19
Maintenance and Troubleshooting
5
Maintenance and Troubleshooting
Precautions
WARNING
Don't expose personnel to the medical hazards of intense radio fre-
quency (RF) radiation. Whenever working on the tower in the area of
the antenna, turn off all transmitters and lock them out so that they can-
not be turned on accidentally.
Maintenance log
Shively recommends that you keep a maintenance log, recording important
performance parameters such as VSWR readings, de-icer current draw, main-
tenance done on the tower and the antenna, and severe weather events. This
information can be valuable for identifying and solving problems.
on page 22 shows a suggested log form.
Physical inspection
The antenna system should operate for years if properly installed and main-
tained. Shively Labs recommends that as a minimum, the antenna should be
physically inspected
at least once a year
.
In addition, inspect the antenna after severe weather events, and after climb-
ers have been on the tower working on equipment above the antenna.
In addition to checking the general condition of the antenna and coax:
• Replace dented, broken or bent components.
• Inspect radomes for cracks and plugged drain holes.
• Re-tighten all hardware, hose clamps, and U-bolts to installation
specifications.
• Inspect hose clamps and U-bolts carefully for signs of wear or
fatigue caused by vibration or tower movement.
Paint
The radiators should never be painted (a coating of paint affects VSWR), and
they need no surface protection, since they are made of copper and brass.
This includes Teflon or other "ice-prevention" coatings.
It is not necessary to paint the feedline, although no harm will result from
doing so.
Radome removal and
reinstallation
If it becomes necessary to remove a standard radome to gain access to the
radiator, first remove the radiator as described above and bring it to the
ground. If the antenna is to be operated without that radiator, be sure to
observe all precautions.
On the ground, merely remove the ten bolts that secure the radome halves
together, and the four additional 3/8” bolts securing the formed channel to the
radome backplate, and lift the radome away from the radiator. Reinstall the
radome and the radiator in the reverse order of removal. Re-seal the radome,
using Dow Corning 732 Multipurpose RTV or equivalent.
WARNING
Maintenance should be
performed only by per-
sonnel experienced in RF
systems and familiar with
this equipment.
Important
Give your antenna a full
inspection at least once
per year!
