Furuno GP-1850WDF - Manual (Page 23)

2. VIDEO SOUNDER OPERATION
2-7
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. Read the depth just above the VRM.
SNDR
FUNC
SHIFT
GAIN
RANGE
SOUNDER
MODE/
FREQ
50k GPS 3D
VRM
20
30
40
50
30
20
10
0
42.0
17.5
Depth to VRM
How to use the VRM
Note:
This function is not available on the
plotter/sounder display.
2.8 Suppressing
Interference
Interference from other acoustic equipment
operating nearby or other electronic
equipment on your boat may show itself on
the display as shown in the illustration at the
top of the next column.
To suppress interference, do the following:
1. Press the [MENU] key and the
SOUNDER SETUP OPTIONS soft key.
2. Select NOISE LIMITER and press the
EDIT soft key to show the noise limiter
window.
NOISE LIMITER
▲
OFF
NL1
NL2
NL3
▼
Noise limiter window
3. Press ▲ or ▼ to select degree of
suppression desired; OFF, NL1, NL2 or
NL3. The higher the number the greater
the degree of suppression.
4. Press the RETURN soft key and the
[SNDR] key to finish.
Interference from Electrical inteference
other sounder
Types of interference
Turn the noise limiter circuit off when no
interference exists, otherwise weak echoes
may be missed.
2.9 Suppressing Low Level
Noise
Light-blue dots may appear over most of
screen. This is mainly due to dirty water or
noise. This noise can be suppressed by
adjusting CLUTTER on the SOUNDER
SETUP OPTIONS menu.
When the sounder mode is Auto, the clutter
suppression setting is fixed at AUTO. To
suppress low level noise in manual sounder
operation do the following:
1. Press the [MENU] key and the
SOUNDER SETUP OPTIONS soft key.
2. Select CLUTTER and press the EDIT soft
key to show the clutter window.
CLUTTER
▲
3
▼
Clutter window