Something that only cost a few pounds can't really make a difference, right? This is the exception. My Sky Signal Strength was about 1/3 on signal strength and 2/3 on signal quality. After using the amplifier, I now have 3/4 signal on both. No external power is needed for the amplifier as it takes what in needs from the LNB aerial lead. You do need to purchase a Male to Male Satellite Coaxial Cable (about the same cost as the amplifier on Amazon).
Highly recommended - even if it doesn't work for you, you will have only wasted a few pounds but for me, an excellent buy.