short wave
From Longman Dictionary of Contemporary EnglishRelated topics: Broadcastingshort waveˈshort wave noun [uncountable] TCBa range of short radio waves used for broadcasting around the world → long wave, medium waveExamples from the Corpusshort wave• It says that, in affected areas, only a minority listens on short wave.• Broadcasting was on short wave only and at such low power that the reception area was limited, scattered and unpredictable.