LightPointe AireLink 60, Installation And User Manual

Page: 77 / 133

AireLink

60 Installation and User Manual Rev. D System Installation
Page 77
7. The alignment tool is meant to provide a rough alignment towards to opposite antenna location.
It is however not an exact tool for finding the best alignment of the antennas. This is done via
the digital voltmeter.
8. Turn the Azimuth and Elevation Adjustment Screws at each antenna left/right for best azimuth
alignment and up/down for best elevation alignment and observe the voltmeter reading. The
goal is to find the maximum RSSI voltage reading on both sides of the link. Using a meander-
like scan pattern has proven to be the most efficient way to align the antennas. This is illustrated
in Fig. 5-16.
Figure 5-16: Antenna alignment scan
Do NOT move both radios at the same time. Try to optimize the RSSI signal
level first at one side and then repeat this process at the opposite side.
Communicate changes in signal levels during the adjustment process to the
person at the opposite side via a two-way radio or cell phone.
Ensure that the antennas are not aligned on a side-lobe. In particular when the system is installed
over short distances the side-lobes can be easily seen. Rotate the antenna a few degrees to each side
of the perceived alignment center and both side-lobes can be detected as “local RSSI voltage minima”.
The main lobe which is located right in the middle between the two side lobes will have a much higher
voltage reading. Fig. 5-17 shows a simple illustration of the alignment process and the location of the
antenna side lobes in relation to the main lobe.