Furuno GP-3500F - Manual (Page 196)

11. VIDEO SOUNDER OPERATION
11-24
10. Press the [ENTER] knob.
The color changed at steps 8 and 9 is entered to the color bar.
11. Repeat steps 6 through 10 to change other color.
12. Press the [MENU] key several times to close the menu.
Note: To restore the colors to the default setting:
a) Open the USER COLOR SETUP menu.
b) Rotate the [ENTER] knob to select USER COLOR.
c) Select the number for the color to restore.
d) Rotate the [ENTER] knob to select DEFAULT SET.
e) Press the [1] key to select “1. YES.”
f) Press the [MENU] key several times to close the menu.
11.12 Erasing Weak Echoes
Sediment in the water or reflections from plankton may be painted on the display
in green or light blue. These weak echoes may be erased as below.
Weak echoes
Appearance of weak echoes
1. Press the [MENU] key to show the main menu.
2. Press the [9] key to show the ECHO SOUNDER SETUP menu.
3. Press the [7] key to how the SIGNAL LEVEL window.
SIGNAL LEVEL
1. OFF
2. SL1
3. SL2
4. SL3
5. SL4
6. SL5
7. SL6
SIGNAL LEVEL
16 colors 8 colors
1. OFF
2. SL1
3. SL2
4. SL3
Signal level window
4. Rotate the [ENTER] knob to select level of erasure or OFF appropriate. The
higher the number the stronger the echo that will be erased.
5. Press the [ENTER] knob.
6. Press the [MENU] key several times to close the menu.