Multiplier Improves the Dynamic Range of Echo Systems Multiplier Improves the Dynamic Range of Echo Systems (HA-2556, HA-5177) Application Note November 1996 AN9515.1 Introduction In an echo system the returned signal amplitude is a function the time it takes sound to travel approximately one foot of the distance to the target, and it can be expressed mathe- through air. During the rst portion of the ramp, when the matically as function of time. An echo system with a xed returned signal is very large, the multiplier gain is small gain preamp has poor dynamic range because close targets because……