2-8

2.10 Erasing Weak Echoes
Dirty water or reflections from plankton may
be painted on the display in green or light
blue. These weak echoes may be erased as
follows:
1. Press the [MENU] key and the soft key
SOUNDER SETUP OPTIONS.
2. Select SIGNAL LEVEL, and press the soft
key EDIT to show the signal level window.
SIG LVL
'OFF
SL1
SL2
SL3
SL4
SL5
SL6
SIG LVL
'OFF
SL1
SL2
SL3
At 16-color display At 8-color display
(See page 2-9.)
Figure 2-24 Signal level window
3. Press or to select level of erasure;
OFF or signal level among SL1 to SL6
(or SL3). The higher the number the stron-
ger the echo will be erased.
4. Press the soft key RETURN and the
[SNDR] key to finish.
Weak
echoes
Figure 2-25 Appearance of weak echoes
2.11 White Marker
The white marker functions to display a par-
ticular echo color in white. For example, you
may want to display the bottom echo (red-
dish-brown) in white to discriminate fish ech-
oes near the bottom. Note that the bottom
must be displayed in reddish-brown for the
white marker to function.
1. Press the [MENU] key and the soft key
SOUNDER SETUP OPTIONS.
2. Select WHITE MARKER, and press the
soft key EDIT to open the white marker
window.
WHITE MARKER
3
Figure 2-26 White marker window
3. Press or to select color to display in
white. As you press or , the number
(corresponds to echo number) in the
marker window changes, the white
marker on the color bar shifts and selected
echo color is displayed in white. When you
select 8 in HUE window (See page 2-9.),
white marker is among 0 to 8.
White marker shows
color currently
displayed in white.
Figure 2-27 Color bar when white
marker function is active
4. Press the soft key RETURN and the
[SNDR] key to finish.
To turn the white marker function off, display
“0” in the white marker window.