There are some myths and misinformation about TV aerials that are put about by many people - from the media to installers. Here we will try to dispel these myths.

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.

We are experiencing a lot of difficuty in obtaining Freesat SD boxes at the moment.

We have checked with our trade suppliers and high-street stores and there appears to be a nationwide shortage of these set-top boxes. Some retailers have some stock but levels are very low and do not appear to be being replenished very quickly.

It is unclear whether there is an (as yet) un-announced policy of withdrawing these boxes from the market or whether it is just a manufacturing/supply issue.

For the time being we will only be able to provide Freesat HD set-top boxes or Free-to-air set-top boxes.

If you have a flatscreen TV that is a few years old you may find you have problems using it with newer HD equipment such as BluRay players, SkyHD set-top boxes and so on.

This is because older HD-ready TVs are not HDCP (High-bandwidth Digital Content Protection) compliant. HDCP-compliant devices were released on the market in 2008 so any flatscreen TV purchased before then is likely to have problems with newer HD equipment.

Sometimes, although thankfully it's quite rare, an HDCP device and non-HDCP device will not talk to each other at all and it will not be possible to get a picture to show on the TV. Often, however, the HDCP device is configured to only show non-HD video to non-HDCP TVs.

What this means is that if you buy a BluRay player or get SkyHD for your pre-2008 flatscreen TV you won't really be enjoying true HD content but just plain, old standard definition content.

There are three solutions to this problem - either a new TV, a device called an HDCP stripper or a device that converts the HDMI to a non-HDCP connection such as component video. Neither the new TV or the HDCP stripper are cheap options but converting the HDMI signal can be achieved for about £75 by using an HDFury. The only requirement is that your TV has component video inputs.