Installation
2.1.4 Installing and earthing antennas
You must connect an antenna to each module using the SMA connector at the top of
the housing.
Weidmuller recommends carefully taping the connections between the antenna
and coaxial cable to prevent moisture ingress. Moisture ingress in the coaxial
cable is a common cause of radio system problems as it greatly increases the
radio losses.
ATTENTION
Tape the connection with three layers of tape:
Layer
Tape
1 PVC
tape.
2
Vulcanising tape (e.g. 3M 23 tape).
3
Additional layer of PVC UV-stabilized insulating tape.
The first tape layer lets you easily inspect the joint if required as you can easily
remove the vulcanising seal.
You must effectively earth all masts for mast-mounted antennas to avoid
lightning surges. We also recommend using a coaxial surge diverter for
antennas mounted outside industrial plant environments.
DANGER
If the antenna is not already shielded from lightning strike by an adjacent
earthed structure, you should provide shielding by installing a lightning rod
above the antenna.
You should connect the antenna to the module using 50 ohm coaxial cable (e.g. RG58
or RG213) terminated with a male coaxial connector, The higher the antenna is
mounted, the greater the transmission range; however as the length of coaxial cable
increases so do cable losses. For use on unlicensed frequency channels, there are
several types of antenna suitable for use.
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