User's Manual

Exalt Communications, Inc.
Exalt i-Series Installation and Management Guide
5000001 64
2007-04-15
Antenna Alignment
Antennas must be installed at both ends of the planned link to commence precision
alignment. Refer to the Exalt white paper, Antenna Alignment.
Antennas are typically aligned using the radio hardware for precise alignment. However,
there are many very useful tools available to aid in this process, inclusive of devices
specifically designed for the purpose of aligning antennas. Some examples are:
• XL Microwave Path Align-R
• Teletronics 17-402
Use of these devices may be extremely advantageous as compared to using the radio,
because they employ many unique facilities to aid in this process. Using these tools also
makes it possible to align the antennas before the radio equipment is delivered. However,
many installers successfully use the radios as the means for antenna alignment.
There are two primary facilities when using the radio to align the antenna:
• RSL voltage test point using a volt meter (recommended)
The RSL test point DC voltage is inversely proportional and numerically calibrated
to the received signal level. The voltage rises as the antennas are less in alignment,
and falls as antennas are more in alignment. The voltage measurement corresponds
to the received signal level in measurements of dBm (a negative number for RSL
measurements). For example, an RSL of -60dBm yields an RSL voltage
measurement of 0.60VDC; an RSL of -45dBm measures 0.45VDC.
• ExaltGUI RSL reading indicates the current RSL in dBm.
Alignment of the antennas using the RSL test point can be accomplished in the following
ways:
• Radio near or at antenna location
¶ Temporarily connect the radio to the antenna using a short piece of transmission
line, so that the radio is very close to the antenna location
– Run wires, as necessary, from the RSL test point to the volt meter so that the
antenna installer can directly view the volt meter
Note: Using this method, the final RSL voltage readings during
alignment may be different (better) than the planned RSL, due to the short
RF transmission line. Use the path calculation tool to determine the RSL
that should result in this temporary configuration to ensure proper ideal
alignment.
• Run separate wires from radio mounted location to antenna location
¶ Temporarily connect a set of wires from the RSL test point to the antenna
location, to allow the radio installer to use a local volt meter