Raymarine DS400X, Owner'S Handbook Manual

Page: 47 / 92

Chapter 4: Main Menu 37
Second Echo Rejection
A so-called “second echo” can caused by the sonar signal returning from the
bottom, reflecting off the water’s surface, bouncing off the bottom again and
returning. This option helps eliminate identifying a false bottom.
Select from the following:
•
OFF
, which offers no rejection
•
LOW
, which provides minimal rejection by slightly reducing the ping rate
•
HIGH
, which offers the greatest signal rejection by decreasing the ping
rate further
The default setting is
LOW
. Only set this setting to HIGH if you notice second
echoes appear on your display.
Power
The Power setting provides adjustment of the transducer signal. Select from
the following:
•
AUTOMATIC
, in which the sounder automatically determines the optimal
power setting based on the current depth, speed, and (bottom) signal
strength
•
MANUAL
, in which the power is increased or decreased in 10% incre-
ments.
The default setting is
AUTOMATIC
.
Max. Ping Rate
The setting determines the maximum number of sonar pulses, or pings, the
transducer emits per second. You can set Max Ping Rate anywhere between
5–30, in increments of 1.
The default setting is 30 pings per second, the maximum. You can reduce this
number down to a minimum of 5 pings per second, if necessary, to help
reduce second echoes.
ZOOM...
Zoom enlarges all or part of the scrolling bottom display at x2, x3 or x4
magnification. You can select automatic zoom so the sounder keeps the
bottom in the lower portion of the zoom window or manually pick the area to
be zoomed. The ZOOM sub-menus are: