Ubiquiti airFiber AF-5XHD Quick Start Manuals page 18

Mount the External GPS Antenna
Locate a mounting point that has a clear view to the sky, and is
above and as far away as possible from the AF-5XHD.
1. Attach the GPS Antenna Mount to the pole using the metal
strap, or attach it to a wall using the appropriate fasteners
(not included).
2. Place the External GPS Antenna on the mount.
3. Secure the cable of the External GPS Antenna to the mount
with a Cable Tie.