Radar Interference; Erasing The Heading Marker - Furuno FR-7041R-MARK-2 Operator's Manual

1.15

Radar Interference

Radar interference may occur when near another marine radar operating in the
same frequency band as your radar. Its onscreen appearance is many bright dots
either scattered at random or in the form of dotted lines extending from the center
to the edge of the display. Figure 1-13 illustrates interference in the form of
curved spokes. Interference effects are distinguishable from normal echoes
because they do not appear in the same place on successive rotations of the
antenna.
To reduce radar interference;
1. Press the [MENU] key to display the menu.
2. Use the trackball to select INT REJECT.
3. Press the [ENTER] key to choose level of suppression desired. The inter-
ference rejection level indication, at the bottom right corner of the display,
changes cyclically in the sequence of OFF, IR1, IR2 and IR3. IR3 provides the
highest level of interference rejection.
4. Press the [MENU] key to close the menu.
1.16

Erasing the Heading Marker

The heading marker shows your vessel's heading. In the head-up and course-up
modes it appears at zero degrees; in the north-up and true motion modes it
changes direction according to ship's heading. When this marker obscures a
target echo, you can temporarily erase it by pressing and holding down the
[GAIN] control. Release the control to re-display the marker.
Figure 1-13 Radar interference
Heading marker
Figure 1-14 Heading marker
1. OPERATION
1-15