1) when referring to (
radio) broadcasting, includes frequencies ranging from 1.7 to
30 MHz (1700 -
30,000 kHz), but sometimes refers also to the HF frequency spectrum from 3 to
30 MHz
2) An adjective referring technically to radio waves shorter than
80 meters, corresponding to a frequency of 3.75 megahertz or more. The term is often loosely used to refer to HF frequencies.
3) In radio communications, pertaining to the band of frequencies approximately between 3 MHz and
30 MHz. Note: “Shortwave” is not a term officially recognized by the international community.