Cambium PMP 450 AP, User Manual

Page: 286 / 301

Chapter 6: Installation Installing external antennas to a connectorized ODU
Page 6-39
4 Choose the best mounting location for your particular application.
Note
Use the embedded spectrum analyzer or a commercial analyzer to evaluate the
frequencies present in various locations. OFDM APs need not be mounted next to
each other. They can be distributed throughout a given site. However, the 90° offset
must be maintained. If you want to collocate these APs with PMP 100 Series APs of
the 5.4-GHz frequency band range, plan to allow at least 25 MHz of separation
between their center channels.
5 Secure a ground strap to the ground lug on the back of the AP.
6 Secure the ground strap to the pole, tower, or other trusted ground.
7 The bracket of the standard antenna has provision for measured down tilt. The recommended
practice is to use one of the many radio analysis and mapping tools or on-line tools to calculate
down tilt based on antenna height above the service area.
The proper angle of tilt can be calculated as a factor of both the difference in elevation and the
distance that the link spans. Even in this case, a plumb line and a protractor can be helpful to
ensure the proper tilt. This tilt is typically minimal.
The number of degrees to offset (from vertical) the mounting hardware leg of the support tube is
equal to the angle of elevation from the lower module to the higher module (<B in the example
provided in
Figure 65).