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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.
Noise Reject menu.
The ASP feature has four settings — Off, Low, Medium and High.
When first turned on, noise rejection is set on low. If you have high
noise levels, try using the medium or 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
N
OISE
R
EJECT
ap-
pears. Use the up and down arrow keys to select the desired setting,
then press
PWR
to clear the menu.
ALARMS
The sonar unit has two different types of alarms, fish and depth.
Fish Alarm
The Fish Alarm sounds a tone when a fish symbol appears on the
screen. The default setting is on, but the Fish I.D. feature must be
turned on for fish alarms to work.