Exalt Communications, Inc.
r-series
Installation and Management Manual
5000007 (ETSI)
32
2007-02-12 (draft)
RF Lightning Arrestor
RF lightning arrestors provide a direct path to ground for lightning strikes that may couple to or
directly hit the outdoor transmission system or antenna structure. The RF lightning arrestor
prevents any associated voltage and current from entering the radio equipment, other equipment,
or humans.
The following lightning arrestors are examples of proper devices for Exalt Digital Microwave
Radios:
•
Polyphaser AL-LSXM
•
Andrew BB-BNFNFE-26
Mount and ground the RF lightning arrestor in accordance to the manufacturer’s
recommendations. Place it as close as possible to the radio equipment. Minimize the distance to
the radio to lessen the opportunity for lightning to couple to or strike the unprotected section of
transmission line (if any). Consult a qualified electrician or installer in all cases of grounding and
lightning arrestor implementation.
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
. The r-Series has an integrated antenna.
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.
The following are the primary facilities when using the radio to align the antenna:
•
RSL voltage connection using a volt meter (recommended)
Insert the included adapter into the GPS connector on the radio housing and the opposite end
connected to a volt meter.
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.