Furuno FAR-21 7-BB Series, Operator'S Manual

Page: 97 / 305

1. RADAR OPERATION
1-71
1.37 Suppressing Second-trace Echoes
In certain situations, echoes from very distance targets may appear as false
echoes (second-trace echoes) on the screen. This occurs when the return echo
is received one transmission cycle later, or after a next radar pulse has been
transmitted.
Second-trace
echo
Tx repetition
Actual range
False echo
range
Second-trace echoes
To reject second-trace echoes:
1. Roll the trackball to choose the MENU box at the right side of the screen and
then push the left button.
2. Roll the wheel to choose 1 ECHO and then push the wheel or the left button
to open the ECHO menu.
[ECHO]
1 BACK
2 2
ND
ECHO REJ
OFF/ON
3 TUNE INITIALIZE
4 PM*
1
OFF/ON
5 SART
OFF/ON
6 WIPER
OFF/1/2
7 ECHO AREA*
2
CIRCLE/WIDE/ALL
*
1
Not available on FAR-2157/2167DS
*
2
Not available on IMO or A type
ECHO menu
3. Roll the wheel to choose 2 2
ND
ECHO REJ and then push the wheel or the
left button.
4. Roll the wheel to choose OFF or ON as appropriate and then push the wheel
or the left button.
5. Push the right button twice to close the menu.