<>Amplitude Modulation Communications (AM)

Three common methods (called "modulation") of voice communication are used. A.M.(Amplitude Modulation), S.S.B. (Single Side Band), and F.M. (Frequency Modulation). 

Amplitude Modulation (also know as Double Side Band). Not used much by Amateur Radio operators any more. Changes the STRENGTH of the radio signal according to how loud the voice is. Still used on the "AM" broadcast band (0.540MHz to 1.6MHz). Still used by most H.F. (Short Wave) International broadcasters such as the Voice Of America and the B.B.C. Requires twice as much "room" to transmit as S.S.B. so only half as many stations can fit in the legal bands allocated to Amateur Radio. Simple to receive.   Sound quality is quite good .