User's Guide

1212
§ Install service area antenna(s).
Determining the location and type of service area antennas is part of the distribution system
design. Generally, it is desired to minimize the amount of coax that has to be installed. However,
in buildings with extensive obstructions, it may be necessary to install several service area
antennas. For assistance with antenna placement, contact RFS Applications Engineering.
§ Mount repeater upright, with the connections toward the floor.
Ensure there is sufficient space above and below the unit to allow airflow through the heat sink.
Check to make sure the AC power cord can reach the power source. Also, provide adequate
bending radii for the coaxial cables.
§ Connect service antenna(s) to "Service" via a 50-ohm coaxial cable.
Multiple service area antennas/radiating cable runs may be connected to the 48900. Splitters and
taps may be used to accommodate unique distribution systems. RFS has all the components
needed to complete even the largest installations. Visit our website at: www.rfsworld.com, or call
us.
§ Connect the donor antenna cable to "Base".
§ Connect AC power to the unit and observe power and fault LEDs
§ Adjust manual gain .
If the yellow DL AGC LED is lit then it is suggested that you reduce the gain in the DL via the
manual attenuator. Turn the adjustment clockwise to reduce gain until the AGC LED goes out.
Then adjust the UL gain to the same setting to minimize noise generated in the uplink.
If both LEDs are lit then there is likely a oscillation between the antennas – see “Antenna
Isolation”. Also read the section on “Intermodulation, Power, and AGC”
§ Test the installation.
This test should include multiple subscribers in various locations of the service area. It should
also include one subscriber in fairly close proximity to the repeater. This test will check to ensure
that a nearby user does not overdrive the uplink and reduce coverage for the other users.
If the UL AGC LED lits during the system test it most likely indicates that there is a hot spot in the
service area where the subscriber signal is overdriving the uplink. It is best to minimize this effect
by relocating the nearest service antenna or adding a attenuator pad to reduce the UL signal
strength.
IMPORTANT
Observe Maximum Permissible Exposure cautions when determining the type and
location of all antennas.