When you need to mount your aerial in your loft space, then in most areas you will be limited as to which TV aerial to choose for the installation. There is a noticeable difference in both signal strength and interference when installing an aerial outside a building. With the advent of digital TV the transmission is now wide band and the need for a strong signal with low interference is needed more than with analogue. If possible have a TV Aerial Installer fit your aerial on the outside of your property as it gives you the best chance. However, due to building regs in your area it may be necessary to install your wide band aerial(digital aerial) in the loft.
What is also essential is an aerial meter to make sure of the best position for the TV aerial to be installed. With the meter you can read both the reception of the signal and also the level of quality & interference or noise. So when you want to receive a perfect digital TV picture from your aerial in the loft always go for a log periodic.