Eagle SILENT 101 INSTALLATION INSTRUCTIONS

sound ends at the bottom. But

an echo is also returned from

any object

ducer and the bottom.

As

you

a

deep

will

dial until it dial is

100

feet,

deep.

bottom

again.

shows to 100 to

depth.

dual

change you go deeper

SIGNAL INTERPRETATION Because

tremely

it can

ture of the kind of bottom over

which bottom shell,

bright, are

traveling

and the

means that

between the trans-

move

away

the bottom

lake,

gradually

calibrated

Continue

signal

Add whatever

Other

ranges

to a

move around the

reaches zero. If the

water is 100 feet

the

further,

will start around

get

Eagle

that

deeper

than 100 feet.

your Eagle

sensitive and

give you

your

of firm

or hard

fairly

signal

an accurate

boat is

sand, gravel,

clay

wide

over such a

weakens,

you

from shore on

signal

to a

figure

the

models have

allow

scale when

depth

and the

correct

you

of

it

to

is both ex-

powerful,

pic-

passing.

returns

signal.

have moved over

A

a

If

you

bottom

it

a soft mud bottom. A soft bottom

absorbs the sound waves

a weak

turns

simply

a

good

get

turn

bottom

signal.

the

up

reading.

A level bottom with scattered

rocks returns signal — plus

both above and caused

the usual bottom

secondary signals

below it. This is

the different distances

by

the sound waves travel. Those

that

go straight

come back

and

rectly,

that the

above the level of the bottom.

But the sound

down,

indicate, top

waves that hit a

and re-

In this

sensitivity

hit a

cor-

case,

rock,

of the rock

to

is

rock toward the outer cone of sound waves and are re-

flected back to the

travel further.

their

signals appear

bottom

signal.

A smooth bottom returns a

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

wide, bright signal.

transducer

Consequently,

below

of solid rock

edge

of the

the

one,

and below the level of the true

bottom, though

these

signa]s

aren't so distinct as the ones re-

turned

smooth bottom.

rocks or

Big

bottom send back

the level of a smooth

distance height.

proach a post

will often see the

you

climb side as

A

steep slope

the

nal, the

signal

underwater cliii widest. The sure

drop-off

the

regular depth signal

wide width,

or

deeper

Brush will varying heights

tom with

return weaker

scattered rocks on a

by

stumps

depending

If

you

or a

then descend the other

up,

continue.

you

on a smooth

signals

bottom,

on their

watch as

tree,

you ap-

however,

signal

returns a wide

the

steeper

wider,

returned from a

the

being

of a

is the sudden

then back.to the

one,

proof

change

to a

but either more shallow

as the boat moves

return flashes of

above the bot-

signal.

the

Weeds also tie in

bottom, although they

signals

than

above

the

sig-

with

high

of

usual

past.

brush or tree limbs. In most

lakes, more than 12 or 15 feet

cause of the lack of

Weeds make a

pale signals

weeds don't

great many thin,

on the

in water

grow

deep

sunlight.

dial.

be-

DETECTING

0

Gravel or

I

14

Ag.

Hard

Ciay

A

SMOOTH BOTTOM

The nicest bottoms

to

survey

EAGLE

return

signal,

either

it from scattered

This is the easiest tom read and fish at

depth

plainly

Nothing

gratifying

a

big

largemouth clean

eyes

sandbar

these two like and that are

to fish bumping technique.

It is

tiple signals

with

your

are those that

a

clear,

of all to

is

more

bright

spikes

any

with no

above or below

signal

above it show

on the dial.

than to find

school of

bass over

gravel

over a smooth

or wall-

—

places

popular

the bottom-

by

to

easy

on the

get

rocks.

that

fish

easy

mul-

dial from bottoms of this

over water 20 feet

deep,

turn

get signals

40 feet.

type.

for

the

up

If

example,

you

are

gain you'll

at 20 and

bot-

up

and

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WEAK SIGNAL

The

trol on might

sensitivity

your

be

compared

the volume on a

'ibm the

knob to the you

ceiver

it to

reduce it.

is

provided

can use over both shallow water

should

the

bright

shows on the

gardless you

have tom

will

in the

the

bottom. This

is

shown in the

ing

sensitivity

increase the

sensitivity;

the left and

This

your

deep

always

so that a

gain

bottom

of

depth.

fail to do

a

only

signal fail to show

the dial

water between

transducer and

above

—

are there but aren't shown on

dial because is

set too low.

con-

EAGLE

radio.

and

right

re-

you

feature

so that

EAGLE

and

adjust

signal

dial,

If

so and

faint bot-

fish

condition

draw-

the

fish

they

the

gain

INDICATES GAIN

to

turn

you

re-

the

TOO LOW

Fig.

15

12

Fig.

Fish, 17 ft.

Depth,

constant

on a disc driven governed

lighted every

ter

reference is used

measure cator

on. Even

flashes,

the human nearly

The bulb

point the

the

by

sound waves to

and ieturned

vater

bottom fire the these

show

—

or

the water.

sound

down into

go

speed

motor.

time

fires. This

point

as a

starting point

depth,

that the

though

it

happens

eye

constant

also flashes at the

on

the dial that

Fhe

depth.

length

of time it

return. In

from

between the

echoes are

the exact

number of fish

any

And

Waves from the

the water in a nar-

35 ft.

behind

the dial

an

by

accurately

The bulb is

the transmit-

provides

on the

and

depth

sees it

a visual

dial which

to

as an indi-

sounder is

the neon bulb

so. often

that

as a

light.

indicates

is indicated

point

takes the

reach the bottom

addition,

any object

bulb,

also

depth

because the

echoes

in the

surface and

too. Since

timed,

of

they

fish

any

—

in

transducer

row cone

a matter

location

At a

covers a

mately

15 feet it is

feet, diameter

gardless

angle, they tell, of a few

as well as the

depth

circle that is

one foot in

three feet

is four feet wide. Re-

of

feet,

of 10

feet,

two feet

wide,

depth,

the cone of

within

the fish's

depth.

the cone

approxi-

diameter;

at 20

wide,

the cone

at

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ii

S

to

ing the

fish.

insure that

underwater

Depths greater

detail as

than 100 feet can

also be measured on the For

instance,

from 90 feet to 110

goes will

see the bottom

dial move to the 10-foot

scale.

Thus,

lution, depths

be read

may to the

reading

If in doubt as to

off until scan disc

as the water

the "zero"

past

marlc on the outer

on

the second revo-

of 100 to 200 feet

by adding

on the dial.

depth,

they

signal

stops.

see all

well as

Eagle.

depth

feet, you

on the

signal

100 feet

turn unit

Thrn

unit back on and watch to see if

bottom olution

does,

plus

signal completes

before

you

100 feet. If the

stopping.

are at the

one rev-

If it

depth

signal

shown

PRINCIPLE

)flfl)flflflflflflfl)flfl

Fig.

SIGNAL SENT BY LOCATOR BOUNCES BACK 'FRoM

TARGET. TIME

11

LAPSE INDICATES DISTANCE

travels around the dial

plus

will

200 feet.

times, you shown

HOW TO USE

at the

be

YOUR

EAGLE DEPTH SOUNDER

'rhe word "Sonar" is

ation of

Ranging.

ing

Sound,

World

It

was

War

tracking enemy

Sound travels at

feet

4,800 water as

mately 1,100 through

OF SONAR

second

per

compared

feet

air.

(((((

transmitted

When this wave strikes

it rebounds.

ject,

of sound

known,

the transmitted

received echo

and the

determined.

The

Eagle

mits a

wave (which

as

well

water. At the same

intensity

into the water.

through

time

the

can be measured

distance to the

depth

high frequency

is inaudible to fish

as

humans)

neon

an abbrevi-

Navigation,

developed

II as a means of

submarines.

approximately

through

to

approxi-

second

per

(((N

TO TARGET

Since the

water is

lapse

signal

sounder

through

time, a high

bulb whirls at a

two

depth

and

dur-

an ob-

speed

between

and the

object

trans-

sound

the

HARD

Sand bottom

4.

Fig.

CLAY, SAND, GRAVEL,

16

SHELL

BOTTOMS

Some

fish, including

bass, catfish, walleyes,

and

crappies,

sionally the bottom. Even here

lie

right

the EAGLE will show

them as provided

smooth

gravel. Signals

appear

both above and below

you pass

the bottom is

sand, shell,

on the dial

the clear bottom

nal, just over a

The reason for this

is that the

turning near

cone of sound doesn't

travel signal

the same as

rocky

signal

from a

the center of the

so far as the

that hits a fish

near the outer

the cone. Con-

sequently,

from the

middle shows above

the

fish in the

the bottom while the

signal near

below the

from the fish

the

edge

bottom.

occa-

on

over,

will

sig-

bottom.

re-

fish

edge

signal

shows

or

of

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