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8 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E

The test can be performed by installing a radio at each end of the pro-

posed link and checking the RSSI value reported at the radio’s front

panel display. (See “Front Panel Indicators” on Page 25.) If adequate

signal strength cannot be obtained, it may be necessary to mount the sta-

tion antennas higher, use higher gain antennas, or select a different site

for one or both stations.

To prepare the equipment for an on-the-air test, follow the general

installation and operation procedures given in this guide and become

familiar with the operating instructions given in Section 5.0,

START-UP

AND OPERATION

, beginning on Page 24.

A Word About Interference

Interference is possible in any radio system. However, since the

MDS 4790/9790 Series is designed for use in a licensed system, inter-

ference is less likely because geographic location and existing operating

frequencies are taken into account when allocating frequencies.

The risk of interference can be further reduced through prudent system

design and configuration. Allow adequate separation between frequen-

cies and radio systems.

Keep the following points in mind when setting up your radio system:

1. Systems installed in lightly populated areas are least likely to

encounter interference; those in urban and suburban environments

are more likely to be affected by other devices operating on nearby

frequencies.

2. Directional antennas should be used at the remote end of the link.

They conﬁne the transmission and reception pattern to a compara-

tively narrow beam, which minimizes interference to and from sta-

tions located outside the pattern.

3. If interference is suspected from another system, it may be helpful

to use antenna polarization that is opposite to the interfering sys-

tem’s antennas. An additional 20 dB (or more) of attenuation to

interference can be achieved by using opposite antenna polarization.

3.2 Antenna and Feedline Selection

Antenna System

The antenna system is perhaps the most crucial part of the system

design. An antenna system that uses poor quality feedline, or is improp-

erly aligned with the companion site, will result in poor performance, or

no communication at all.

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MDS MDS 4710 Series Specifiche Pagina 16