TRANSDUCER SELECTION
Lbwrance offers you the choice
of transducers with either an 8 de-
gree or 20 degree cone angle that
will interchange with any of our
192 kHz sonar units. In other
words, any Lowrance sonar instru-
ment can be used with any Low-
rance 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 v4ater 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
arouhd you. . . not
lust
below you.
However, the 20 degree trans-
ducer wont penetrate to greater
depths as well as-tjie 8 degree
transducer, nor will t 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 df 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 controi on a radio, that
100' 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 viewtng 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, 5-2, 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 5CC
function OFF simply press
0-MARK/SCC and the 5CC
function will be disabled.
Example: ENTER A SCC
LEVEL OF 2.
Press: 2 - SCC
Result:
(See Figure 37.)
4 17
Depth S 23'
'2 Itt. tIn.
520 14 31
III 21 13
224 20 II — 12— ———.-- ——-—-—-—--——---
—lie
bO—--S—2 U ——-—----——---bO—--fl----—-
Figure 37 5CC 11211
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