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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.
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
N
OISE
R
EJECT
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
F
ISH
ID
menu
appears. Press
UP ARROW
to select
O
N
, then press
PWR
. Then,
press
MENU
until the
F
ISH
A
LARM
menu appears. Press
UP ARROW
to
select
O
N
, then press
PWR
.
To turn off the fish alarm without turning off fish symbols, press
MENU
DOWN
until
F
ISH
A
LARM
appears. Press
DOWN ARROW
to select
O
FF
, then
press
PWR
to clear the menu. Repeat the above steps to turn the alarm
back on, but press
UP ARROW
to select
O
N
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
bottom goes shallower than the alarm's setting. The deep alarm sounds
