A powerful portable audio system for listening collectively to recorded or broadcast sound.
Any frequency in this range, especially when used in broadcasting.
Many stations broadcast on shortwaves.
An electromagnetic wave having a wavelength between approximately 10 and 100 meters, corresponding to frequencies between 3 and 30 MHz.
Downward radiation entering the earth's atmosphere that is in the shortwave frequency range.
Having a wavelength of approximately 10 to 100 meters.
Capable of transmitting or receiving signals at such a wavelength.