Lowrance electronic LMS-339cDF iGPS GPS Receiver User Manual


 
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3. To enable the Empty Alarm, highlight the
EMPTY ALARM Enabled box
and press
ENT to turn on (check) the alarm. Press to the Percent box
and press
ENT. Use the keys to select the first number, then press
to move to the next number. When the desired percentage has been
entered, press
ENT.
Tip
You do not have to set both the Full and Empty alarms. Choose Full
and Empty alarms or activate them individually.
Calibrate Speed
The speed sensor can be calibrated to compensate for inaccuracies. Be-
fore you change the setting, first calculate the percentage that the
speed is off. You will enter this percentage in a moment.
For example, if you figure the sensor is reading 10 percent faster than
actual speed, you will enter – 10 in the calibration window. If the sen-
sor is reading 5 percent slower than true speed, you will enter + 5 in
the window.
A good way to gauge your speed sensor's performance is to compare its
reading with the ground speed measured by your unit's GPS functions.
When you make a run to compare GPS ground speed to speed sensor
speed, perform your test in relatively calm water free of current, if pos-
sible. (Unless, of course, you are taking the speed of current into con-
sideration when making your calculation.) After you have a correction
figure, here's how to enter it:
1. Press
MENU|MENU| to SONAR SETUP|ENT| to CALIBRATE WATER
SPEED|ENT.
2. Enter the number you calculated earlier. Press to change the
first character (+ or –), then press to move the cursor to the next
number and repeat until the percentage is correct, then press
EXIT.
Chart Speed
The rate that echoes scroll across the screen is called the chart speed.
The default is maximum; we recommend that you leave the speed set
there for virtually all fishing conditions.
However, you might consider experimenting with chart speed when you
are stationary or drifting very slowly. You may sometimes achieve bet-
ter images as you slow down the chart speed to match how fast you are
moving across the bottom.
If you are at anchor, ice fishing or fishing from a dock, experiment with
a chart speed around 50 percent. If you are drifting slowly, try a chart
speed around 75 percent. When you are stationary and a fish swims