Humminbird Legend 1000 - Manual (Page 12)

10
Surface Clutter
S URFACE C LUTTER eliminates
most sonar returns
near the water surface
caused by trapped air, boat wakes and
temperature inversions. Most surface clutter
appears on the display because the strongest
sonar returns come from the shallowest objects.
The
L EGEND 1000 S ERIES
uses a sophisticated feature
called TVG (Time Variable Gain) to overcome
surface clutter and counteract the effect of
depth on sonar return strength. The level 1
setting is optimal for making sonar information
from all depths appear uniformly. Many users,
however, prefer to see more surface clutter than
this setting shows. Selecting a higher number
shows more surface clutter, but sonar returns
nearest the surface will appear more intense
than they actually are.
The S URFACE C LUTTER setting is retained in memory
after the L EGEND 1000 S ERIES
is turned off. The factory
setting is 4 .
White Line
W HITE L INE activates and
adjusts a feature
which changes how
the
L EGEND 1000 S ERIES
draws the bottom
contour and
structure, and also
shows fainter sonar
returns more clearly.
When a
W HITE L INE
setting of 1 to 8 is
selected, a light gray
band highlights the
strongest sonar returns within the sonar image
and makes a distinctive outline along the
bottom contour, structure and fish. Selecting a
larger numeric setting increases the width of the
band and makes fainter sonar returns more
noticeable, but the
L EGEND 1000’ S
ability to show
subtle differences in bottom composition and
structure is reduced. Selecting a smaller
numeric setting narrows the band and shows
greater variation in bottom composition.
Selecting
O FF
turns the W HITE L INE
feature off.
The W HITE L INE
setting is retained in memory after
the L EGEND 1000 S ERIES is turned off. The factory
setting is O FF
.
Filter
F ILTER ( D EEP Models only)
turns the filtering
algorithms on and off.
Select
O N to filter excess sonar noise. Select O FF
to show the greatest amount of sonar
information.
The F ILTER
setting is retained in memory after the
1000 Deep/1005 Deep is turned off. The factory
setting is O N
.
Depth Alarm
D EPTH A LARM
activates a
shallow water depth
alarm. The alarm will
sound when the digital depth becomes equal to
or less than the setting. The tone sounds at a
rapid rate for several seconds and then sounds
intermittently until the boat moves to deeper
water. The
D EPTH A LARM
can be muted by pressing
the C ONTROL P ANEL knob ; once muted, the alarm will
not sound again until the boat moves to water
deeper than the
D EPTH A LARM
setting. International
models have Depth Alarm settings in metres
and fathoms.
Note: Remember that depth is measured from the
transducer, not from the surface of the water.
The D EPTH A LARM
setting returns to factory default
after the L EGEND 1000 S ERIES is turned off. The factory
setting is O FF .
Temp Alarm
Temp Alarm activates
an alarm that sounds
when the surface water
temperature changes to fall within or outside
selected ranges. These temperature boundaries
help define bodies of water that are comfortable
USING THE LEGEND 1000 SERIES
SURFACE CLUTTER / WHITE LINE / FILTER / DEPTH ALARM / TEMP ALARM
White Line Screen