ARRL Technician Practice Exam

What is a common application of a Yagi antenna?

1. Long-distance communication

2. Shortwave broadcasting

3. Amateur radio direction finding

4. Local FM transmission

The correct answer is: Amateur radio direction finding

A Yagi antenna is commonly used in amateur radio direction finding because of its directional characteristics and high gain. The design of a Yagi antenna features a series of elements, including a driven element, reflectors, and directors, which allows it to focus radio waves in a specific direction. This makes it particularly effective for locating the source of a radio signal by enabling the operator to determine the direction from which the strongest signal is received. While the other applications listed may be relevant to different types of antennas, they do not leverage the Yagi's specific advantages in the same way. For instance, long-distance communication is typically achieved with various antenna designs that provide global coverage rather than the specialized directionality of the Yagi. Shortwave broadcasting and local FM transmission generally employ antennas that serve different purposes, such as broad coverage or vertical polarization, which are not the primary strengths of a Yagi antenna.