Furuno 1942 MARK-2 manual Watchman, Silencing the audible alarm, How watchman works

3.Operate the omnipad to set the cursor on point C (or D). See Figure 3-8 (3).

4.Press the [GUARD] key. The asterisk dis- appears. See Figure 3-8 (4).

		Asterisk blinking
	Guard zone		* G (IN)
	to set	A
A
		D
B		C

Drag cursor here.

(1) Mentally create			(2) Drag cursor to
the guard zone to set.			top left corner of
			zone and press
			[GUARD].
	G (IN)			G (IN)
		Guard
		zone			C
			Drag cursor
			here.
(4) Guard zone			(3) Drag cursor to
completed.			bottom right corner
			of zone and press
			[GUARD].

Figure 3-8 How to set the guard zone

Silencing the audible alarm

Any radar targets violating the guard zone will trigger the audible alarm. You can silence the audible alarm by pressing the [GUARD] key. When this is done, “G(ACKN)” replaces “G(IN).” This means the alarm is acknowl- edged. Press the key again to reactivate the alarm. You may select minimum echo stregth which triggers the guard alarm. This can be done at “20, Alm Sence Lv” on the “OTHER MENU.”

Cancelling the guard zone and guard alarm

Press and hold down the [GUARD] key until the guard zone disappears.

Notes on the guard alarm

¡The alarm is a useful anti-collision aid, but does not relieve the operator of the re- sponsibility to also keep a visual lookout for possible collision situations.

¡When the radar range is less than one half of the guard zone range, the guard zone disappears and “G (IN)” or “G (OUT)” appears in inverse video. If this happens, raise range to re-display the guard zone.

¡A target echo does not always mean a landmass, reef, ships or surface objects but can imply returns from sea surface or precipitation. As the level of these returns varies with environment, the operator should properly adjust the A/C SEA, A/C RAIN and GAIN to be sure the alarm sys- tem does not overlook target echoes.

3.8 Watchman

The watchman function periodically transmits the radar for one minute to check for targets in a guard zone. If it finds change in the zone from the previous transmission it transmits the radar continuously. This feature is useful when you do not need the radar’s function continuously but want to be alerted to radar targets in a specific area.

Tx St-by Tx St-by

1 min 5, 10 or 1 min	5, 10 or
20 min	20 min

Watchman starts.

Figure 3-9 How watchman works

How watchman works

When the time selected for the watchman rest period has elapsed, the radar automatically transmits for one minute to check the condi- tion inside the guard zone. If there is no change, the radar goes into stand-by. (“WATCHMAN” appears during stand-by.) If there is change, the radar sounds the audible alarm, cancels the watchman function and transmits continuously.

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