Gain controls the sensitivity of the Radar receiver. Auto (default) is the recommended setting. It automatically adjusts the gain for each range scale to provide optimal performance. You can also set gain manually. To see more detail, increase the receiver sensitivity by selecting a higher gain. If there is too much detail, or the screen is cluttered, lower the sensitivity (lower the gain) to increase the clarity of the screen.
Sea ClutterSea Clutter controls unwanted screen clutter caused by choppy sea conditions. The slider has three preset positions: Calm, Moderate, and Rough.
Rain ClutterRain Clutter controls unwanted screen clutter caused by rain at close ranges (use the slider to select
FTC controls unwanted screen clutter caused by rain at a distance. The Fast Time Constant settings are: Off, Low, Medium, and High.
ZoomZoom allows you to zoom in on a selected area of the radar screen. When you select a zoom range, a window showing a zoomed portion of the screen appears in the
Basic Operation > Radar Page
appears. To view different areas at the selected zoom range, open the Radar adjustment menu, highlight Zoom, and press the Move soft key. Use the ROCKER to move the selection box. Zoom has four settings: Off, 2x, 4x, and Move.
Zoom view | Selection box |
Use Target Expansion to increase the size of targets. Select On or Off.
NOTE: The Target Expansion setting has no effect at range scales of 4 nm or greater.
GMR 21/41 Owner’s Manual |