User Manual

3 Installing the Base Station
26
The selection, routing, and length of coaxial cable are extremely important in the
installation. Buy the best cable you can obtain, route it via the shortest way to the
antenna, and keep it straight. Do not form it into sharp bends on its way. Do not use any
more cable fittings for the installation than absolutely necessary. All cautions here apply
equally to all coaxial cables in the system, both input and output.
Pay attention to radial ice accumulation when designing the transmission system. It is
not uncommon for at least an inch of ice to build up on the tower and antenna. This in
turn significantly increases the weight, cross section, and wind loading of the system.
Attaching the transmission line to the tower is crucial to maintain a safe and reliable
operation. Nylon wire ties and electrical tape will break down in the sunlight and
ultimately fail, creating a potentially dangerous situation. It is important to use proper
clamps and hoisting grips and also ensure that the transmission line is grounded at the
tower in several locations. When high currents flow through the tower in the event of
lightening strikes, some of that current will flow through the outer conductors of the
transmission lines. Due to the resistance difference between the steel tower and copper
transmission line, a significant voltage can be developed, often resulting in arcing
between the outer jacket and outer conductor, thus pitting the conductor.
Preventative maintenance is crucial in ensuring that safety is maintained. Specifically,
check that transmission line grounds are tight and are not missing any hardware.
Frequently inspect support clamps or spring hangers. Consider investing in an ice
break, if you haven’t already done so, as shards of falling ice can damage the
transmission line. Check the tower light photocells and conduit.
The better-known tower manufacturers offer complete technical and safety
documentation with their towers. Be sure that you have this information as it regard
wind loading, guying, etc. The best-designed antenna system will function poorly if
shortcuts and compromises are used during installation. Follow the manufacturer’s
instructions exactly, along with an engineering data prepared for the site. Be absolutely
safe and certain about this aspect since human lives may be at stake.
Electrical Service Recommendations
We recommend that a qualified, licensed local electrician be consulted for the required
electrical service. We suggest local electricians because they know the local codes,
they can be on site readily, and you are apt to get better overall support if you use local
suppliers.