Saturday 24 October 2009

Myth 1: You need a digital TV aerial to watch Freeview.
There is no such thing as a digital TV aerial. There are wideband aerials, grouped aerials, log periodic aerials, high-gain aerials, grid aerials and even YAGI aerials, but no digital aerials. All aerials are capable of receiving both analogue and digital TV signals and some do have characteristics that make them better for receiving a digital Freeview TV signal. However an old wideband aerial may provide a perfectly adequate digital Freeview TV signal without needing to be replaced.

Myth 2: The higher the gain of an aerial the better the Freeview picture.
A digital picture either works or it doesn’t and there isn’t much in between. This is known as ‘the cliff effect’ or ‘the digital cliff’. You either have good service or you have stops and starts, blocks and pixelating. Too much signal can be as bad as too little signal. There is an acceptable range of signal strength but this must also be coupled with a good signal-to-noise ratio (SNR). A high signal with low SNR is likely to give more viewing difficulties than a low signal with high SNR. It is an engineers responsibility to make sure that the SNR is a high as possible and that the signal strength can cope with occasional fluctuations in signal strength.

Myth 3: The TV aerial can be located in the loft or attic
For analogue this was true to a certain extent but still relied on the property being in a good signal area. For digital freeview the interference and signal loss caused by the roof and/or gable end will almost always result in a poor quality signal. Amplifying the signal will only result in amplifying the noise as well as the TV signal.

Hopefully this has helped dispel some myths about TV aerials. At Cable Guys we are always happy to help people by offering impartial, accurate information. If you have any more questions about TV aerials then please don’t hesitate to ask us.