1. Radio waves are signals 2 system is amplitude modulation (A.M. = amplitude modulation) and FM system (F.M. = frequency modulation). For use in the radio communication, the information communication.2. Used in communication, such as the case of communication between police officers. Between the agencies of government and amateur radio system.3. Be used in telecommunication field, such as the use of marine communication international communication, short wave radio4. Send television and radar, microwave transmission.
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