Installation Guide

SAFEmine Ltd | www.safe-mine.com | [e-mail] 30/39
SAFEmine (part of Hexagon Mining)
Baarerstrasse 133, CH-6300 Zug
Switzerland
www.hexagon.com
4.4.5. SMA Coaxial Cable Connectors
Waterproofing connection: The coaxial cables contain a white plastic separator between the
screen shield and the center core conductor. This plastic is a dielectric material which has the
property to absorb water. SMA connectors are not sealed and thus tend to permit water entry from
rain and condensation. When the dielectric material in the coaxial cable begins to absorb the water,
the cables signal transmission capacity is severely compromised. Signal loss and bad GPS reception
are the consequences.
SAFEmine strongly recommends using sealing, so called self-amalgamating tape in order to
waterproof the SMA connections. Do not use the common vinyl electric insulation tape since it does
not provide a waterproof sealing for the connection.
Please attain to these recommendations for any SMA connection installed outside the cabin:
 Do not use electrical tape or insulation tape. They tend to unwrap by themselves and do not
provide a waterproof protection of the connection. See explanation below.
 Protect the connection with self-amalgamating or self-fusing tape instead. This seals the
connector from the environment.
 As an alternative to Heat Shrink can be used over the whole connection. In harsh conditions
it is recommended to use both the heat shrink and self-fusing tape.
Custom cable length: If the coaxial cables are being cut to length and confectioned with SMA
connectors, please attain to the recommendations of the manufacturer as well as the following best
practices recommended by SAFEmine:
 Do not use a knife to cut the cable. Damaging or scratching the shield screen or the center
core would lead to signal losses and deteriorate the performance of the system.
 Use a 3-blade coaxial cable stripper tool instead.
 Adjust the stripper tool blades to the depth as recommended by the SMA connector
manufacturer. See below for an example.
 Use solid core coaxial cables. See explanation below.
 Solder the center pin.
Solid core vs. stranded core: Although having a stranded inner conductor makes the coaxial cable
more flexible and less prone to breaking, it is also makes confectioning the cable with SMA
connectors more sensible to correct installation procedures of the center pin. Without the appropriate
tools such as a 3-blade coaxial cable stripper and especially the center pin crimping pliers, it is
almost impossible to consistently create high quality connections. Therefore SAFEmine recommends
using solid core coaxial cable and soldering the center pin to the core if you’re planning to cut the
cables to length.
Please send your SAFEmine supporter the datasheets of the cables and SMA connectors prior to
installation in order for assistance.
4.4.6. Antenna Cable Conduit
Through-hole mount antennas are delivered with an at least 30cm long cable conduit sleeve to
prevent the antenna cabling to brake due to repeated bending fatigue when vibrating. The installation
of the cable conduit is compulsory for every SAFEmine CAS installation using through-hole
antennas. The correct installation will ensure the robustness of the CAS system. To do so please
attend to the following rules: