Variable Coaxial Attenuator 0-20dB (75ohm)Overview - Decibel (dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity, usually power or intensity. This device will reduce the signal strength between 0-20dB to hopefully help you achieve a better signal quality. Compatible with;Digital (freeview) and analogue signal signalsSatellite signalsCable TVTechnical Details;VSWR - Voltage standing wave ratio is kept low to maintain signal integrityVariable Attenuator - This attenuator can be adjusted from 0 - 20dbFrequency Range - 5 - 1000MhzResistance - 75 ohm ratedHigh quality metal surround constructionHow do I know if I need an attenuator? - If you experience break-up on some or all of your channels whilst trying to tune in your TV, it could be that your signal is too strong or too weak. It will usually take trial and error to work out what the problem is. An attenuator is usually the cheapest option to establish what the problem might be. The example below is to guide you through a typical aerial installtion, this may vary if the attenuator is not being using with an aerial, however the same principles apply. If you have installed an aerial and you've done the basics such as making sure it is pointing in the right direction and you are sure that all your contacts are making a good connection then, it may also be worth looking at houses near to you, look at their aerials, if yours looks to be pointing in a similar direction and is a similar sort of aerial, it may be worth asking them if they have any problems with reception. If their reception is fine, it is likely that you have made a mistake somewhere when installing. If everything seems to be installed correctly and you are still getting problems with reception, buying this attenuator will establish whether your signal is too weak or too strong. When installed, if your signal quality deteriorates further, then your signal is too weak, if the signal goes better you should leave.