What Is A Repeater:
A repeater is a two-way radio system that receives on one frequency and then re-transmits what it hears on another frequency at exactly the same time. It’s nothing more than a “dumb relay machine” with some really smart people behind it.
Why it’s needed:
Your handheld radio has limited range due to it’s antenna height with respect to the radio horizon. Repeater systems are placed on high points with large antennas and are used to “transfer” or “repeat” your transmitted and received signals to much higher elevations.
How Does It Work:
A repeater consists of a transmitter, receiver, duplexer and antenna. What is heard on the input frequency is simultaneously transmitted on the output frequency. The duplexer allows one antenna to operate in transmit and receive at the same time.