Exalt Installation and Management Guide
ExtendAir (TDD) Series Digital Microwave Radios
30
203591-010
2012-09-04
transmission line is over-bent or kinked, it will likely never recover its specified characteristics, even
after straightening, and will often be completely unusable.
The opposite end of this primary transmission line typically terminates at the radio connector. If using
a long transmission line (in excess of 3'/1m), an RF lightning arrestor is recommended to protect the
radio equipment.
As soon as practical, weatherproof the connected ends of the transmission line to the antenna and
lightning arrestor and radio. This process should be delayed as long as possible to ensure that all
systems are working properly before applying the weatherproofing. Once weatherproofing is applied,
it may have to be removed for testing or installation modification. With this in mind, if the installation
is occurring during inclement weather, take extra care at all times to ensure that no moisture enters any
connector at any time. If moisture is suspected to have compromised the antenna or transmission line,
it may render those devices useless without any means for remedy except for full replacement.
Cap and weatherproof the second antenna connector on the radio if using a single-polarity antenna.
Indoor Mounting
On rare occasions the antenna can be mounted indoors behind a window. In these cases, there would
not be a need for drip loops or an RF lightning arrestor. Use a very short transmission line connected
directly between the antenna and the radio mounted nearby. The weatherproofing process can also be
omitted.
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
•
Citel PRC5800
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 ExtendAir (TDD) Series radios have 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
