4-9
z
If there are parapets around the building top and the parapet height is less than 1200 mm (47.24 in),
fix one point of the pole to the parapet with one expansion bolt and the other point to the building
top surface with another expansion bolt, and fix the directional outdoor antenna onto the pole with
pole-mounting brackets (see the right diagram in Figure 4-10).
z
If there is no parapet around the building top, first use expansion bolts to secure the pole vertically
on the building top surface or cement pier, and then use pole-mounting brackets to fix the
directional outdoor antenna onto the pole, as shown in Figure 4-11.
Installing an omni outdoor antenna on a pole
When installing an omni outdoor antenna on a pole, observe the following precautions:
z
The pole should be 35 to 50 mm (1.38 to 1.97 in) in diameter. Usually, a round steel with a diameter
of 50 mm (1.97 in) is adopted.
z
The top of the pole should be flush with the upper clamp, as shown in Figure 4-12.
z
The antenna height should meet the signal coverage requirement and the tip of the antenna should
fall within the 45° protection angle of the lightning rod.
Usually, no lightning rod is directly soldered onto an omni antenna pole (no metal object is allowed
within one meter in the horizontal direction of the omni antenna). Instead, a lightning rod is set on a
separate pole between two omni antenna poles and the lightning rod is high enough to keep the tip of
omni antennas within the protection angle.
Figure 4-12
Install omni antennas
45°
45°
Omni outdoor
antenna
Clamp
Antenna pole
Lightning
protection angle
Lightning rod
If the lightning rod cannot be installed on a separate pole owing to the environment limitation, the
installation method shown in Figure 4-13 can be adopted. In this case, the lightning rod pole should be
at least one meter away from the omni antenna pole.
