If you are still experiencing reception problems after the installation of your SLxP aerial amplifier, please refer below. Analogue terrestrial TV: A faint, grainy or snowy picture is generally caused by a weak signal. Normally the TV transmitter will be a long way away. A possible improvement could be made by reducing the aerial down lead losses, installing a high gain aerial and by adding a low noise masthead amplifier. In a small number of cases, a snowy picture can also be caused by a TV signal that is too strong. Herringbone pattern: Herringboning is generally caused by too strong a TV signal or by a local high power transmitter such as CB, amateur or taxi radio. Your TV sound may be affected as well as the picture. Using an attenuator will reduce the gain of an aerial signal and improve the overall picture.