What capabilities does HF offer?

• A. 2-29 MHz; Long range, over-the-horizon; ground and sky propagation; up to 2.5 kbps
• B. 30-88 MHz; 16 kbps
• C. 2-29 MHz; 16 kbps
• D. 225-400 MHz; LoS

Answer: (A)

HF operates in the 2 to 29 MHz range, using both ground-wave and ionospheric sky-wave paths to reach long distances well beyond the line of sight. This ionospheric reflection, plus ground-wave propagation, enables over-the-horizon links that are a hallmark of HF. The data rates typical for HF are modest, with up to about 2.5 kbps achievable under favorable conditions. The other options point to higher bands (VHF or UHF), which rely on line-of-sight propagation and don’t offer the same long-range reach, and they also imply data rates that aren’t characteristic of standard HF capabilities.