Which frequency band is commonly used for long-distance communication in amateur radio?

The frequency band that is most commonly used for long-distance communication in amateur radio is the HF band. HF, or High Frequency, covers a range of frequencies from 3 MHz to 30 MHz and has the unique ability to reflect off the ionosphere, allowing for skywave propagation. This characteristic enables signals to travel beyond the horizon and facilitates communication over vast distances, often across continents.

In contrast, UHF (Ultra High Frequency) operates between 300 MHz and 3 GHz and is typically used for local or short-range communications, including mobile radios and repeaters. VHF (Very High Frequency), which ranges from 30 MHz to 300 MHz, is also mostly suited for local communications, such as FM radio, television broadcasts, and amateur operations that do not require long distances. SHF (Super High Frequency) spans from 3 GHz to 30 GHz and is primarily used for satellite communications and microwave links, which are not ideal for amateur radio long-distance communication.

The ability of the HF band to utilize the ionosphere for long-distance signals makes it the go-to choice for amateur radio operators looking to connect with others around the world. This band is pivotal in emergency communications, international contests, and general on-air activity among amateur radio enthusiasts