Many household still have the old analogue television aerials giving them a very poor
freeview reception and a small upgrade with vastly improve the picture quality to your TV.
Choosing Digital Aerials for a Better TV Freeview Reception
In todays digital world many households are now receiving TV transmissions through Freeview and Digital Set Top Boxes but many of the old analogue television aerials are not suitable or practicle to receive the higher grade digital TV transmissions and therefore have to be upgraded to meet the new standards and specifications required. The technical reasons behind this incompatibility of the old aerials compared to good digital TV aerials is to do with the transmission frequencies and bandwidth of digital TV services compared to the old analogue television aerial signals and these are different within UHF and DTT (DVB-T multiplexes) band transmitting frequencies and capabilities.
Using a wideband aerial (Digital TV Aerials) is the accepted method to obtain both digital tv and analogue television services as they have the capability of receiving both transmitted frequencies so a wideband aerial upgrade is the solution for most households if digital tv reception is a required.
Standard TV Aerials (Analogue) vs Digital TV Aerials
A standard television aerial, widely known as a Yagi type aerial. This is normally mounted on the roof of a house, via a length of pole, and the aerial is made from a metal rod with a reflector unit on the back and a number of spikes or fin elements (usually 12 to 26) spaced equally on the main length of the metal rod. These aerials are designed to work optimally when they are directed towards the transmitter (directional) however the reception quality is also increased by a Yagi aerial that incorporates more of the fin elements resulting in a longer length of aerial.
The standard Yagi type aerial is found on most house roofs and is the standard type aerial used for receiving an anologue TV signal. So, if you have one of these aerials then it is more than likely that you will need to upgrade in order to receive good digital and freeview reception but most of the standard Yagi type aerials will function and receive lower quality digital reception if you are located in a good reception area close to a transmitter.
These standard Yagi type aerials are made to receive groups of Frequency Transmission
(Groups A to W) - see diagram below.
Upgrading To Digital High Gain TV Aerial
Where a lower reception in a poor signal area is problematic then you will need to consider a Digital High Gain Aerial upgrade. These High Gain Aerials have an additional reflector unit (2 reflectors) on the rear of the aerial and have more fin elements even upto 80 of them on the rod or the main front component of the aerial. However, you will only need to consider a digital high gain tv aerial in poorer reception areas or where you live a long way from a transmitter. In relation to freeview reception these aerials will greatly improve a digital signal and in most cases where a digital tv reception is difficult to get, through a low strength reception, then a good quality digital high gain aerial will allow you to receive digital TV previously impossible with a conventional aerial.
There are accepted standards of televsion aerials, rated by the CAI (association of TV aerial installations) - The highest standard is (1) and for homes that are on fringe recptions areas, rate (2) is for a middle reception areas and rate (3) covers good reception areas. All of these aerial ratings are available in different digital TV aerial types including high gain, wideband or selective frequency aerials.
Loft Mounted Digital TV Aerials
It is not recommended to install a digital aerial (freeview aerials) in your loft space as there may well be interference possibilities from electrical, plumbing and even roof tiling all of which may cause interference and degredation of the digital tv signal reception. However, you can also get cable upgrades such as satellite cabling to replae the aerial cable or even place a powered TV signal booster (freeview booster) between the loft aerial and the television to compensate for any degradation of freeview reception caused by aforementioned problems in a roof space installation.