Menu Functions - Humminbird 400TX Operation Manual

Range, Depth Alarm and Zoom. See the detailed description of each function for further
explanation.

Menu Functions

Sensitivity. The Sensitivity function controls the sensitivity of the sonar
receiver. The 400TX automatically adjusts the level of receiver
sensitivity 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 through +5) enables the
unit to display the information from progressively smaller sonar returns. By decreasing the
sensitivity (-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 suspended 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
select.
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
onscreen indefinitely. If you need to make an
additional adjustment, press the UP ARROW or
DOWN ARROW button.
Depth Range. The Depth Range function controls the vertical
distance displayed on the graphic area of the display. There are nine
depth ranges available. The top of the range is always 0, or the
surface of the water. Ranges of 0-15', 0-30', 0-60', 0-120', 0-180', 0-
240', 0360', 0-480', and 0-600' are available. In the metric version,
ranges of 0-5, 0-10, 0-20, 0-40, 0-60, 0-80, 0-110, 0-150, and 0-185
meters are available. The range that positions the bottom depiction
closest to the bottom of the screen, will best utilize the available
display resolution.
The 400TX automatically adjusts the depth range depending on the
depth of the water. The unit tries to maintain the bottom depiction
about 2/3 down the total range (for example, in 20' (6m) of water, the
0-30' (0-10m) range would be selected). This provides the best
display resolution and therefore the best target separation possible.