Digital aerial, HD Digital aerials, Freeview digital aerials

Three things need to be taken into consideration:

• Where you position the aerial (outside or inside) including the direction it points to
• The location where you live. There is a particular type of aerial suitable for reception of your area, known as the Group
• The type (or design) of aerial you choose

Aerials are divided into groups, classes and gain (strength of signal)

Groups (CH = channels)

• Group A - CH21-CH37
• Group B - CH35-CH53
• Group C/D - CH48-CH68
• Group K - CH21-CH48
• Group E - CH35-CH68
• Wideband - CH21-CH68

These groups are area specific except 'wideband' which is anywhere in the country.

Aerials can be identified by the end cap, the colour is unique for each group:

If you want to know more about your local transmitter, including the group it is within click here

Gain
The more elements an aerial has the more gain it has. Generally speaking there are low gain, medium gain and high gain. If an aerial has 18 or more elements it is classed as high gain. The higher the gain the stronger the signal that is passed to your receiver (TV or set-top box).

You have to be careful that you do not provide too much gain, for instance if you live in an area that requires a Group "A" aerial, although you can use a "wideband" aerial you cannot use a high gain wideband aerial. If in doubt consult a professional installer and ask his advice.

HDTV Specific Aerials
Now we think that this is going to be a hot topic in the very near future. HD Digital Aerials are likely to come onto the market. But will they just be a selling hype? What you really need is a good quality aerial. designed for your "group" (see above) and we can't emphasise enough - the best quality aerial cable. It is like getting the fastest broadband internet available but then buying the cheapest wireless router to carry your connection. Quite simply, you won't be getting the most out of the product.

So when Freeview HD is introduced on December 2nd, 2009 to areas that have already been switched over to digital - we will possibly see a quality issue with Freeview HD on some installations.

So in conclusion, if your aerial has been on top of your roof for many years and it is the original cable - then, it may be time to replace it. But don't rush out and buy now, wait for HD to come to your area and make your decision after you have tried it.

Outside aerials mounted high up on a roof give the best reception and are the preferred method of receiving your favourite digital programmes. However the main drawback is that for most people the only way to get it installed is by a professional aerial installer. We would recommend that you always hire a professional installer for these reasons:

• He (or she) can give you specific advice on the best aerial for your area or situation
• It is the safest way. They have much experience and the proper equipment to climb to the top of your house
• They have electronic devices that tell them where to point the aerial
• If things are not quite right with the installation you can get them back to fix it
• They are insured - you are not!

Have you been involved in the past on a "family" project of setting up an aerial?. We would like you to imagine this scenario: Dad's on the roof, the son or daughter conveys messages from Dad to Mum, who is checking the quality of the picture on the TV. Her message is conveyed back to Dad... and so on. Dad is getting frustrated and cold ... Does it sound familiar?

Well these professional installers can do all of this on their own. From the roof they work their magic with a meter, some of which can display the data for each channel and indicate a pass or fail. Others display the actual programme being broadcast - how clever is that?

Inside Digital Aerials

Loft Aerials
Loft aerials are very convenient and relatively much easier to install than roof-top aerials. However there is problem with installing a loft aerial - they suffer from loss of signal strength.

Here's why, because the aerial is shrouded by the roof which consists of tiles, slates and felt, some of the signal strength is lost as it passes through these materials. It can be reduced as much as 10% - 40% which in a medium to low signal strength area, could mean loss of picture, or the picture 'freezing' or breaking up.

If you are choosing a loft aerial, so as to save money, you may need to think again, as it could be false economy. If you were to ask an installer to supply and fit a aerial in a loft, the cost would not be much different than fixing an aerial to a chimney. After all most of the cost is not the aerial but the installers time.

Set-top Aerials
Set top aerials are a very convenient way to quickly set up your digital Freeview box. But you may wish to consider the following:

In the (old) days of the analogue set-top aerial, they were to say the least temperamental - a car would pass by in the road and the picture would distort or go fuzzy. Often though you would settle on a position that would give you good reception on one or two channels and average on others.

It's not the same with aerial Digital reception, you either get a picture or none at all. You may be able to get one channel, but not another because channels are broadcast at different strengths. Eventually when everyone has been switched to Digital (2012) the strength of the signals will be increased, but that is a long time to wait if your set-top aerial is not up to scratch.