ARRL Technician Practice Exam

What frequency range is referred to as HF?

1. 30 to 300 MHz

2. 300 to 3000 MHz

3. 3 to 30 MHz

4. 300 to 300 MHz

The correct answer is: 3 to 30 MHz

The frequency range referred to as HF, or High Frequency, is specifically from 3 to 30 MHz. This band is significant in amateur radio and telecommunications because it is primarily used for long-distance communications, owing to its ability to reflect off the Earth's ionosphere, especially during optimal conditions. HF bands are popular for various types of communication, including voice and digital modes, and they can support long-range contact even during times of low solar activity. The other ranges mentioned in the options refer to different classifications of frequencies. The range of 30 to 300 MHz is known as VHF (Very High Frequency), while the 300 to 3000 MHz range corresponds to UHF (Ultra High Frequency). The choice that states "300 to 300 MHz" appears to be an erroneous formulation and does not correspond to any established frequency band. Understanding these distinctions helps clarify how different frequencies function in radio communication.