Garmin GPSMAP 4008 Owner's Manual page 80

Radar
Default Gain and Clutter Settings
Setting Default Value
Gain Auto
Sea Clutter Calm
Rain Clutter Off
FTC Off
Crosstalk On
Automatically Adjusting Gain on the Radar Screen
Auto is the default value for the gain setting. The automatic gain setting for each radar mode is optimized for
that mode, and may differ from the automatic gain setting used for another mode.
Note: Depending upon the radar in use, the gain setting configured for use in one radar mode may or may
not be applied to other radar modes or to the Radar Overlay
1. From the Home screen, select Radar.
2. Select Cruising, Harbor, offshore, Dual Range, or Sentry mode.
3. Complete an action:
• Select Menu > Gain > Auto for Cruising, Harbor, Offshore, or Sentry mode.
• Configure the setting for the short-range screen in Dual Range mode. Select
Auto for the GPSMAP 4000 series. Select Left > Gain > Auto for the GPSMAP 5000 series.
• Configure the setting for the long-range screen in Dual Range mode. Select
Auto for the GPSMAP 4000 series. Select Right > Gain > Auto for the GPSMAP 5000 series.
The chartplotter sets the gain automatically once based on average conditions, the range of the radar
signal, and the selected radar mode. The chartplotter does not readjust the gain automatically in response to
changing conditions.
Manually Adjusting Gain on the Radar Screen
For optimal radar performance that accounts for actual conditions, you can manually adjust the gain.
Note: Depending upon the radar in use, the gain setting configured for use in one radar mode may or may
not be applied to other radar modes or to the Radar Overlay
1. From the Home screen, select Radar.
2. Select Cruising, Harbor, offshore, Dual Range or Sentry mode.
3. Complete an action:
• Select Menu > Gain for Cruising, Harbor, Offshore, or Sentry mode.
• Configure the setting for the short-range screen in Dual Range mode. Select
the GPSMAP 4000 series. Select Left > Gain for the GPSMAP 5000 series.
• Configure the setting for the long-range screen in Dual Range mode. Select
the GPSMAP 4000 series. Select Right > Gain for the GPSMAP 5000 series.
4. Select Up to raise the gain, until light speckles appear across the Radar screen.
Data on the Radar screen is refreshed every few seconds. As a result, the effects of manually adjusting the
gain may not appear instantly. Adjust the gain slowly.
5. Select Down to lower the gain until the speckles disappear.
6. If boats, land, or other targets are within range, select Down to lower the gain until the targets begin to
blink.
7. Select Up to raise the gain until the boats, land, or other targets appear steadily lit on the Radar screen.
8. If necessary, minimize the appearance of nearby large objects
9. If necessary, minimize the appearance of side-lobe echoes
Minimizing Nearby Large-object Interference
Nearby targets of significant size, such as jetty walls, can cause a very bright image of the target to appear on
the Radar screen. This image can obscure smaller targets located near it.
Note: Depending upon the radar in use, the gain setting configured for use in one radar mode may or may
not be applied to other radar modes or to the Radar Overlay
76
Instructions
See "Automatically Adjusting Gain on the Radar Screen"
See "Restoring the Default Sea Clutter Setting"
See "Restoring the Default Rain Clutter Setting"
See "Restoring the Default FTC Setting"
See Adjusting Crosstalk Clutter on the Radar Screen"
(page
(page
(page
(page
(page
(page
(page
(page 78).
75).
> Menu > Gain >
> Menu > Gain >
75).
> Menu > Gain for
> Menu > Gain for
76).
77).
75).
GPSMAP 4000/5000 Series Owner's Manual
®
(page 76).
77).
78).
(page 80).