Specifications
TRANSDUCER SELECTION
Eagle
offers
you
the choice
of transducers with either an B de-
gree
or 20
degree
cone
angle
that
will
interchange
with
any
of
our
192 kHz sonar units. In other
words,
any
Eagle
sonar instru-
ment can be used with
any
Eagle
transducer of the same
frequency
without
retuning
of
any
kind,
and no loss of
performance.
However,
the use of
any
other
manufacturer's transducer will re-
sult in
a loss of
performance.
Now
you
can select the trans-
ducer
design
and cone
angle
to
best
fit
your specific
needs. Gen-
erally,
wide cone
angle
transduc-
ers
(20
degree)
are
ideally
suited
for
operating
in shallow water or
at medium
depths.
The 20
degree
cone
angle
allows
you
to see
more of the underwater world. In
15 feet of
water,
the 20
degree
cone
angle
allows
you
to see an
area of the bottom that's
approxi-
mately
6 feet across. The 8
degree
transducer covers
only
about a 2 foot circle.
Figure
3
Thus, you
would use a 20 de-
gree
transducer when
looking
for
fish or
structure,
to
easily
find
drop-offs,
and to see fish that are
around
you.
. .
not
just
below
you.
However,
the 20
degree
trans-
ducer
won't
penetrate
to
greater
depths
as well as the 8
degree
transducer,
nor will it show a
sharp drop-off
as well. In a
deep-
water environment
(100
feet or
deeper)
the narrow cone
angle
is
more
desirable because it can
more
accurately
detect
the loca-
tion of the fish or
drop-off
in
deeper
water. Since the
sound
energy
is concentrated in a
smaller
area,
it can
reach to
deeper depths.
Both the 8
degree
and the 20
degree
Lowrance transducers
give
accurate bottom
readings,
even
though
the bottom
signal
is much
wider on the 20
degree
model be-
cause
you
are
seeing
more of the
bottom.
Remember,
the shallow
edge
of the
signal
shows
you
the
true
depth.
The rest of the
signal
tells
you
the
composition
of the
bottom,
i.e. whether
you
are over
a
soft or hard
bottom,
etc.
Ill
BASIC OPERATION
On-Off and
Sensitivity
Control
—
Rotate the
Sensitivity
knob
50'
clockwise to turn the unit
on. The
Sensitivity
knob works much
like
the volume control on a
radio,
that
loo,
is,
weaker
signals
will be
detected
with
higher settings
of the knob.
When
cruising,
or at other
times
when
just simple
bottom contour
information is
desired,
the Sen-
sitivity setting
can be low. In
deep
water or over
soft,
muddy
bot-
200
toms, (which
produce
weak
•8°at3db
echos),
the
setting
will have to
be
higher.
into
the unit and the transducer is
in
contact with the water.
Symptom
The unit is
"ON",
but
paper
does
not move.
What
To Do
Tape paper
to cardboard
spool
on
take-up post.
Symptom
Recorder marks
are faint or dim.
What To Do
Clean
viewing
door;
replace
the
stylus;
check
battery
connections.
Symptom
Recorded
marks are
very heavy;
paper
is torn
by stylus.
What To Do
Bend the
stylus
slightly
to reduce
pressure
on
paper.
VI
ADVANCED OPERATION
Surface
Clarity
Control
(SCC)
The surface
markings
at the
top
of the chart
paper can,
at
times,
extend
many
feet below the sur-
face. This
often interferes with fish
signals
or
other
targets.
This is
called
Surface Clutter and is
caused
by
algae
and
plankton,
air
bubbles caused
by
wave action or
boat
wakes,
bait
fish,
or
tempera-
ture inversions.
The surface clutter
markings
can be reduced or eliminated
by
using
the MARK/SCC
control
key
on the front
panel keyboard.
To use the
5CC, press
key
1
thru 4 and then
the MARK/SCC
key.
1 has a
minimum effect on
surface
clutter,
4 has the max-
imum effect
on
reducing
surface
clutter. 2 and 3
have intermediate
effects.
The amount of SCC that is
used is
printed
at the bottom of
the
chart
paper.
If one level of
SCC is
used,
then S-i is
printed.
Two
levels, S-2,
etc.
The effect on surface clutter
should
immediately
be seen.
Use
only
the amount of SCC
required
to
reduce the
clutter,
as fish
sig-
nals can be eliminated
by
using
this
method,
also.
If
you
wish to turn
the SCC
function
OFF,
simply press
0-MARKISCC and the SCC
function will be disabled.
Example:
ENTER A SCC
LEVEL OF 2.
Press:
2
-
SCC
Result:
(See Figure
37.
4
17
Cone
Angle
ClameIer
, . I
line
04 22
I
bin 2' 51 I
1220
2' II
I
-
12----
-----——-—.—-.——.-
-
29———-—-
--..-.__—,——..
'lB
—2 L!
.
Th-
- -
Figure
37
SCC "2"
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