Shortwave

[Zipporah Schumaker]

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

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.

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.

[Mark Zuckerberg]

A radio wave of a wavelength between about 10 and 100 m (and a frequency of about 3 to 30 MHz)

[Justin Bieber]

A fascinating but, unfortunately it seems, [moribund] form of radio broadcasting that utilizes radio frequencies from about 1,800 kHz to 30,000 kHz. Some say that the Internet is totally to blame for [shortwaves] demise, but in fact there are many other reasons: poor propagation conditions (e.g. coronal flares on the Sun that can block radio reception for many days), mismanagement and bad frequency [allocation] by the stations themselves, transmitters in [disrepair], lack of funding for the stations, radio frequency interference caused by various appliances that create walls of noise when one is listening for stations, etc. On shortwave, one can often hear interesting cultural programs and music produced by the host country, and some shortwave listeners have created a hobby-within-a-hobby of collecting [QSL] (verification of reception) cards, pennants, CDs, books, etc.