Furuno CI-68 Operator's Manual page 38

3. CUSTOMIZING THE SYSTEM
ECHO RANGE
Choose the maximum depth to display echoes, from among 50, 100, 150, 200, 250, 300,
350, 400, 450, 500 (m).
TVG
Turn echo TVG on or off.
GAIN
Adjust echo level display color. The higher the digit the nearer to the strongest color
(reddish brown). "GAIN" does not adjust the gain of the received signal; speed and tide
values are not affected by this adjustment. The setting range is 1-40.
PANEL DIMMER
Adjust the backlighting for the control panel, from 0-7.
3-6