Telenetics OM-AMPS-100 manual General Guidelines, High Voltage Areas, RF Signal, Gain

Section 5

External Antenna Guidelines

Introduction

5 This section provides guidelines about using an external antenna with OMEGA. If you will not be using an external antenna, you can skip this section

General Guidelines

The following guidelines provide general topics about using an external antenna with your OMEGA.

High Voltage Areas

To avoid any damage, serious injury, or possible death, never install an antenna near high-voltage power lines. Telenetics recommends that you provide lightning protection for all external antennas.

RF Signal

Antennas cannot amplify an radio-frequency signal. Rather, they are designed to concentrate the radiated signal in a specific pattern or focus it in a particular direction. The range of an antenna can be increased by concentrating or focussing the signal.

Gain

An antenna’s gain is one of its identifying characteristics. Terms such as unity gain, 3dB gain, and 9dB gain are common. The amount of gain of an antenna is based on that of a true omni- directional antenna. This type of antenna radiates the transmitted signal in all directions. If the radiated power were visible, it would resemble a sphere encompassing the antenna.

An omni-directional antenna is described as having unity gain. A 3dB gain antenna has a greater range. This type of antenna is also referred to as omni-directional because the signal is transmitted in all directions. However, the signal is concentrated in a horizontal plane, so instead of a spherical “image”, its radiated power image resembles a disk. With this type of RF signal concentration, a 3- watt 3dB gain antenna has the equivalent range of a 6-watt unity gain antenna and is said to have 6 watts of Effective Radiated Power (E.R.P.).

OMEGA Installation, Operation, and Maintenance Manual 47