Motorola DIMETRA MTS 2, Инструкция по установке, настройке и базовому обслуживанию

Страница: 42 / 517

MTS Modules Chapter 1: MTS Overview
MTS Modules
■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■
■
■
Each MTS is comprised of a number of modules. Some of these modules in turn are comprised of
subcomponents. This section provides an overview of each of the available modules and their subcomponents.
RF Distribution System
The RF Distribution System (RFDS) module has the following subcomponents:
•
Preselector (MTS2 and MTS4 prime only)
•
Duplexer (MTS2 and MTS4 prime only)
•
Post Filter (MTS4 prime only)
•
Cavity Combiners (CC) (MTS 4 and Expansion Cabinet only)
•
Hybrid Combiner (HC) (MTS 2 and MTS 4 Prime Cabinet only)
•
Rx Splitter (Expansion Cabinet Only)
MTS 2 and MTS 4 use different types of Preselector and Duplexer.
Preselector
The Preselector is a bandpass
fi
lter, which allows only the receiver signals to pass. For UHF, the
fi
lter’s
bandwidth is 5 MHz, and it is designed to block transmitter frequencies as close as 5 MHz from its band edges.
For 800 MHz, the
fi
lter’s bandwidth is 19 MHz. The Preselector incorporates a Receiver Multicoupler (RMC).
Duplexer
The Duplexer consists of two bandpass
fi
lters. One allows the transmitter signal to pass while the
other allows the receiver signal to pass. Both
fi
lters have a bandwidth of 5 MHz.
For UHF, the duplex spacing between a transmitter frequency and the corresponding receive frequency is
10 MHz, with the transmitter frequency being higher. This leaves a 5 MHz spacing between the lowest
possible transmit frequency and the highest possible receive frequency. For 800 MHz, the duplex spacing
between a transmitter frequency and the corresponding receive frequency is 45 MHz.
The Duplexer incorporates both an RMC and a Digital Power Meter (DPM).
1-8
6802800U74-N September 2009