16(2) Change of the alert levelMenu screenMove to RADAR SET-UP, Move to ALARM LEVEL, press, Move to 1 / 2 / 3 / 4 / 5 / 6 / 7 ,pressBack to PPI screen[ Ref. ] ☞ Alarm level 1 ~ 7 represents ImageLevel (ECHO Level) sounding the alert.1 Being selected, it gives the alert sound to allimages shown in Screen.7 Being selected, it gives the alert sound to thestrongest image displayed in the screen.(3) Occurrence and Stoppage of the alertsounda) When pressed the button, the alert soundis stopped.b) If you press the button again, alert soundis coming.(4) Termination of the alert When button is pressed, all alerted status isterminated.4.3.8. To eliminate/display the scaleof Range Ring(1) Press button three times. The brightness of Range Ring is adjusted in 3steps.4.3.9. To remove the RadarInterferenceATTENTION※ When using the function of IntereferenceRemoval, weak image such as a dangerousthing may happen to be removed.※ Stop the function of interference removalwhen you see Radar BEACON an SART signal. Radar Interferene means Micowave transmited byother ship’s Radar is displayed on PPI screen, whichis directly affecting to own ship’s Radar air line.(1) Whenever pressing button, it marks withIR-1, IR-2, IR-3 in order in the top-right screen.(2) IR-3 is the status that shows Radarinterference a lot. (IR=INT REJECT)<Before Interference Removal>IR-1<lAter Interference Removal>4.3.10. To eleminate the Ship’sHeading Line(1) Press button.a) Ship’s Heading Line is indicating own ship’sheading direction.b) When you are pressing buttoncontinuousely, ship’s Heading Line is off and itis displayed again when you hand the key off.Inteeference Removal FunctionRadar interefence