Aerial Elements
Most aerials used are of the Yagi type consisting of a main
boom with several straight rods across it. The more rods (elements),
the higher the gain and the sharper the aerial directivity
becomes. In areas with a strong signal a Yagi with between
10 and 18 elements will generally give good results. For areas
with weaker signals a high-gain
aerial with mast-head amplifier
(booster) may be required.
Channel Group and
Polarisation
The receiving aerial must match the channel group used by
the transmitter serving the local area, point towards the
transmitter, and be in the same ‘plane of the polarisation’.
The commonly used ‘Yagi’ aerial should be mounted with the
rods horizontal to suit horizontally polarised transmissions
(all main transmitters) and vertical to suit vertically polarised
transmissions (most relay transmitters).