Shively Labs 6842, Instruction Manual Installation, Operation, & Maintenance, Page: 47 / 64

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Maintenance
10 Maintenance
WARNING
Whenever a rigger is on the tower in the area of the antenna, shut off
the signal and lock it off so that it cannot be turned on accidentally. RF
emissions at close range are hazardous.
Log
We recommend that you keep a log of VSWR readings and any other perfor-
mance notes and maintenance history for your antenna. Such a record can be
invaluable for troubleshooting.
Inspection
Whenever a rigger is on the tower for any reason, it is a good idea to have
him check your antenna for general condition, looseness of connectors and
mounts, and electrical damage.
Paint
The radiator should never be painted; this will affect the VSWR.
Return policy
When returning any material to the factory, be sure to call your salesperson
and obtain an returned materials authorization (RMA) number first. Material
may be refused and sent back to you at your expense if you don’t do this.
Troubleshooting
Broad spectrum RF noise.
This indicates that some component is not in good electrical contact with the
tower. Make sure mounts are tight, that tower paint has been removed from
under the mounts, and that components of other systems are likewise in good
contact with the tower.
High VSWR
This is caused by any factor that changes the impedance match between the
antenna and the transmitter. Look for:
• Defective RF connector. Make sure connectors are in good shape,
and that center pins are not bent over.
• Damage to any antenna components.
• Paint on radiators.
• Ice buildup on radiators.
• Interference from other tower components, especially components
broken by wind or ice.
Change in coverage
This may be caused by the same factors that can cause high VSWR. Look for
VSWR changes as well.
Do recognize, however, that apparent changes in coverage may be due to sub-
jective factors or faults of the receiving equipment. Before doing more than
checking the VSWR, be sure that an actual coverage change has occurred.