SATELLINE-3AS
User Guide, Version 2.3
91
10.3.4 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, asuse 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 cablesThe 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
·
other radio modem systems
·
PC-related devices (approximately 5 m radius from antenna)
When ordering antennas we request you to note that antennas are always tuned to a specific
frequency range. Simple antennas and antennas, which have been constructed of stacked yagi-
antennas, are typically rather broadband. As the number of yagi-elements increases the
frequency range becomes narrower.
When designing and installing a system it is advisable to prepare to test the system, and also to
consider serviceability of the system. In particular cabling should be planned to allow easy
access and to allow for maintenance. It is often practical to use long antenna cables, so that the
radio modem can be installed far enough from the antenna itself to a location that is easily
accessible (see section 10).
