Furuno NAVIONICS GP-1650WDF Operator's Manual page 20

2. VIDEO SOUNDER OPERATION
Selecting display range
Press the RANGE soft key to show the
range window, and select range by the
cursor. Press the RETURN soft key to finish.
RANGE
1000 ft
2500 ft
Range window
Adjusting the gain
Press the GAIN soft key to show the gain
window, and press ▲ or ▼ to set the gain.
Current level is shown above the bar. Press
the RETURN soft key to finish.
GAIN
HIGH
LOW
Gain window
Note: On the dual-frequency display, the
gain can be independently set for 50
kHz and 200 kHz. This can be done
with the GAIN 50 kHz and GAIN 200
kHz soft keys.
Normally, set the gain to the point where
excessive noise does not appear on screen.
Use a higher gain setting for greater depths
and a lower setting for shallow waters.
2-6
15 ft
30 ft
60 ft
120 ft
200 ft
400 ft
57
Gain too high Gain proper
Examples of proper and improper gain
Range shifting
The basic range may be shifted up or down
as desired.
Press the SHIFT soft key, and press ▲ or ▼
to shift the basic range. Press the RETURN
soft key to finish.
Shift
Shift concept
Gain too low
Display