Menu Functions
Sensitivity.
The Sensitivity function controls the
sensitivity of the sonar receiver. The 250DX
automatically adjusts the level of receiver sensi-
tivity based on a number of factors including
the depth of the water and the level of noise
present. Noise can be caused by other electronic devices, engines, trolling
motors, propeller cavitation and hydrodynamic flow among others.
The user has the option of adjusting the Sensitivity higher or lower based on
personal preference. You can select one of 11 sensitivity settings from -5 to +5.
A setting of 0 (factory setting) has no effect on the automatic sensitivity control.
Increasing the sensitivity (+1 t5) enables the unit to display the informa-
tion from progressively smaller sonar returns. By decreasing the sensitivity bias (-
1 through -5), the unit effectively filters small sonar returns.
In murky or muddy water, it is often helpful to reduce the sensitivity. This
prevents the display from being cluttered with sonar returns from debris or sus-
pended particles. In very clear or very deep water, it may be helpful to increase
the sensitivity since even the smallest sonar return may be of interest to the user.
To adjust Sensitivity, press MENU
repeatedly until the Sensitivity heading is
displayed. When the Sensitivity menu
appears, use the UP ARROW to increase
the sensitivity, or the DOWN ARROW to
reduce sensitivity. To sequence through
the available settings, press and hold
either ARROW button. Release the button
at the setting you want to change.
After an adjustment is made, the menu
disappears and the new sensitivity setting
is in affect. If additional time is needed to
study a menu, press and hold the MENU
button and the menu will remain on-
screen indefinitely. If you need to make an
additional adjustment, press the UP
ARROW or DOWN ARROW button.
14
USING THE 250DX
MENU FUNCTIONS
High(+) Sensitivity Low(-) Sensitivity
Sensitivity at “0”
