Erasing Weak Echoes - Furuno 1722C Operator's Manual

4. VIDEO SOUNDER OPERATION
4.8

Erasing Weak Echoes

Sediment in the water or reflections from plankton may be painted on the display
in green or light blue (color display) or "spots" on the background (monochrome
display). These weak echoes may be erased as below.
1. Press the [MENU] key.
2. Press the SOUNDER MENU soft key.
3. Select SIGNAL LEVEL, and press the EDIT soft key to show the signal level
window.
4. Use the cursor pad to select level of erasure or OFF as appropriate. The
higher the number the stronger the echo that will be erased.
5. Press the RETURN soft key followed by the [MENU] key to close the menu.
Note: Unlike "clutter," signal level erases echoes. Therefore if you do not wish to
erase echoes use clutter instead.
4-14
Appearance of weak echoes
SIGNAL LEVEL
¤
OFF
¡
SL1
SIGNAL LEVEL
¡
SL2
¡
¤
SL3
¡
¡
SL4
¡
¡
SL5
¡
¡
SL6
16-color display
Signal level window
Weak
echoes
SIGNAL LEVEL
OFF
¤
OFF
SL1
¡
SL1
SL2
¡
SL3 SL2
8-color display Monochrome display