Furuno NAVIONICS GP-1850F - Manual (Page 21)

2-7
2.8 Suppressing Interference
Interference from other acoustic equipment
operating nearby or other electronic equip-
ment on your boat may show itself on the
display as shown in Figure 2-20.
To suppress interference, do the following:
1. Press the [MENU] key and the soft key
SOUNDER SETUP OPTIONS.
2. Select NOISE LIMITER and press the soft
key EDIT to show the noise limiter win-
dow.
NOISE LIMITER
▲
' OFF
™ NL1
™ NL2
™ NL3
▼
Figure 2-20 Noise limiter window
3. Press ▲ or ▼ to select degree of sup-
pression desired; OFF, NL1, NL2 or NL3.
The higher number the greater the degree
of suppression.
4. Press the soft key RETURN and the
[SNDR] key to finish.
Interference from Electrical inteference
other sounder
Figure 2-21 Types of interference
Turn the noise limiter circuit off when no in-
terference 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 ad-
justing CLUTTER on the SOUNDER SETUP
OPTIONS menu.
When the sounder mode is Auto, the clutter
suppression setting is fixed at AUTO. To sup-
press low level noise in manual sounder op-
eration do the following:
1. Press the [MENU] key and the soft key
SOUNDER SETUP OPTIONS.
2. Select CLUTTER and press the soft key
EDIT to show the clutter window.
CLUTTER
▲
3
▼
Figure 2-22 Clutter window
3. Press ▲ or ▼ to select clutter rejection
level desired; 0 (OFF) through 9. The
higher the number the higher the degree
of suppression. Note that weak echoes
may not be displayed when the clutter cir-
cuit is on.
4. Press the soft key RETURN and the
[SNDR] key to finish.
Figure 2-23 Appearance of clutter