SATEL-EASy+
User guide
Version 1.33
80
rooftop or the engine hood or trunk door are usually suitable). In problematic cases the most
suitable type is a ½-wave antenna. It can be installed directly at the top of a pipe with the added
benefit of gaining as much as free space around the antenna as possible. In case the antenna
cannot be directly connected to the radio modem, a coaxial cable with 50-ohm impedance must
be used between the antenna and the antenna connector.
16.3.3 Base stations
• Omni-directional antennas (¼-, ½- or 5/8-wave antenna)
• Directional antennas (Yagi /multi-element antenna or corner antenna)
The antenna should be installed in a vertical position. The exact location of the antenna
depends on several factors, such as the size of the overall system and the coverage area terrain
contours. A rule of thumb is that the base station antenna should be located at the highest point
of the coverage area and as close to the centre of the coverage area as possible. The base
station antenna can also be located inside a building, if the walls of the building do not contain
metal.
16.3.4 General antenna installation instructions
The reliability and the achievable coverage of useful signal strength can be severely affected by
the positioning of the antenna. Antenna and cable connectors should have gold-plated pins and
sockets, as use of low quality connectors can lead to eventual oxidation of the connector
surfaces, which in turn may degrade the contact and cause additional attenuation. Good quality
tools and materials must be used when installing radio modems, antennas and cables. The
weather tolerance of the materials used must also be taken into account. Installed materials
must withstand all foreseeable weather conditions (frost, excess sun, direct UV-radiation,
seawater etc.). Also, possible environmental pollution must be considered (acids, ozone etc.).
Antennas must be installed well away from metallic objects. In the case of small antennas this
distance should be at least ½ m. With large antennas the distance should be >5 m and in case of
repeater antenna combinations >10 m.
If the system contains a large number of radio modems, the best location for an antenna is the
highest point of a building and possibly an additional antenna mast. If a separate antenna mast
is used, the antenna can, if necessary, be installed sideways about 2…3 m from the mast itself.
When installing an antenna possible interference sources must be considered. Such interference
sources are, for example:
• mobile telephone network base station antennas
• public telephone network base station antennas
• television broadcast antennas
• radio relay antennas
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