Appendix 7

Aerial selection

If the direction and source of the interference is known, a change of aerial may reduce the level of the interfering signal. sufficiently to provide interference free reception.

When selecting an alternative aerial do not automatically select an aerial with higher gain. Check the manufacturers specification first.

As can be seen from the illustrations below the polar diagram of a high gain aerial will consist of side lobes, one of which may provide gain in the direction of the interfering signal. Changing the aerial type to one with a lower gain and reduced side lobes will reduce the interfering signal.