What frequency range is referred to as HF?

The High Frequency (HF) band is designated by the ITU as the range from 3 MHz to 30 MHz. This band is famous in amateur radio for its ability to bounce off the ionosphere, allowing for long-distance, over-the-horizon global communication. It is easy to mix up the different band acronyms. Remember that 30 to 300 MHz is VHF (Very High Frequency), and 300 to 3000 MHz is UHF (Ultra High Frequency). The HF band sits just below VHF in the 3 to 30 MHz range.