Measuring Depth - Furuno GP-1640F Operator's Manual

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 50kHz and GAIN 200kHz 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.
Gain too high Gain proper
Examples of proper and improper gain
2-6
57
Gain too low
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
2.7

Measuring Depth

The VRM functions to measure the depth to
fish schools, etc., and it is always displayed.
1. Press ▲ or ▼ to shift the VRM.
2. Depth is shown just above the VRM.
VRM
30
20
10
0
54.0
GPS 3D
50k
How to use the VRM
Display
Depth to VRM
SOUNDER
RANGE
15.0
20
GAIN
30
SHIFT
40
MODE/
FREQ
50
SNDR
FUNC