Furuno FR-1500 MARK-3, User Manual

Page: 32 / 125

-1.18-
Note:
To create a target alarm zone having a 360-degree coverage around own ship, set
point B in almost the same direction (approx. ±3°) as point A and press the [TGT ALARM] key.
Two alarm zones can be set as described above. To change the active alarm zones, do steps 1
through 4 in the above procedure. (When both alarms are prepared the active alarm indication is
circumscribed.)
1.22.2 Acknowledging alarm
A target entering the ALARM zone produces both visual (flashing) and audible (beeping) alarms.
To silence the audible alarm, press the [AUDIO OFF] key shortly. ACK replaces IN (or OUT).
This will deactivate the audible alarm but will not stop the flashing of the target in the target alarm
zone. To reactivate the audible alarm, press the [AUDIO OFF] key again.
To silence the audible alarm, you may press the [AUDIO OFF] key. However, in this case, the label
ACKN does not appear.
Hold the [AUDIO OFF] key depressed for at least 5 seconds to disable the target alarm.
Note:
The target alarm is given to targets having a certain level of echo strength. This level does
not always imply a landmass, reef, ships or other surface objects but can mean returns from the
sea surface or precipitation. Properly adjust the GAIN, A/C SEA, and A/C RAIN controls to reduce
noise to avoid generation of the guard alarm against false targets.
On the R-type, an inward or outward target alarm can be selected on the TGT ALARM menu. On
the IMO type, only the inward guard alarm is available. The inward guard alarm generates visual
and audible warnings when a target enters the target alarm zone from any direction. The outward
target alarm is produced when a target leaves the target alarm zone. (This is not a target alarm by
definition but an anchor watch, which some users find valuable.)
Inward alarm (IMO-type and R-type)
The radar causes an alarm when a
target violates the TAZ.
Outward alarm (R-type radar only)
The radar causes an alarm when a target
leaves the TAZ (Anchor watch).
1.23 Off-centering (shift)
Own ship position, or sweep origin, can be displaced to expand the view field without switching to a
larger range scale. The sweep origin can be off-centered to a point specified by the cursor, up to
75% of the range in use in any direction.
This feature is not available on the longest range scale or in the true motion mode. The number of
range rings increases keeping the original range intervals unchanged. To off center the radar
picture:
1. Place the cursor at a position where you wish to move the sweep origin by operating the
trackball.
2. Press the [SHIFT/ZOOM] key with a touch-and-release action. Then, the sweep origin is
off-centered to the cursor position. However, the heading line is left in the same position.
3. To cancel off-centering, press the [SHIFT/ZOOM] key again.