Furuno NAVNET 1833 - Manual (Page 51)

2. RADAR OPERATION
2-17
2.13 Reducing Noise Interference
Noise, appearing on the displays as random “speckles,” can be reduced as
follows:
1. Press the [MENU] key to open the menu.
2. Press the RADAR DISPLAY SETUP soft key.
3. Select NOISE REJECTION, then press the EDIT soft key.
4. Select OFF, LOW or HIGH as appropriate.
5. Press the ENTER soft key.
6. Press the [MENU] key to close the menu.