Setting Watchman Stand-By Interval; Suppressing Second-Trace Echoes - Furuno NAVNET GD-1920C Operator's Manual

2. RADAR OPERATION
Note: When the watchman is activated and no guard zone is active, the message "PLEASE
SET GUARD ZONE. PUSH ANY KEY TO CONTINUE." appears. Press any key and then
set a guard zone.

2.23.3 Setting watchman stand-by interval

The watchman standby interval, that is, the number of minutes the radar is in standby, can
be set to 5, 10 or 20 minutes as follows:
1. Press the MENU key.
2. Press the RADAR DISPLAY SETUP soft key.
3. Select WATCHMAN TIME, then press the EDIT soft key.
WATCHMAN TIME
5 minutes
10 minutes
20 minutes
Watchman time window
4. Select time desired, then press the ENTER soft key.
5. Press the MENU key to close the menu.

2.24 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.
To activate or deactivate the second-trace echo rejector do the following:
1. Press the MENU key.
2. Press the RADAR DISPLAY SETUP soft key.
3. Use the Trackball to select 2ND ECHO REJECTION, then press the EDIT soft key.
4. Choose ON or OFF as appropriate, then press the ENTER soft key.
5. Press the MENU key to close the menu.
2-24
Tx repetition
Actual range
Second-trace echoes
Second-trace
echo
False echo
range