Eagle MODEL SILENT SIXSIXTY INSTALLATION INSTRUCTIONS

HOW TO OBTAIN

Electronics will

Eagle
Eagle parts

write us at the address below before
to save

do have to return the unit for
problem

testing

you

that

and

should

the

inconvenience of

you

repair

provide quek

ever

you

are

of

your depth

Mail to: EAGLE ELECTRONICS

having

require

sending

service,

with the unit. This will assist us in the

sounder.

P0. BOX 669

CATOOSA,

If
If

Should
sounder,
promptly

EAGLE.

live out of the state of

you

live in the state of

you

Oklahoma,

Oklahoma,

SCHEMATIC DIAGRAM & PARTS LIST

desire a schematic and

you

send

Please be sure and

to the address above

$1.00

give

us the model and serial

SERVICE

and efficient service

it. If

sending

please

call collect 918-266-5373.

parts

do

you

require service,

in the unit. We

the unit back for

enclose a letter

OKLAHOMA 74015

call 1-800-331-2301.

list for

and

your

it will be

with

repairs.

EAGLE

mailed to

number of

genuine

call or

be able

may

stating

If

you

the

depth

you

your

41

EAGLE

MODEL SILENT

SIX/SIXTY

INSTALLATION INSTRUCTIONS

EAGLE ELECTRONICS

LImO IN U.S.A.

9 66-0087-01

- -

EQ. BOX

A DiviiOh Ol

I

Lcwrance Electronics Inc

669, CATOOSA,

OKLA. 74015

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INTRODUCTION

Thank

proof
believe that it is the finest unit

available

right

sion

tolerances.

lb

fully enjoy

this

equipment

suggest

ual

thoroughly

tempt
this

product.

Please fill out the

and mail it to EAGLE ELEC-

TRONICS. This will

your

We

suggest

original

was

shipped in,

needs to be returned to the fac-

for

tory

tainer will be available.

for

you

EAGLE

here in

that

selecting

depth

manufactured

today,

the U.S.A. to

the

advantages

brings

read this man-

you

before

sounder. We

to

any

at installation or use

warranty

1

year

FULL

that

carton that the EAGLE

repairs,

register

warranty.

you keep

so that if it

a suitable con-

a water-

preci-

you,

at-

of

card

the

ever

POWER CONNECTIONS

Power for the
supplied by

electrical
picked up

power buss,
lems with electrical

which is indicated
flashes on the

we

minimized
directly

Figure

If a

quired,
cable available at

system.

to the

1.)

longer power

use

or electrical

should be soldered. If this can't

be

Simple twisting

done,

use

result in intermittent

connections which can cause in-
terference.

electrical

tape.

SPECIFICATIONS

Dimensions with knobs and
Dial 0-60

Voltage

Current

Drain 250

gimbals

Pulse Width 200-1000
Output

Power 200 watts

. 711 x 8W x 61)

(outer),

12 volts D.C.

volts)

ma.,

(typical)

25 wafts RMS

4AMP FUSE

sounder is

depth

the boat's 12-volt DC

at an

but if

dial,

Power

accessory

may

or

have

you

interference,

extraneous

by

it can be

prob-

by connecting power

battery

ordinary

supply

crimp-type splices.

'Ihpe

0-360

one echo

cs,

adjustable

peak

(See

cable is re-

#18

hardware

any

store.

of

splices may

power

all

splices

(inner)

(operates

to

peak

lamp

Splices

with

10-15

be

FISH SIGNALS

Here are some
help you

that are

Eagle:
signal

a

fish
near the

many thin, rapid
signals
game

ent under

lows

If

per

your Eagle, a single
deep

proximately
miles

second and the diameter of the

circle covered
is

that

by

half a

feet
approximately

This is a

because fish often school in a

horizontal

rather

exact

and a

A

while a small fish returns

narrow one. A school of bait

or

minnows,

beneath

fish which are often

to feed on them.

are

you

hour while

will return

per

approximately

depth.)

a fish 15 feet

second,

deep

widely

level,

signal

things

understand the

displayed

fish returns a wide

big

surface,

the school of little fel-

cruising

hunting

one second.

hour is 4.4 feet

by

The

and from a fish 60

the

signal

two seconds.

good point

plane,

scattered in that

but not all

that lasts

has to be made

fish. Of
different

course,

levels,

that will

signals

on

your

nearly always

returns a

signals.

indicate the

at

great

Wide

pres-

three miles

fish with

fish 30 feet

a

signal

for

(Three

per

the transducer

four feet at

signal

deep

by

fish

even if

returned

would

would

last

to remember

sometimes

vertically,

longer

more than one

suspended

only

last

a

ap-

few inches

water,

nals at the

on the dial.

Remember, many

fish like
ledges,

But,
these

unable to show the fish because

the

sloping

such a wide

Many
pended

face and bottom
weather.

higher

will return different

corresponding depths

sharp drop-offs, rocky

and underwater cliffs.

as

your

spots,

kinds of fish remain sus-

between the water sur-

Crappies

lie at a uniform

or lower in the

kinds of

boat moves across

the

Eagle

bottom sends back

signal.

during

will

depth

a horizontal blanket in the

water.

A

school

big

in each direction and as

over it
constant

ing

low. A school of white bass isn't

likely

a school of

does,

you

signal, plus

a few inches above and be-

to cover such a

crappie

especially

and fall. The

these fish
spread vertically

The
bass and
be so

bass,

occupying

larger game

walleye

tightly grouped

crappie,

and the individual

at

being larger,
signals.

extend 100 feet

may

will

an almost

get

sometimes

in the summer

signals

a

to 10

(8

fish such as

aren't

or other

members,

return

stronger

sig-

game

will be

hot

usually

similar to

you pass

other flash-

area as

big

will show

greater

feet).

to

likely

as white

panfish,

To

12 Volts DC

(Positive)

1 18

Fig.

1

Ground

(Negative)

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TREES IN THE WATER

The

signals

dial shown here indi-
cate an underwater
tree

with

above it. The water is
50 feet
20 feet

deep,

tall,

fish are between ten
and 13 feet

Limbs at various
depths

vidual
count for the wide
band of
dial. Brush

similar, though

return indi-

signals

tall.

Bass and

often

hang

submerged vegetation,

not

only

face but down to
depths

depending
thermocline. To detect

them,

of 25 or 30

anchor bow and

stern so

move.

can't

signals
limbs.

come and

up

—

Signals

and down are fish

limbs don't move.

on the

a few fish

the tree

and the

deep.

and ac-

signals

near the sur-

your

indicate tree

on the

appears

not so

panfish

around

on the

boat

Constant

that

or shift

go

feet,

Fig.

IMPORTANT
When

installing

make certain that the in-line
fuse

supplied

tached to the red conductor of

the

power

power
will

the

ever shorted. A connector is

•

-
The

•

•

source as

protect

power

supplied

cable.

power

positive

cable is the red conductor.

power

The unit is
dental

damage
connections are

polarity

with the unit is at-

as close to the

cable

possible.

both the unit and

in case either is

cable

to attach the fuse

conductor

protected

reversals and no

will result if

wrong.

the unit will not work.

MOUNTING

21

The

stalled

tion which has a

The

mounting

overhead

the unit is

vicinity
position temporarily

sure it does not

readings.

•

changes,

cation. Note:

running

test. Holes
bracket allow wood screw or bolt

mounting.
Thread both knobs

the

mounting bushings

case. The
slots

•

the unit to
removing

These slots will clear the threads
of the

mounting bushing

sounder

depth

in

adjustable

convenient loca-

any

on either

supporting

to be located in the

of a

compass,

If

compass

choose

the unit must be

when

you

in the base of the

gimbal

in

the

top

"snap"

the

gimbal

gimbal knobs,

yoke permits

affect

of it that allows

the

power

cable,

This

to the

in the

acci-

from
battery

However,

can be in-

flat surface.

a bottom or

surface. If

run it in

to make

compass

heading

an alternate lo-

make this

partially

into

on the

bracket has

in without

knobs.

but net the

on the case.

The bracket sides will have to be
spread slighlty

bal

bushings,

their

original position

leased. Holes in the
bracket

bushings

align

to clear the

gim-

but will return to

when re-

with the

on the case and will

gimbal

gimbal

not allow the unit to come ofT

even in severe wave conditions.

lb remove the

loosen the
the bracket sides

and

case,

unit, simply

gimbal knobs, spread

the unit

pull

away

from the

and

up

out of the bracket.

TRANSDUCER
INSTALLATION

Two different

mounting

are available to install

EAGLE

transom mount or shoot-thru-
hull.
mount will work on most
we recommend that the shoot-

transducer,

Although

the transom

thru-hull method be used
on solid

transducer

single

but will not

fiberglass

signals

thicknesses of

go through porous

methods

your

either

hulls,

hulls. The

will

only

penetrate

fiberglass,

materials such as wood or foam.

The

signals

through

the

fiberglass

gardless
method is

should be made in an area that

has minimum water
air

bubbles,

also will not

air

pockets

of which

used,

or voids

laminations. Re-

mounting

the installation

turbulence,

and where the water

pass

in

is the smoothest.

The transducer cable should be
routed

cal

wiring.

ducer cable if

coil it and

stead,

from other electri-

away

Do not cut the trans-

it

is too

long.

store the excess

In-

in an unobtrusive area. 'frans-

ducer extension cables Model

TEC-10 are available that will

extend

the cable 10 feet. If the

17

2

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transducer cable needs to be ex-

tended

depth

will need to be
factory

Fig.

longer

sounder

for

2

than 10

feet,

and transducer

returned to the

re-alignment.

the

SIGNALS RETURNED BY A ROCKY BOTTOM

XD-2

1vo other transducers are
able for

sounder. Model XD-2 is a
speed plastic

EAGLE

your

unit that can be

avail-

depth

high

transom mounted or can shoot-
thru-hull. It works well on

vee hulls and aluminum boats.
The other transducer

3

Fig.

XD-3

special

it below

layer

is for

trolling

or shoot-thru-hull.

Ji

bracket
transducer that will

the severe cavita-

that is sometimes

on

aluminum boats. The

XD-3)
mounting

A
the XD-2

put

tion
present

model number for

XMB-2.

motor

is available

this bracket

deep

(Model

SHOOTING THROUGH
HULL

1.

Mounting

recommended for

inside the hull

hulls in an area that

have air bubbles in the resin

or

separated fiberglass layers.

The sonar
through

successful transducer installa-

solid

tion can be made on hulls

that have flotation materials

(such as wood or

tween

layers

the material is removed from

the

chosen area. For

for

is

some

manufacturers use a

of

layer
of balsa

outer

removing
fiberglass
core,

fiberglass,

wood,

layer

the inner

and the balsa wood

the

outer

fiberglass

signal

must

fiberglass.

foam)

of

fiberglass

and

of

fiberglass. By

layer

THE

is

does not

pass

A

in be-

if

example,

then a core

then the

of

layer

of

Fig.

20

The

from a

are

when
them.

signals

rocky

quite

you

The EAGLE's

dial will indicate

level of the bottom at

the correct

it will also show

thin

signals

below the wider main
bottom

explained by

signal.

returned

bottom

confusing

first see

the

depth,

but

clear

above and

This is

the fact

that the rocks near the

outer
of sound waves are
farther from the
transducer than those

in

the

the

tops

are closer than the

bottom.

This

shows

nals

school of

bluegills
twenty

nals are

those returned

fish.

of the cone

edge

center,

of the latter

drawing

the

typical sig-

indicating

white bass or

at a

depth

feet.

The

brighter

while

also

a

sig-

than

by

of

bait

3 16

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WIDTH OF SIGNAL INDICATES SIZE OF FISH

Small minnows or

bait fish
dial as

If

they

schooled

cover a
five to ten feet on the

appear

thin,
are

they may

depth

dial with a few

lines for individual.
minnows at the bottom

of the school. Your

EAGLE

even a

30
surface of the water.

of a
larger

flect the

will

single

feet beneath

Obviously,

fish offers a

big

surface to re-

signal

the back of a small

fish.

Consequently, yop

a wider and

get
brighter signal

dial

you
size of the fish from

the

you a good
you

big

ones.

even

and,

can't tell the exact

signal,

can

instantly

ones from little

on the

lines.

pale

tightly

of from

pale

indicate

minnow

the

the back

than

on the

though

it does

clue so that

give

tell

Fig.

19

fiberglass

exposed.

then be

epoxied

this outer

When

5.)

and

The transducer can

layer.

epoxy

coat

gel

directly

(See

is

poured

Figure

the hole and the transducer

placed
is still

no weak

2. The chosen area should be in

into the

structurally rigid

points

the hull

epoxy,

are made.

the aft one-third of the hull

on

planing

of the

intakes in
Water should flow

boats,

engines

displacement

and forward

and/or water

smoothly

in this area and it should
in the water at all

4

3. Before

the transducer to the

permanently bonding

speeds.

hull,

trial runs are recommended

to find the best

cation. Once an area has been

determined to be a

for the transducer to be

mounted,

the

area,

ducer in it face down. This

will eliminate air between

mounting

good spot

add some water to

and

place

the trans-

are

to

into

and

hulls.

face of the transducer and the

hull.
the unit and turn the

sounder

all

at

transducer until the best loca-

tion is
signal

minimum cavitation noise

(cavitation

turbulence and shows
narrow

sonar dial.)

4. If the chosen area

potential

stay

surface
face of the transducer with

100

grit sandpaper.

face must be flat

that the entire transducer

lo-

the

face is in contact with the

hull

Build

5.
caulking compound

ing clay
area of

not use PLAY-DOll) (See

Figure

transducer

the

Plug

on.

Operate

speeds

and move the

found for maximum

reception

is caused

signals

problems,

of the hull and the

to

prior

bonding.

depth

the boat

and

by

all around the

void of

is

sand the

The sur-

enough

a small dam out of

or model-

around the chosen

the

transducer. (Do

7.)

water

up

into

as

so

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15

4

Fig.

7

and bubbles.

or transducer should not in-

Also,

the

bracket

SIGNALS

FROM

STEEP,

ROCKY LEDGES

terfere with the boat trailer

or

hauling

3.

1'ypically,

should be located

of the boat.

the transducer

half-way

be-

tween the center of the
transom and the outside

of the hull.

(See

Figure

edge

8.)

6. Use a

epoxy

good quality two-part

to bond the

transducer

to the hull. Do not use

silicone rubber sealer or
adhesive that does not
rock hard. Follow the instruc-

tions on

and mix

a

small amount on the entire

face of the transducer and
pour

area

dam. Place the transducer

into the

turning

bubbles out

the

epoxy package

it

thoroughly.. Apply

1/16" thick level into the

contained

epoxy

by

by

pushing

to force all of the air

from under the

the

any

get

clay

and

transducer face. The trans-

ducer face should be

with the boat

minimum amount of
between hull and

Weight

until the

7. Route the transducer cable

hull,

the transducer

epoxy

along gunwales

from

power

TRANSOM MOUNT

1.

Loosely

cables.

attach the brackets to

parallel

with a

epoxy

transducer.

down

cures.

and

away

the transducer with the

hardware

2. Locate the bracket where the

flow of water is smoothest

provided.

with minimum turbulence

The transducer should be
mounted

or other hull

ribs,

that

can cause turbulence.

4. If

the hull deadrise exceeds 4

degrees,
mount on the centerline of

the hull or an

ducer should be used.
Figure

9

Fig.

5. Place the bracket

a shoot-thru-hull

9.)

away

from

stakes,

fittings

optiQnal

against

(See

transom in the selected area
with the bottom of the trans-

ducer flush with the bottom of

the hull.

Alignthe

transducer

with the bottom of the boat
hull

by

Mark

using a straight edge.

the transom for

drilling

-

trans-

the

Fig.

18

Your EAGLE trans-

lates time into dis-

tance — the farther

the sound waves
the

longer

go,

it takes

them to return to the
transducer and the

greater

shown on the dial.

Nowhere is this shown

more
when

over a

underwater

cliff;

inclined at a

the cliff is

the

depth

boat

steep,

than
rocky

ledge

clearly

your

either vertical or

Assume the

steep angle.

top

15 feet be-

passes

or

of

neath the surface of
the

water,

tom is 50 feet
Sound waves will

rough spots

all the

the

result,

and the bot-

on the cliff

down. As

way

the

deep.

hit

signals

on the dial will cover

an area

from
condition that could

easily

sion until

extending

15 to 50 feet — a

lead to confu-

under-

you

stand it.

5 14

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MUD BOTTOM CAUSES

When

ing fish,

adjusted properly

return a

signal

of

gravel, sand,

shell, you

times see the

disappear.
mean that

suddenly

tremely deep

the dial would have

shown the
with a wide band of

signals

Instead,

now above a mud bot-

tom. Mud absorbs the
sound waves. Thrn

the

gain.

signal may
from a bottom of de-

caying vegetation
under

will still show on the

however. Back

dial,

over a hard
you'll get multiple

signals.

are hunt-

you

with the

clear, bright

from a bottom

will some-

This doesn't

you

come to ex-

gain
to

or

signal

have

water

drop-off

in this case.

boat is

your

up

The bottom

be faint

water. Fish

deep

bottom,

—

Mud and

THE SIGNAL TO FADE

decayed vegetation

Fig.

17

the

mounting

of the slots

6. Mount

the

holes at the

in the bracket.

assembly

transom with two #10 screws.

the face of the trans-

Align
ducer with

hull with a

Tighten

7. Route the

the

depth

the bottom of the

straight edge.

all screws.

transducer cable to
sounder unit. Do

not cut the transducer cable.

If it is too

excess in an out-of-the-

the

location.

way

S. Make a

test run to determine

coil and store

long,

the results. Some boat hulls

require lowering

of the transducer 2° to

edge

6°. If the run was

drill

•

bottom of the slots and install

two

The transducer must be

•

against
results. After

fill
transom and the transducer
with

epoxy,

more holes in the

two

more #10 screws. Note:

the transom for

voids between the

any

caulking compound,

silicone adhesive.

or

the back

satisfactory,

locking

OPERATION

SENSITIVITY
"ON-OFF" KNOB

This knob
similar to the volume control

AND

operates

in a manner

to the

good

in

place,

top

on

a radio.

clockwise will

and

full counterclockwise
will turn the unit off.

the knob

clockwise manner will increase

Thrning

turning

in a continued

the receiver

weaker echos from

can and will be observed on the

dial. After

turn the unit on

ducer,

the

ing

clockwise. You will see the con-

sensitivity

stant surface

fore

long, you

—

signal
is ten feet

cates the bottom.
always

Continue
control toward the

will see

at ten feet if the water

show.

turning

a second bottom

at double the

20 feet. The sound waves have

or

hit

bottom,

surface

bounced

Over a firm bottom

crease

of the

down and

the

the knob

turn the unit

the knob

sensitivity

deeper

mounting

signal

will see another

deep.

the trans-

knob

at zero. Be-

This

It, too,

the

right

of the

depth

bounced

sensitivity

water,

up again.

back,

then

you

on,

back the

position

Thrning

and

water

turn-

by

signal

indi-

should

Sensitivity

and

you

signal

first,

hit the

can in-

until the

dial shows three or four bottom

signals

depth.

The

sensitivity

should

you

turn a

nearly

—

nal

at

multiples

always

steady

as

bright

regardless

of true

is

adjustable

set it to re-

bottom

as the zero

of

depth.

signal

and

—

sig-

'Ilirn

the knob counterclockwise when

to

you begin
tom

signal;

bottom
show

should be set to show a

bright

fishermen
sitivity

signal begins

fish the

bottom

control

the second bottom

the double bot-

get

clockwise when the

to fade. lb

strong,

signal

control

with

show-

sensitivity

signal. Many

prefer

to run the sen-

very high

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13

6

to insure

ing
the

underwater detail as well

fish.
NOISE

CONTROL

The noise

can be used

eliminate false
dial. These false
caused
from the boat's motor
bubbles

that

SUPPRESS

suppress

to cut down or

flashes on the

flashes can be

by ignition

passing

over the face of

they

control knob

interference

or

the transducet
Ilirning

the knob

creass the

press.

Always

suppress
increase in it cuts down

ability
rate

fish) close

Increasing

as

of the unit to show

signals

together.

noise

clockwise in-

amount of noise

use as

possible,

or

because an

objects

suppress

little noise

(such as

flfl)))flfl)flflfl)))fl

.( ((((

SIGNAL SENT BY LOCATOR BOUNCES

TARGET. TIME LAPSE INDICATES

11

Fig.

not affect the

unit.

RANGE

The

range

select either
0-60

fathom

Noise

Suppress

used to

pulling
fathom

pushing
scale to the 60'

sensitivity

control is used

the 0-60' or the

scale.

(360')

control knob

change

the

range

the

the scales.

knob

is

knob in switches the

the 0-60

out,

selected,

range.

see all

control in the 60'

as

range

outside 0-60 scale. With
control in the 60 fathom

position,

in fathoms on the outside

scale,

the

faceplate.

HOW

by

air

EAGLE DEPTH

SOUNIJER

The

ation of

sup-

Ranging.

ing

on the

sepa-

tracking
Sound travels at

4,800

water
mately 1,100

does

PRINCIPLE OF SONAR

((((

of the

to

The

is

By

through

( ((

(((

(

The
simplest

pulse
wave

transmitted into the water.

When this wave

ject,

of sound
known,

the transmitted

and

With the

received echo can be measured

and the distance to the

determined.

should be read on the

the

or

may

inside 0-360' scale on

position,

range may

be read in feet

the

the

be read

0-60

on

the

TO USE YOUR

word 'Sonar" is an abbrevi-

Sound,

World War II

enemy

feet

as

air.

( ( ((((((K

a sonar works in its

way

form is an

Navigation,

It

was

developed

as a means of

submarines.

approximately

second

per

compared

feet

DISTANCE TO TARGET

through

to

second

per

BACK FROM

electrical

is converted into a sound

the transducer and

by

strikes

it rebounds. Since the

through

the time

water is

lapse

signal

and

dur-

approxi-

an

ob-

speed

between

and the

object

HARD

Sand

bottom

16

Fig.

CLAY, SAND,

GRAVEL,

SHELL

BOTTOMS

Some

fish,

bass, catfish, walleyes,

and

crappies,

sionally

lie

the bottom. Even here
the EAGLE will show

them

as

you pass over,

provided
smooth

gravel.
shows a

with the

control

that a

signal

the bottom is

sand,

Figure

hard bottom

sensitivity

adjusted

strong

is

displayed

with two fish at 20
and 21 feet. A second

echo

that

as

the actual bottom

signal
sitivity

turned
to see

This is

the sound

flecting

tom,

be

may

is twice as

when the sen-

control is

up high enough

fish.

caused

waves re-

from the bot-

bounce

the water's
turn to the

reflect back to the
sonar unit.

fishermen

run

control

the

second bottom

nal

showing

that

underwater
well as fish.

The second

shown at 50 feet in
figure

the

sensitivity

very high

see all the

they

16.

prefer

including

occa-

on

right

or

shell,

16

so

bottom

displayed

deep

by

back from

surface,
bottom and

Many

re-

to

with

sig-

to insure

details as

echo is

7

12

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WEAK SIGNAL INDICATES GAIN TOO LOW

Fig.

12

Fish: 17 ft.

D,pth:

35

$

I

ak

t t

wArgRpIlOOF

EAGLE ELECThONOGG,,!G,!,.

EAGLE

"U:

The

trol on

might

sensitivity

your

be

compared

con-

EAGLE

to

the volume on a radio.

Thrn the

knob to the
you

ceiver

it to the left and

reduce it. This feature

is

provided

can use
over both
shallow water and
should

the
bright

shows on the

gardless
you

have
tom
will fail to show fish

sensitivity

increase the re-

sensitivity;

your

deep

always adjust

so that a

gain

bottom

of

fail to do so and

a faint bot-

only

signal

and

right

you

so that

EAGLE

and

signal

dial,

depth.

the dial

turn

Jf

you

you

re-

in the water between

the transducer and the

bottom. This condition

is shown in the draw-

above — the

ing

are there but

aren't shown on the
dial because the

fish

they

gain

is set too low.

Fig.

15

The

Eagle depth

mits a

wave

as well as humans)

high

(which

sounder

frequency

inaudible to fish

is

watet At the same

intensity
constant

on a disc driven

governed
lighted every

ter fires. This

reference

is used as a

measure
cator that
on. Even

flashes,

the human

nearly
The bulb
point

the

by

sound waves

and

returned from

water

bottom fire the

these

show the exact

—

neon bulb whirls

behind

speed

by

motor. The bulb

time the transmit-

provides

on

point

starting point

depth,

it

constant

the dial that indicates

on

depth.

the

length

and as

the

depth

eye

The

the neon bulb

sees

light.

point

though

happens

also flashes at the

of time it takes the

to reach the bottom

return. In

addition,

any object

between the surface and

echoes are also

or

any

bulb,
depth

number of fish

the dial which

trans-

sound

through

time, a high

the

at a

the dial

an

accurately

is

visual

a

to

an indi-

sounder is

so often that

it

a

as

is indicated

echoes

in the

too. Since

timed, they

of

any

—

fish

in

the water. And because the

sound waves from the transducer

down into the

go

row cone

angle,

a matter of a few

location as well as the

At a

depth

covers a circle that

mately

15 feet it is two feet

feet,
diameter is four feet wide.

gardless
sound ends at the bottom.

one foot

three feet

of

an echo is also returned

any object

ducer and the bottom.

water in a nar-

they tell,

feet,

of 10

feet,

in

diameter;

wide,

depth,

between

the cone of

the fish's

depth.

the cone

is

approxi-

wide,

the cone

from

the trans-

within

at

at 20

Re-

But

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11

8

As

a

will

dial until it
dial is calibrated to a

feet,
Continue

signal
Add

60 to
inside dial on the

Silent

60
depths

Other
ranges

to a

deeper
SIGNAL INTERPRETATION

Because

tremely

it can

move

you

deep lake,

gradually

away

the

bottom

move around

reaches zero. If the

the water is 60 feet

further,

will start around

whatever

get

Sixty

120

to

greater

Eagle

figure

the correct

1 is calibrated from

feet to

help you

than 60 feet.

models have dual

that allow

deeper

scale when

than 60

your Eagle

sensitive and

give you

feet.

an accurate

from

shore on

signal

depth

deep.

and the

again.

it shows to

depth.

Model

Eagle

to

you

change

you go

is both ex-

powerful,

the

of

bottom

The

read

pic-

ture of the kind of bottom over

which
bottom of firm

shell,

bright, fairly
are

traveling

and the

means

a soft mud bottom. A

absorbs the

turns a weak

simply

a

get

A level

rocks returns the usual

signal

both above and below it.

caused

the sound waves travel.

that

go straight down,

and come back

rectly,
above the level of the bottom.

But the sound waves that hit

boat is

your

or hard

signal

that

you

sound waves and re-

turn

up

bottom

good

bottom with scattered

—

plus secondary

the different

by

passing.

sand,

gravel,

returns a

clay

wide

signal.

over such a bottom

weakens,

have moved over

soft bottom

In

signal.

the

this

sensitivity

reading.

bottom

distances

Those

hit a

cor-

of the rock

that the

indicate,

top

A

If

you

it

case,

signals

This is

rock,

a

rock toward the outer

cone of sound waves and

flected back to the transducer

travel further.

60

their

signals appear

tottom

signal.

A smooth bottom of solid rock
returns a

Broken rock of various sizes
sends back an even wider
with occasional flashes above

and below

bottom, though

aren't so
turned

smooth

Big

bottom send back

distinct as the ones re-

by

botto,m.

rocks or

the level of a smooth

distance
height.

proach
you

climb
side

A

steep slope

nal,

the

underwater cliff
widest. The sure

drop-off

the

wide

to

width,
or

deeper

depending

If

you

a

post

will

often see the

then descend the other

up,

as

you

the

steeper

signal

is the sudden

regular depth signal

then back to the usual

one,

but either more shallow

as the boat moves

Brush will return
varying heights

tom

signal.

with the

bottom, although they

return weaker
brush or tree limbs. In

weeds don't

lakes,
more

is

than 12 or 15 feet

cause of the lack of

Weeds make a

pale signals

of the

edge

are re-

Consequently,

below the

wide,

bright signal.

one,

the level of the true

these

signals

scattered rocks on a

stumps

or a

continue.

on a smooth

signals

bottom,

on their

watch as

tree, however,

signal

above

you ap-

returns a wide

the

returned

being

proof

wider,

from

with

a

high

the

of a

change

to a

past.

flashes of

above the bot-

Weeds also tie in

signals

than

most

in water

grow

deep

sunlight.

be-

great many thin,

on the dial.

the

sig-

of

DETECTING A SMOOTH BOTTOM

Gravel or Hard

14

Fig.

Clay

The

nicest bottoms

to

survey

EAGLE

return a

signal,

either above

with

your

are those that

clear, bright

with no

spikes

or below

it from scattered rocks.

This is the
tom

signal

read and fish at

depth

plainly
Nothing
gratifying

a

big

largemouth
clean

eyes
sandbar

these two
like and that
to fish

bumping

It is

tiple signals
dial from

this

type.

over water 20
deep,

turn

get

signals

40 feet.

easiest bot-

of all

to

above it show

on the dial.

any

is more

than to find

school of

bass over

gravel

over a smooth

for

up

or wall-

—

places

popular

the

by

technique.

to

easy

on the

bottoms of

If

you

example,

the

gain you'll

are

easy

bottom-

get

are

feet

at 20 and

up

that

fish

mul-

and

9

10

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