Furuno FR-10, Operator'S Manual

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2. OPERATION
2-19
2.17 Interference Rejector
Radar interference can occur when your ship is near the radar of another ship that op-
erates on the same frequency band with your radar. The interference shows on the
screen as many bright dots. The dots can be random or in the shape of dotted lines
that run from the center to the edge of the display. You can identify the interference
from the normal echoes, because the interference does not appear in the same loca-
tion at the next antenna rotation. When this feature is turned on, "IR" appears at the
lower-right corner.
1. Press the MENU key to open the menu.
2. Press

or

to select [Echo], then press the ENTER key.
3. Press

or

to select [Int Rejector], then press the ENTER key.
4. Press

or

to select [Off] or [On] then press the ENTER key.
5. Press the MENU key to close the menu.
Note: When there is no interference, turn off the interference rejector so you do not
miss the small targets.
2.18 How to Measure the Range to a Target
You can measure the range to a target in three methods. the fixed range rings, the
cursor (if set to measure range and bearing), and the VRM (Variable Range Marker).
Use the fixed range rings to get a rough estimate of the range to a target. The fixed
range rings are the concentric solid circles about your ship. The number of rings
changes with the selected range scale. The interval of the range ring is displayed at
the upper-left corner of the screen. Count the number of rings between the center of
the display and the target. Check the range ring interval and measure the distance of
the echo from the nearest ring.
2.18.1 How to adjust range ring brilliance
1. Press the MENU key to open the menu.