Furuno color video plotter GD1720C - Manual (Page 139)

4. VIDEO SOUNDER OPERATION
4-10
1. Press the MENU key.
2. Press the SOUNDER MENU soft key.
3. Select NOISE LIMITER, then press the EDIT soft key to show the noise limiter window.
NOISE LIMITER
▲
¤ OFF
¡ LOW
¡ MEDIUM
¡ HIGH
▼
Noise limiter window
4. Use the Cursor pad to select the degree of suppression desired (LOW, MEDIUM,
HIGH), or turn the noise limiter off.
5. Press the RETURN soft key followed by the MENU key to close the menu.
Turn the noise limiter circuit off when no interference exists, otherwise weak echoes may be
missed.
4.6 Reducing Low Level Noise
Light-blue dots may appear over most of the screen. This is mainly due to sediment in the
water, or noise. This noise can be suppressed by adjusting CLUTTER on the SOUNDER
menu.
Appearance of clutter
When the automatic sounder mode is used, clutter is automatically adjusted. To reduce low
level noise in manual sounder operation do the following:
1. Press the MENU key.
2. Press the SOUNDER MENU soft key.
3. Select CLUTTER, then press the EDIT soft key to show the clutter window.
CLUTTER
▲
09
▼
Clutter window
4. Adjust the Cursor pad upward or downward to select clutter rejection level desired; 0