User's Manual

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 Figure 4-1. 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. See “Accessories” on
page 6-1 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. See
“Accessories” on page 6-1 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