User's Manual

Exalt Communications, Inc.
Exalt i-Series Installation and Management Guide
5000001 63
2007-04-15
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 building
or enclosure, where it might harm 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 egress point where the next piece of
transmission line enters the building or enclosure. Minimize the distance to the egress to
lessen the opportunity for lightning to couple to or strike the unprotected section of
transmission line (if any). Where possible, use a bulkhead connector to eliminate any
opportunity of this risk. Keep cable lengths behind the arrestor and into the egress
substantially short (less than 3'/1m) as a safe practice. Consult a qualified electrician or
installer in all cases of grounding and lightning arrestor implementation.
Transmission Line from Egress to Radio
A single transmission line section from the egress to the radio RF connection is always
desired. Minimize the number of connectors and adapters. For indoor runs, a cable ladder
or tray may be needed to properly secure the cable. In some cases, a short flexible jumper
allows ease of connection to the radio’s RF connector. A properly specified 90º connector
can often eliminate this need. An installation with space around the radio to
accommodate a gentle bend radius of the transmission line is also good for a direct
connection. In all cases, ensure that the transmission line is not a pulling force of the RF
connector on the radio. Transmission lines can be very stiff and can damage the
connector if not dressed properly. Also, follow the transmission line manufacturer’s
instructions for the proper use of cable securing devices.