ASP is an effective tool in combating noise. In sonar terms, noise is any undesired signal. It is caused by electrical and mechanical sources such as bilge pumps, engine ignition systems and wiring, air bubbles passing over the face of the transducer, even vibration from the engine. In all cases, noise can produce unwanted marks on the display.
The ASP noise rejection feature is especially useful because it typically lets you operate the boat at all speeds without adjusting the sensitivity or other controls.
The ASP feature has three settings — Off, Low and High. When first turned on, noise rejection is set on low. If you have high noise levels, try using the high ASP setting. However, if you are having trouble with noise, we suggest that you take steps to find the interference source and fix it, rather than continually using the unit with the high ASP setting.
There are times when you may want to turn ASP off. This allows you to view all incoming echoes before they are processed by the ASP feature.
To change the ASP setting, press MENU DOWN until NOISE REJECT appears. Use the up and down arrow keys to select the desired setting, then press PWR to clear the menu.
ALARMS
The sonar unit has three different types of alarms: fish, shallow and deep.
Fish Alarm
The Fish Alarm sounds a tone when a fish symbol appears on the screen. The default setting is off, and the Fish I.D. feature must be turned on for fish alarms to work.
To turn Fish I.D. on, press MENU until the FISH ID menu appears. Press UP ARROW to select ON, then press PWR. Then, press MENU until the FISH ALARM menu appears. Press UP ARROW to
select ON, then press PWR.
To turn off the fish alarm without turning off fish symbols, press MENU DOWN until FISH ALARM appears. Press DOWN ARROW to select OFF, then press PWR to clear the menu. Repeat the above steps to turn the alarm back on, but press UP ARROW to select ON before clearing the menu.
Depth Alarms
The depth alarms are triggered only by the bottom signal. No other echoes will activate these alarms. The depth alarms consist of a shallow and a deep alarm. The shallow alarm sounds an alarm tone when the
35