Which radio has the longest range?

The range of a radio in amateur radio depends on various factors, such as the transmitter power, the type of antenna, the height of the antenna, the current propagation conditions and whether the bands are VHF/UHF or HF. In general, due to their ability to reflect from the ionosphere, shortwave (HF) radios have the potential to have the greatest range and can enable global communications. VHF/UHF radios typically have direct line-of-sight range, but can extend their range significantly through the use of relay stations or satellites.