions for detailed guidance.
Buying a New Satellite Dish on eBay
For people looking for a simple satellite dish in order to receive standard British digital broadcasting, there are normally plenty of options available in eBay’s listings. If you are a hobbyist looking for something a bit different, then you may need to dig a bit deeper and be more specific with your search terms. Either way, the place to start is on eBay’s home page with a simple query, such as "satellite dish". From the way the search results are organised, with options to filter, you can home in to likely areas.
LNBs can be found listed separately. Filtering options include brand, number of outputs, and compatible dish focus. Many listings do not specify compatibility, but for oval dishes it important that the LNB is of a suitable type.
As well as complete items, eBay’s listings also feature all the components that you might need in the event of a repair or upgrade and all the tools that you are likely to need to complete the fitting, including "satellite finders" or "signal finders". Note that "finder" is a more effective search term than "detector". You can end up paying a lot for a "compass", and it might be worth trying to find a mobile phone app that does the job before committing to a purchase.
Setting up a satellite dish can be a daunting prospect. Even though they are essentially simple devices, they are at the end of a vast and intimidating chain of up-to-the-minute technological know-how. Equipped with the right tools and materials and given a reasonable level of DIY skill, there is no reason why an installation should not go smoothly.
Before making a purchase, then, the chief issues to consider are twofold: On the outside, make sure that the dish can be oriented towards the desired satellite broadcast without impediment and ensure that the chosen dish complies with any local building regulations that might be in force. On the inside, match the dish’s capabilities to the functions required. A multi-site dual signal set-up requires a different LNB when compared to a simple, single-service, live viewing only arrangement. Finally, remember that eBay’s listings offer the full range of equipment from complete new satellite dishes to components and accessories, as well as the tools that might be needed to ensure a perfect installation.