GDS C1, Инструкция по эксплуатации

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7.5.4 COAX CABLES
If a coax cable connects to the antenna via connectors, it is very important to
weatherproof the connection using our 1000-2314 or equivalent sealing tape. Moisture
ingress into a coax cable connection is the most common cause of problems with antenna
installations. A three layer sealing process is recommended – an initial layer of electrical
PVC tape, followed by a second layer of self-vulcanizing weatherproofing tape (1000-
2314), with a final layer of electrical PVC tape.
Allowing a drip “U loop” of cable before the connection is also a good idea. The loop
allows water to drip off the bottom of the U instead of into the connection, reduces
installation strain and provides spare cable length in case later the original connectors
need to be removed, the cable cut back and new connectors fitted.
Avoid installing coax cables together in long parallel paths. Leakage from one cable to
another has a similar effect as mounting an antenna near another antenna.
7.6 SURGE PROTECTION & GROUNDING
Voltage surges can enter the C1 via the antenna connection, power supply connection,
connections to other equipment and even the “earth” or “ground” connection. Surges are
electrical energy following a path to earth and the best protection is achieved by
“draining” the surge energy to earth via an alternate path. Wireless devices need to have
a solid connection to earth via a ground stake or ground grid if the soil has poor
conductivity. Solid connection means a large capacity conductor (not a small wire) with
no coils or sharp bends. All other devices connected to the C1 need to be grounded to the
same ground point. There can be significant resistance between different ground points
leading to very large voltage differences during lightning activity. As many wireless
units are damaged by earth potential surges due to incorrect grounding as are direct surge
voltage.
It is very difficult to protect against direct lightning strikes but the probability of a direct
strike at any one location is very small. Unfortunately, power line surges and
electromagnetic energy in the air can induce high voltage surges from lightning activity
several miles away.
7.6.1 ANTENNA GROUNDING
Electromagnetic energy in the air will be drained to ground via any and every earth path.
An earth path exists between the antenna and the C1 and to protect against damage this
earth path current must be kept as small as possible. This is achieved by providing better
alternate earth paths. It is important to ground the antenna to the same ground point as
the C1. Antennas are normally mounted to a metal bracket which should be grounded to
the C1 earth connection. Surge energy induced into the antenna will be drained first by
the mount’s ground connection, second by the outside shield of the coax cable to the
ground connection on the radio and third by the internal conductor of the coax cable via
the radio electronics. This third earth path causes damage unless the other two paths
provide a better earth connection allowing surge energy to bypass the electronics.