What do aerial filters do?

An aerial filter is used to prevent unwanted signals from reaching your equipment, whilst allowing the wanted ones to pass through unaffected.

Some filters may need to be installed before any amplification, while others should be installed directly before the receiving equipment.

A qualified installer should be able to suggest the best option for you.听


High-pass filters

Filters stop unwanted signals from radio amateurs and CB enthusiasts which can interfere with TV听and radio reception.听Since many amateur transmissions are lower in frequency than TV and FM signals, a high-pass filter听can be fitted to the receiver to prevent the low frequency amateur signals from reaching it听and causing problems. High-pass filters are a common component in what are known as 鈥楾VI' filters, sometimes听called 鈥楾ETRA' filters.

Band-Pass filters

Band-pass filters allow听only a range of required frequencies through, rejecting all others. Band-pass filters must be specified for the correct use. For example, using a television band-pass filter on an FM tuner will prevent reception of FM signals - and vice versa.

Braid Breakers

Braid-breakers work by preventing low frequency signals from reaching TV听or FM equipment down the outside of the aerial cable. If you have several听devices connected to your equipment, you may need to fit filters to the inputs of all of them.

Ferrite rings

Sometimes strong, amateur signals can interfere with audio equipment as well as TV or radio. This usually happens because the loudspeaker wires or mains cables act as 鈥榓erials' and conduct the signals inside the case. You can wind a short section of the cable in question around a ferrite ring using a number of turns, and to do so as near to the hi-fi /TV/radio as possible.

Mixed filters
Examples of filters, braid breaker and a ferrite ring

Qualified Installer

The 主播大秀 cannot recommend individual Installers. The听CAI ()听is a recognised trade body which will be able to put you in touch with one of its听members in your area.