Which band is known for its long-range communication capabilities due to skywave propagation?

The HF band, which ranges approximately from 3 to 30 MHz, is known for its long-range communication capabilities primarily due to skywave propagation. This phenomenon occurs when radio waves are transmitted into the atmosphere and are refracted or reflected by the ionosphere, allowing signals to travel over vast distances, often beyond the horizon.

HF frequencies are particularly well-suited for this type of propagation because they can effectively bounce off the ionospheric layers, especially during certain times of the day and under specific solar conditions. As a result, amateur radio operators frequently utilize HF for long-distance communications, often referred to as "DXing."

Other bands like VHF and UHF, while useful for communication, are primarily characterized by line-of-sight propagation, meaning they are limited to shorter distances without the aid of reflection from the ionosphere. The SHF band, in a similar vein, operates in frequencies that are even higher and are typically used for satellite communications and microwave links, which also rely on line-of-sight rather than skywave propagation.