Motorola Solutions Inc. 99FT5029 사용자 설명서

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페이지 40
6816814H01
December 2009
Electrical Connections RF Antenna Connections
4-3
4.2
RF Antenna Connections
The transmit and receive antenna RF connection are made using two separate connectors. Coaxial 
cables from the receive and transmit antenna must be connected to the Type-N (Tx) and BNC (Rx) 
connectors. The position of these connectors is shown in 
. For repeater use, the antennas 
need adequate isolation between them, or if one antenna is used, the duplexer needs to have 
adequate isolation between the Tx and Rx ports. The isolation requirements are unique to each band 
and are shown in the table below:
 
If the duplexer isolation is not adequate, a preselector may also be used. 
 for a list of available duplexers and preselectors.
4.2.1
Duplexer Selection
The selection of a duplexer is critical to system performance. The use of a notch (band reject) 
duplexer is possible in some systems that are not located at high RF density sites. 
 
for a list of available duplexers. The duplexer must be able to handle at 
least 50 W continuously. For the best system performance, the insertion loss should be less than 2 
dB. If the repeater is used in higher RF density sites, the use of a pass-notch duplexer is 
recommended.
Frequency Band
Bandwidth
Isolation
UHF 1
403–470 MHz
75 dB
UHF 2
450–512 MHz
85 dB
VHF
136–174 MHz
85 dB
800
806–870 MHz
80 dB 
The repeater can key up at any time due to input from a subscriber unit or a 
CW ID. Please ensure that all power is switched off before disconnecting the 
transmit antenna.
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C a u t i o n