Codan Radio Radio Repeater Systems Training Guide - Manual (Page 25)

RADIO REPEATER SYSTEM | TRAINING GUIDE
Chapter 3: Repeater System Equipment Page 17
CHAPTER 3: REPEATER SYSTEM EQUIPMENT
When determining your system components remember that RELIABILITY is the most important
consideration. Quality equipment is worth the extra cost, particularly in the long term.
You must also remember that changing a component in one part of the system may affect the other
parts. For example, replacing the antenna type at one end of your linking path may require a change in
antenna at the other end, and a change in antenna mounting and / or housing may affect .... In other
words, there is great inter-dependence among the components. Remember also, when purchasing
equipment, to compare the range of temperature that is expected at the site(s) to the component
specifi cations supplied by the manufacturer.
In this section we are going to examine the individual pieces of equipment that make up the system.
REPEATER / BASE STATION
A repeater simply repeats everything that it hears. Any signal that is heard by the repeater’s receiver is
transmitted by the attached transmitter. A Base Station simply passes on received signals to a console
and the transmitter transmits audio from a console.
Repeaters can be assembled out of almost any combination of receivers and transmitters but in the
context of low power, high performance repeaters, some of the details take on a special signifi cance.
When a unit is powered by batteries, low current circuitry must be incorporated in the repeater to
conserve battery life. Also, when a repeater is located on a snow covered mountain top, or in desert-
like terrain, extreme temperature performance is important. A well designed grounding system is also
important since the radio equipment is exposed to lightning to a far greater extent when placed on
mountain tops. For greater coverage the repeaters can be connected in chains, so the cumulative audio
distortion must be low. Base stations are typically the center of a communications hub and need to
be of extremely high reliability for safety and continuity concerns, especially for law enforcement, fi re
departments and other public safety agencies.