High frequency (HF) is an electromagnetic frequency defined by the International Telecommunications Union (ITU) for radar and radio communications . It operates in a range of three to thirty MHz and as the wavelengths spread over ten to one hundred meters, it is also known as decameter wave and designated as band 7.
Read moreWhy do we use high frequency carrier for modulation?
For the transmission of audio signals at distant places, the high frequency carrier waves are used, because these frequency carrier waves travel through space or medium with the speed of light and they are not obstructed by earth’s atmosphere .
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