Ham Amateur Radio Technician Practice Exam 2026 - Free Technician Practice Questions and Study Guide

The purpose of an antenna tuner is primarily to increase power transfer from the transmitter to the feed line by matching the impedance of the transmitter to that of the antenna system. In radio communications, different antennas have various impedance characteristics, and when the impedance of the transmitter does not match that of the antenna, some of the signal can be reflected back to the transmitter instead of being transmitted.

An antenna tuner adjusts the impedance to ensure that maximum power is delivered to the antenna, thereby improving the efficiency of the overall system. This matching is crucial for effective radiation of the RF signal and can lead to better communication range and clarity.

While some other functionalities, such as reducing signal loss and protecting the transmitter, might be related or secondary effects of using an antenna tuner, the primary function remains focused on impedance matching to enable optimal power transfer.