Furuno CSH-5 MARK-2 - Manual (Page 21)

15
Adjusting the Gain
The gain should be adjusted to see fish echoes clearly with minimal
noise on the screen. Too high a setting not only causes excessive
noise on the screen and makes it difficult to discriminate wanted fish
echoes but also causes seabed echoes to be painted in strong colors,
resulting that the echoes from bottom fish are masked by seabed re-
flections. Normally, positions “3” thru “7” are used.
Gain Low Gain Proper Gain High