Amplitude Modulation (AM) (AM)

A modulation method in which the amplitude of a radio-frequency carrier varies in accordance with the information signal.

Conventional AM transmits a carrier and two sidebands, while single-sideband marine HF and MF voice suppresses the carrier and one sideband for greater power and bandwidth efficiency.

AM is susceptible to amplitude noise and fading. Marine radio users must select the specified emission mode and channel; AM, SSB and FM are not interchangeable simply because they carry speech.