User's Manual

Table Of Contents
Printed Documentation
60
Antenna Configurations
AS4000
This section describes the various antenna configurations and modifications needed to the
baseband wiring if the AS4000 CT rack is configured so that the two modem shelves serve
separate directional antenna. and the subsequent connection arrangements when an
expansion rack is fitted.
1. Standard configuration for Antenna (omni or sectored) using 2 RFs on one Antenna
initially and 2 RFs per antenna when an Expansion Rack and second Antenna are
added
Figure 1 Combiner Shelf Ribbon Connections Before Modification
2. Rack Modification for two separate directional Antenna using 1RF per Antenna
initially and 2 RFs per sector when an Expansion Rack is added
The modification consists of re arranging the baseband cables from the modem shelves such
that the bottom shelf in the CT rack now connects to RF Card 3 and consequently will feed
into the antenna connected to DIP/LNA 2. If an expansion Rack is fitted then the top shelf
connects to RF Card 2 and will feed into the antenna connected to DIP/LNA 2. A block
diagram of the system after modification is shown below.
Modification to CT Rack