USER’S MANUAL
SERIES 48710 RF REPEATER
THEORY OF OPERATION
The 48710 series signal boosters are designed to enhance radio communications in buildings, basements,
tunnels and other RF shielded environments. The 48710 is tuned for the 800 MHz SMR band and the
48722 is tuned for the 900 MHz SMR band.
These units work by receiving and amplifying the Base TX signals via a donor antenna directed at the
desired base site. This RF path is called the ‘downlink”. The amplified base TX signal is re-radiated via
antenna(s) or radiating cable into the “Service Area”. Subscriber mobile RF signals are received by the
same service area radiating elements, amplified in the “uplink”RF path to be radiated back to the base via
the donor antenna.
The LNAs and Power Amplifiers are broadband. The same models are used for the uplink and
downlink on both the 48710 and 48722. Likewise, the control board is the same for both models.
Differentation is provided by the duplexing filters on the base and service area connectors that determine
the basic pass band and direct the RF signals to the proper gain path, uplink and downlink respectively.
Both links have automatic gain control (AGC) in the power amplifiers to prevent overdrive. Manual
gain adjustment is provided in the LNA stage. Overdrive limiting is provided by the AGC circuitry and
set at the factory and so that the 48710 series will not exceed the FCC limits for spurious emissions
The control board distributes DC power to the amplifier modules and monitors each module for any
fault condition. LED indicators provide visual diagnostics while the 15 pin din connector has DC and
TTL test points for more in depth trouble shooting.
Block Diagram
Duplexers
48710 5595
48722 J09020
Service
Base
PA80-9942
LNA80-0002
PA80-9942
LNA80-0002
Uplink
48710 806-824 MHz
48722 896-902 MHz
Downlink
48710 851-869 MHz
48722 935-941 MHz
Control Board
ELECTRICAL SPECIFICATIONS
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3 48710-22Manual.doc
