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press the RANGE button, and highlight MANUAL DYNAMIC. Now start pressing the
UP/DOWN buttons to get to the desired DYNAMIC DEPTH range. If the water is 21 feet
deep, you would select 22 feet. Now the DYNAMIC DEPTH has created a 0–22 foot
range, utilizing virtually 100% of your display.
We offer the manual range functions because in some circumstances the AUTO range functions can
behave erratically, especially in situations where there is heavy weed growth, uneven bottom contours,
large schools of fish, or very shallow water. If erratic behavior is encountered in these circumstances,
the user should manually select a fixed range. We recommend Ice Fishing in a Manual range selection.
o
Zoom
First, activate one of the Zoom displays [vertical zoom or graph] by pressing the panel
number, then Marcum sonar, then the Zoom display of your choosing. Now press the
settings button in the upper right corner, then press Marcum sonar. A menu window
will open, and pressing zoom will open the zoom sub-menu. Pressing auto will put the
unit into bottom lock zoom mode, where it will automatically lock onto the bottom and
display a selected portion of the water column above it.
Manual Zoom will allow the user to zoom in on any portion of the water column. Select
“Zoom Mode” and then choose “Manual”. Once “Manual” has been selected, choose
the size of zoom window that you prefer [5’, 10’, 20’, 40’].
Next, choose the zoom depth. This number will determine the uppermost portion of the
water column that will be displayed. For example, if a 10-foot zoom window is chosen
and the zoom depth is set for 21 feet, the portion of the water column starting at 21
feet and going down to 31 feet will be zoomed.
o
Sensitivity
Controls the amount of sensitivity required by the unit to pick up objects like bottom,
weeds, fish, or lures and jigs. The lower the number, the less sensitivity; conversely
higher numbers mean more sensitivity. Can be used in conjunction with Target Adjust to
fine tune your display to your preferences.
o
Interference Rejection
The Interference Rejection system is designed to suppress signals from other sonar units
being used within close proximity. When other sonar units are causing interference to
the display, activate the IR feature by pressing the right arrow to the desired level.
Interference is indicated by unusual signals or clutter flashing or scrolling across your
display.
The correct level of IR will be achieved when the display is clear of display clutter. In
some extreme cases, clutter will be greatly reduced but not totally eliminated.
Anytime two or more sonars are being operated in proximity to each other, there is the
potential for interference. Deep water and hard bottom will increase the likelihood that
one or more of the competing sonars will experience interference. Besides
experimenting with different levels of IR, the anglers experiencing interference can also
