Furuno FR-7112 - Manual (Page 26)

3-2
3.3 Suppressing Radar
Interference
Radar interference may occur when near another
shipborne radar operating in the same frequency
band as your radar. Its on-screen 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 3-4 il-
lustrates interference in the from of curved
spokes. Interference effects are distinguishable
form normal echoes because they do not ap-
pear in the same place on successive rotations
of the antenna.
Figure 3-4 Radar interference
Four levels of interference are available, includ-
ing off; IR1, IR2, IR3 and OFF. IR3 provides
the highest level of rejection.
1. Press the [MENU] key.
2. Select “INT REJECT” and press the [ACQ/
ENTER] key.
3. Select level desired by pressing the [ACQ/
ENTER] key.
4. Press the [MENU] key to close the menu.
IR and level selected appears at the bottom right
corner on the display when the interference re-
jection circuit is turned on.
3.4 Selecting Pulsewidth
Pulsewidth is the transmission time of a single
radar pulse. The longer the pulsewidth the
greater the direction range capability, however
range accuracy and range resolution are re-
duced.
Pulsewidth can be selected to short or long on
the 1.5 and 3 nautical mile ranges.
1. Press the [MENU] key.
2. Select “OTHER MENU” and press the
[ACQ/ENTER] key.
64
[ OTHERS ]
Select item by T-ball
and press ENTER key.
1 . Panel Dimmer
2 . Mark Brill
3 . HD Mark
4 . Characters
5 . Trail Tone
6 . Pulselength
7 . Noise Reject
8 . Trail Time
9 . Tune
10. WPT Mark
11. EBL Ref
12. VRM Unit
13. Watchman
14. STBY Disp
15. Guard Mode
16. Own Position
17. Cursor Posi
18. Alm Sense LV
19. Dead Sector
20. Range
21. 2nd Rej
22. Self Test
23. Installation Setup
4
4
4
4
20min
1
1
1
1
Single
Short
Off
15sec
Auto
Off
Rel
nm
Off
Norm
In
L/L
R/B
Low
Off
1/8 1/4
Off
2
2
2
2
Multi
Long
On
30sec
Manual
On
True
km
5min
Econo
Out
TD
L/L
Med
On
On
1 1.5 1/2 3/4
3min 6min 15min 30min Cont
2 3 4 6 8 12 16 24 36 48
*Max. range is;
FR-7062: 64
FR-7112: 72
FR-7252: 96
72 96
* * *
†: Not displayed on N-type radar; VRM unit is fixed for nm.
†
TX
3
3
3
3
1min
sm
10min 20min
Nav
Hig
Figure 3-5 OTHER MENU
3. Select “6. Pulselength” by operating the
trackball.
4. Select Short or Long by operating the
trackball.
5. Press the [ACQ/ENTER] key.
6. Press the [MENU] key to close the menu.