Consumer Electronics
Math and Arithmetic
Electronics Engineering

Why values of modulation index greater than one are not used in full-carrier AM system?



User Avatar
Wiki User

If the modulation index is greater than 1 (more than 100% modulation) the modulated carrier signal is periodically reduced to zero. This does not effect the transmitter but at the receiver these "dead carrier" intervals result in dropouts in the audio stream from the loudspeaker producing a distorted output that is difficult to understand.