Lowrance LRG-1510C User manual

Printed in U.S.A. 988-0055-08
INSTALLATIONANDOPERATION MANUAL
MODEL LRG-1510C
GRAYLINE® RECORDER
•LOWRANCE ELECTRONICS,INC.
12000 F. SKELLY DR..TULSA. OKLA. 74128
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

NOTICE
Periodically wash the Transducer Face withsoapand watertore-
move
any
oilfilm that
maycollect Oilanddirtonthefacewillreduce
sensitivity ormayevenprevent
sounding.
GOTA PROBLEM? LETUS HELP!
Ityou
havea
problemwith your
sonar unit,pleasegive usachanceto
help before sending it in for repair.
Assistance canoften beextended bytelephoneor letter. Write orcall
oneofourAuthorized ServiceCentersortheLowrance
Electronics, Inc.,
CustomerService Department in Tulsa,OK.(Toll-free 1-800-331-3889).
Pleasedetailthe problemyouare experiencing.OurService
Depart-
mentmay beabletosave
you
theinconvenienceofreturningyour unit.
Ifitisdeterminedthat
yourunitmust bereturned,full shippinginstruc-
tionswill be provided.
SCHEMATIC DIAGRAM AND PARTS LIST
Shouldyoudesire aSchematic Diagram and PartslistforyourLow-
ranceTRUELINE RECORDER,send$1.00 toPARTS
LIST, Lowrance
Electronics, Inc.,12000 EastSkellyDrive,Tulsa,
Oklahoma74128.Be
sure and give us the Model Numberand Serial Numberof your
SONAR INSTRUMENT
25
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

SPECIFICATIONS— LRG-1510C
DepthRanges
Operating Frequency:
Pulse Length: (durationofpulse):
Operating Voltage:Minimum .
Maximum.
Operating Current
Output Power:
Weight
Dimension: WithGimbal Mount
Width 121/4'
Height
Depth 51/4"
INDEX
WhatIt Is .
HowItWorks.
WhatItTellsYou
Installation
Operation
Scale
Sensitivity
Suppression
PaperSpeed
GRAYLINE®©
HowTo Read Graphs
PaperLoading
Stylus Replacement
Stylus BeltReplacement
Maintenance
Do's and Don'ts
Trouble Shooting
Specifications
p
Howto Obtain Service
2
3
4
6
7
7
7
8
8
9
10
13
19
20
22
23
23
24
25
24 1
0- 30 feet
0- 60 feet
0-120 feet
0-360 feet
192 kHz(192,000 cyclesper
second); accuracy iswithin
0.6percent
its.
volts DC
to 1.8amps depending on
printing density
and output
power.
900 watts typicalpeak-to-peak
(112watts RMS)
8.5 lb. (3.9 Kg)
InstrumentOnly
Width 9½"
Height 7½"
Depth 5¼"
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

WHAT ITis DOSECTION
Sonar"isanabbreviation meaning soundnavigationand
ranging." Itwas
developed asameansoftrackingenemy submarinesduring
WorldWarII.
Sound — when
transmitted throughwater
—travelsatapproximately 4800
feetpersecond as compared to1100through air.
SOUND TRAVELS MORETHAN 4TIMES
_____
FASTER IN WATERASIT DOES IN AIR
- )DDDflflDDflDflfl))flflflfl))I
4800 FEET PER SECOND IN WATER
Insimple terms, anelectrical impulse isconvertedintoasoundwave and
transmitted intothewater.Whenthe wavestrikesanobstacle, itrebounds.
Since thespeed ofsound inwaterisknown —and constant
—thetime
betweenthetransmittedsignal andthereceivedechocanbemeasuredand
thedistancetotheobstacledetermined. Anelectronic sonarunitcanboth
sendandreceive thesound waves, aswellastime, measure, and record
them.
PRINCIPLE OFSONAR
SIGNAL
TRANSMITTED I
ANDRECEIvED
L (((((((N
Fig.2 SIGNALSENT BY LOCATOR BOUNCES BACKFROM
TARGEtTIMELAPSE INDICATES DISTANCE TOTARGET
TheLowrance ModelLRG-1510C
graph recorderisa compact unit specif
i-
callydesigned forsportfishermen. Ithas900watts typical peak-to-peak
power,(112
wattsRMS) features
easy
toread
straight line recordings,hasa
gray line"capability, and provides easy-to-read graphs withsuchclarity
thateven asingle fish hovering just nine inches offthebottom is easily
identified.
Full control of the systemis at your finger tips to meet thechanging
demands ofvarying bottom conditions, waterdepth and boat speed. You
can selectthe unit's sensitivity setting, suppression level, depth range,
paper speed, andthedegree of grayline"used toenhance
the recorded
information. Thepatented Lowrancevariablesuppression system not
only
filtersoutfalsesignalswithout
distorting therealones, butissynchronized
withthe
gray
linefunctiontoprovide clear
signalsunderallconditions. The
permanent recordofwhat your
sonarhas"seen"
isrolledand storedinside
the case.
2
Do carry asparefuse, sty!us belt, and rollofpaper.
Do usethetape
fromanew rollorpaper toattachittothetake-up spool.
Do usethe
empty
cardboardcorefrom
thelast rollofpaper onthe
take-up
post.
Docarry apencil to make notes onthe paper.
Dokeep the recorded graphs
forfuturereference.
Docleanthe stylus beltandwheelswith alcohol afterevery five rolls of
paper.
DON'TSECTION
DON'T OPEN THE CASE WHEN THE UNITISON.
Don't
pull theplaten assembly downwhenthestylus is atthefront,
Don'tstore anyobjectsinside the caseorbehind the viewing
door.
Don't
forgetto tape thepapertothetake-up
core.
Don'trotatethe stylus beltup.
Don'tuse oilycloths, strongsolvents orabrasive cleansers.
TROUBLESHOOTING
SYMPTOM WHATTO DO
B. On/Off switch is "ON", have
zeromark, butnoechoes orbot-
tomsignals
A. Check fuse;check connections
at battery;tighten power cord
connector
D. Recordermarksare faintordim D, Cleanviewing door;replace the
stylus
E. Bendthe
stylusslightly
toreduce
pressureon paper.
A. On/Offswitch is "ON", but the
stylus and paper don'tmove
C. Theunit isON, but paper does
notmove
B. Be sure the transducer is plug-
ged into the unitand thetrans-
ducerisincontactwiththewater
C. Tape Paper to cardboard spoo1
ontake-up post
E. Recordedmarksareveryheavy;
paperistornby stylus
23
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

MAINTENANCE
NOTE: Thestylus may bedamaged if itisin frontofthe platenwhenthe
platenassemblyispulleddown.A/ways movethe stylustothebacksideof
the
platenwhenchangingthe paperrolls.Rememberto movethebeltdown
to remove stylus.
Black carbon dust is createdduring the recording process. Use a soft,
oil-freeragtocleanthe
viewingdoorand metalplatenbehindthepaper.
Low
pressurecompressed
airmaybeusedtoblowdustoutofthecaseandaway
from movingparts/fthe airisdry and freeofoil.
Aftereveryfive rolls of paper,the stylusbelt andthe wheels it rides on
should bewiped clean with asoftrag moistened with alcohol to remove
carbon dust. Strong solvents orabrasive cleaners shouldnotbe used.
Allmechanicalconnections
should bechecked periodicallytobesure
they
haven't worked loose.
DO NOTappy anytypeoflubricant tothe motors or geartrains.
DO NOTwashthe unitwithrunning water. Wiping itwithadamp clothto
remove salt accumulations, dust, or road grime isall that's necessary.
HIGHVOLTAGEis
presentinthetransmittersection whentheunitisON. No
attempt
shouldbemadebyany
unauthorized persontomodifyorrepairthe
electronic section.
Corrosion mayoccur atthe power plug, in thefuseholderor power cord
splices, oratthebattery connections.Allelectrical connections should be
checked periodicallyand cleaned as necessary with400gritsandpaper.
Thefaceofthetransducer, ifmounted onthetransom should bewashed
periodically
withmildsoapywatertoremove
any
accumulatedroad
grimeor
oily
film. Thisisessentialtohavegoodcontactbetweenthetransducer and
thewater.
Periodically,
therubber roller onthe paper driveshould be cleanedwitha
clothdampened with
alcohol,toimprovethefrictiononthedriveshaft. (See
page 16, Figure29).
HOW IT WORKS
When the unit is turned on, an electronically regulated motor drivesa
lightweightbeltlocatedatthe rightedgeofthe recording paper.
The
marking
stylusisattachedtothisbelt.Whenthe stylusisatthe top
ofthepaper, the
transmitter istriggeredandasmall markismadeatthe
top
ofthe
paper.
This
iscalledthezeromark, and represents thesurface ofthewater.
Thestyluscontinues to movedownthe
edge
ofthepaper whilethe
sound
pulseis traveling through the water, and whenan echo isdetected, the
stylusmakes another mark onthepaper.The depth ofthe object
which
• ; reflectedtheechocanbereadinfeet
bycomparing itslocationonthe paper
to thedepth scale on theleftsideoftheviewing area.
Avariablespeedmotordrivesthe
papergraph. (Thepaper
istreatedsothat
the stylus will burn it to leave apermanent, black mark.) During one
revolutionofthe
stylus belt,averynarrowmarkwillbemadebytheflexible
stylus, butthe paper will moveasmall amountbefore thenextrevolution.
Each markwillblendintotheone
before,sothata
composite "picture"
ofthe
targetwill bemade, one tiny mark at atime.
Fieh: 17 ft.
Depth: 35 ft.
TRULINERECORDER BOTHSEND AND RECEIVES SIGNALS. S.
RECEIVED SIGNALSAREINDICATED ONGRAPH PAPER.
Fig. 3
Fig. 4
DRIVE
BELT
STYLUS
PULLEY
—PAPER
TRAVEL
C
22
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

WHAT IT TELLS YOU
Small boat sonar systems are routinely used to measure water depth,
examine bottom contours, and locatefish — but the capability of the
LRG-1S1OC goesfarbeyond theordinary.Clues tothe composition ofthe
bottomaregiven
—schoolsofbaitfishareeasily
distinguishedfrom solitary
game fish — thereis a continuous display of information about bottom
contours, submergedshipwrecks —fishasclosetogether assixincheswill
beshown separately — concentrationsofalgae, moss orplankton canbe
identified— attrolling speeds individualfishare commonlyrecordedwitha
characteristic 'arched" signature which distinguishes them fromtheirsur-
roundings — layers ofwaterwith differenttemperatures canbedetected
undergood
conditions, andverticalmovementoffish, (upordown), canbe
shown.
Fig.5 Fig.38
LOWRANCE STRAIGHTLINERECORDER
Thisisa
sampleofthe
graph printoutby
aLowrance
Straight
LineRecorder.
Aand 0 indicate bottom depths of 16 feet and 46 feet respectively. B
represents anecho(asecond
signal) causedfroma veryhard orreflective
bottom surfacewhich
causesthesonar
signaltobouncebacktothewater's
surface, returntothebottom and reflectbacktothereceiver Therefore,the
timeforasonarsignaltotraveltothe bottomand backtothesurface has
doubled. Ifthetruebottom readingis16feet,the
echowillappear at32feet.
Ifthetruedepth wereten feet, then theechowould occur20feet. Cand F
indicatelargefish.Thethermocline isindicatedat28feet
(G)
withschools of
baitfish scattered from4feetto20feet. Itisalso possible toseesmalland
medium size fish by their arched"
signatures.Thedarklineacross the top
ofthe papergraph (H)indicates "zero"orthewater'ssurface.
4. Grasp the beltatthe stylus holderwiththethumb and forefinger
and
move itgently tothe leftwhile pushingthebeltoffthewheels withthe
other
forefinger. (SeeFigure 38.)
5. Positionthenewbeltonthewheelsbyreversingtheprocedureusedto
removetheoldone. BESUREthefingers ofthenewstylus
arepointed
UP.
6. Closethefrontofthe case. Latch both catches on thetopoftheunit.
0—
10 —
20 —
30 —
60
1
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

The30'scale
givesyou
anewdimensioninresolutionanddetail. (Seechart
STYLUS BELT REPLACEMENT
— CAUTION —
High voltage
ispresent in theelectronicsection when theunitis
turnedon.
1. TURN THE UNIT OFF.
2. Releaseboth
catchesonthetop ofthecase. Pulloutanddownonthe
top
ofthecasefronttoexpose the stylus belt.
3. Thestylus beltrides overtwowheelslocated atthe right edge ofthe
platenassembly.RefertoFigure4onpage3.Move thefrontofthe belt
DOWN to positionthestylusatthe centerofthe platen.
samples
below).TheLRG-1S100doesthiswithout
increasingmotor speed,
therefore, increasinglife ofstylusbelt, stylus,bearingsand themotoritself.
Fig.6
TheLRG-1510Cisa
complete sonar.Itscontrols aresimple enough
forthe
occasional fisherman, andflexibleenough tosatisfy the most demanding
pro.
We
encourageyou
tostudy theremainderof
thisbooklettoget themost
fromyourinvestment and toboost your boating and fishing pleasure.
Fig. 7
Fig.35
Fig. 37
p
5'
— 10'
p'7
.r'" BOTTOM
-Is — 25'
THISISWHATAREPRESENTATIVE
AREAWOULDLOOKLIKEONTHE0-30' SCALE.
'—30'
7. Afterinstalling,ifthestyluswon'tprintallthe
waydownthe paper,(See
Figure 37) bend the right leg down so that more pressure is exerted
againstthestainlesssteelplate. Ifitstill doesnot print allthe way,bend
theleftlegdownmore (butnotso farthat it digs intothe paper).
8. Closethefrontofthecase. Latch both catches onthe
topofthecase.
— 0'
THISISWHAT THESAME AREA (SEE UPPER CHART)
WOULDLOOK LIKE ONTHE
0-60' SCALE.
BESUREtoinsertthetwo rubber grommets
ongimbal bracket. Thelarger side (larger
diameter) ofgrommet goes on inside of
gimbal bracket sothatit is sandwiched
between gimbal bracket and sonar instru-
ment (see drawings). Thegrommets provide
friction to holdthe unitatthedesired angle. ____________________
20 5
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

INSTALLATION
MOUNTING
Any
convenientareaissuitableformounting, providing theunitcanbetilted
forthebest
viewingangle.Thereareeightmountingholesinthebaseofthe
gimbal bracket for wood screws or thru-bolts. If necessary, a wooden
stiffenercanbeused on the backside ofthinfiberglass panels.
If
thedesired mountinglocation iscloserthan18"toa
magneticcompass, a
trialrun shouldbemade, with theunit/n
operation, tobesurethe
compass
readings
are notaffected.
POWERCONNECTIONS
12voltDC power forthedepthsounder issupplied from theboat's 12volt
electrical system. Power
may
bepickedupatanaccessory orpower buss,
butifyouhaveproblemswithelectrical interference (indicated by
extrane-
ous
flashesonthe
dial)itcanbeminimizedbyconnecting powerdirectly
to
the battery.
Ifalongerpowercableisrequired,use
ordinary
#18lamp cordavailable at
anyhardware store. Splices should besoldered. Ifthis can'tbedone, use
crimp-type connectors. Simple twistingofsplicesmayresult in intermittent
powerconnections which can cause interference. Tape all splices with
plastic electrical tape.
IMPORTANT NOTICE
When installingthe
powercable,
makecertainthatthein-linefuse
supplied
withtheunitisattached tothecenter
conductorofthe
power
cableasclose
tothe
power
sourceas
possible. Thiswillprotect
boththeunitandthe
power
cableincaseeitherisevershorted.Aconnector issupplied toattach the
fuseto the power cable.
Thepositive conducterin thepower cableisthecenterconductor. The
unitisprotected fromaccidental polarity reversals and nodamage will
resultifbatteryconnections are wrong.(However, theunitwillnot
work)
STYLUS REPLACEMENT
— CAUTION —
High voltage ispresentin theelectronic section when theunitis
turned on.
1. TURN THEUNIT OFF.
2. Releasebothcatchesonthe
top
ofthecase.Pull
out
anddownonthe
top
ofthecasefronttoexpose thestylusbelt. (See Figure 34.)
3. Thestylusbelt rides overtwowheels located atthe
platenassembly. MovethefrontofthebeltDOWNto
atthecenterofthe platen.
4. Holdthestylus belt
stationary withone finger,and removetheold
stylus
bystarting atits left edge
andmoving itoutfromunderthetabsonthe
stylus holder.
5. Before installingthenewstylus, besureitisbent
properly bycomparing
itto Figure 35.
6. RefertoFigure36tobesurethe
newstylusispositionedcorrectly under
thetabson
theholder.Besureitmoves
freely
inthetwoslots.If
not, bend
thestylusaway fromtheedgeitisrubbingonuntil itdoesmove freely.
19
right edgeofthe
position
the
stylus
Ground
Fig.8 (Negative)
Fig.34
(Positive)
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

10. Push the platen assembly back to its operating position. Be sure it
engages
the catch insidethetop ofthe case. (SeeFigure 32.)
11. Close thefrontofthecase.
Latch both catches onthetopofthe case. (SeeFigure 33.)
Fig. 33
Fig.32
Turnthe uniton.
Move theChart
Speed knob fully
clockwise. Watch
the paper long
enough
to be
sure it is moving
smoothly and
evenlyacross the
platen. Ifthe
paper flutters or
begins
to run
up-hill', repeat
Step8.
OPERATION
SCALEKNOB — used to
select recording depth. There
are fourpositions:
30feet
60feet
120 feet
360 feet
Fig.9
ON/OFFANDSENSITIVITY KNOB— RotatetheOn/Offknobclockwise
toturntheuniton.The
Sensivityknobworksmuchlikethe
volume
controlon
a radio,that is, weaker signalswillbedetected with highersettings ofthe
knob. When cruising, orat othertimeswhenjustsimple bottom-contour
information isdesired, the Sensitivitysetting canbelow. Indeepwateror
oversoft, muddy bottoms, (which produce weakechoes), thesetting will
haveto be higher.
When
highSensitivity settingsare used,asecond bottomechowill appear
Thisisnormaland iscausedbythereturning signalreflectingoffthesurface
ofthewater, making a secondtriptothe bottom and back.
Whendetailed informationaboutbrush piles, individual fish orthe thermo-
dineisdesired, the
Sensitivityknob should besetatabout3/4point. Refer
totheillustration belowtoseewhateffecttheSensitivitysetting hasonthe
recorded information.
C---
I fl--- 12.
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

Fig.10 Fig.ii
SENSITIVITY: ¾SETTING
A. TREE
B. THERMOCLINE
C. BAITFISH
SCHOOL
D. GAME FISH
(NOTE:ELONGATED
ARCHED SIGNATURES DUETO
VERY SLOW BOAT
SPEED)
Recording individual fish with an arched" signature can usually be ac-
complished attrolling speed withthe Sensitivity knobatthe 3/4point, or
higher. Referto the section Arched Signatures," on page 10 for more
information aboutthisimportant function ofyour recorder,
SUPPRESSION KNOB — Is used to reduce interference from noise.
Noise, in electronic terms,
isanyundesired signal. Itcanbecaused byan
electricalsource, (suchasthe
engine's ignitionsystem), orbyairbubblesin
disturbed
waterwhichiscalled cavitation noise. In both cases, the noise
could produce unwanted marks on the paper. (Seepage 11, Figure 18.)
Fortunately,noise pulsesare relatively
shortintime
compared torealsonar
signals. Advancing theSuppression knobwillcausethesystem toreject
theseunwanted, shortpulses without
reducing thesensitivity in anyway.
Thispatenteddesign isexclusivewithLowrance. However,withhighsup-
pression settings, the graph record becomes coarse and the abilityto
separate fish fromthe bottom or fromotherfish will bedecreased. (See
page12, Figure22.)
Therefore,thelowerthe
suppressionselling
thebetter.
Advance the knob sellingonly asfaras necessary toremovethe erratic,
unwanted noise marks. Mostof the time at low or trolling speeds, no
suppression will beneeded.
PAPERSPEED KNOB—Controlsthespeedofthechart
paper.For good
detailwhen
trolling and lookingforfish,orwhen runningathigh speed,turn
the paper speed knob up at leasthalf-way.Forbestdetail,turn it up to
maximum.Thiswillshow properfish archesatlow
speeds
andkeeps high
speed information frombeing compressed. (See 'HowtoRead Graphs.")
Whencharting onthe360'scale indeep
water,thepaperspeedshouldbe
8. Drawthe end of the paper across the face ofthe platen, around the
friction roller,overthe take-up core, and tape itsquarely tothetake-up
core. (SeeFigure 30.)(Hint: small strips oftape maybestoredinside
housing.) Fig.30
.t!!_!Tflr7%1T.WV_ "1
4- -
I—
SENSITIVITY: /4SETTING
ONLY THE BOTTOM SIGNAL
ISDISPLAYED. ALLFISH
SIGNALSARELOST.
9. Holdthe
take-upspool,andturnthe supplyspool
clockwisetoput asmall
amount oftension onthe paper.It should besnugagainsttheplaten.
(See Figure 31.)
Fig.31
17
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

• b
L. -
BOULDERS/LARGEROCKS Fig. 12
GRAYLINE OFF"
r:
I
I'-..'
',,-, /'
r is.
- —C
GRAYLINE®: 'OFF'
A. FISH
B. TREES
C. FISH IN TREES
D. BAIT FISH SCHOOL
6. Remoovethe
emptysupplycorefromthe rightSideiflthesamemanner.
Alignthetwonotchesinthecorewiththetabsonthe
lowertake-upspool.
(See Fig. 28) Push thepaper retainerknobin androtateituntilitlocks
into place.
NOTE: Both LPG-602and LPG-603chartpaper canbeused inthisunit.
However, to use the paper core from the LPG-602 chart paperon the
take-upside ofthechart drive, notches mustbecutintothecore. These
notches should be 1/4" wide by 3/16" deep on both sidesof the core.
LPG-603 chart papercomes with the notches sonomodification isneces-
sary
when
usingthe papercoreonthe take-up
sideofthe
paper
drive. Both
LPG-602andLPG-603chart
paper
canbeused onthe
supply
sideofthe
chartdrivewithoutmodification.
turneddowntonomorethan half-way forthebestrecord. Ifgaps appear
between stylusstrikes, thepaperisrunning toofast.Thepaperspeed may
alsobe turned downto conserve paper whennotlooking forfish orcon-
cerned withfinedetail.
r
p.' ,/'
BOULDERS/LARGEROCKS Ag. 13
GRAYLINP: "ON"
7. Putafresh rollofpaper in positiononthecentering posts ofthe paper
spool end capsonthesupply side (right) ofthe platen assembly.The
papermust spooloffthebottomoftheroll. (SeeFigure 21.)
w Fig. 14 GRAVLINP: "ON"
A. FISH
B. TREES
C. FISH INTREES
D. BAIT FISH SCHOOL
Hg.29 Arrowindicatesfriction roller
GRAYLINE®ON/OFFKNOB—TheGRAYLINE®function canbeused to
outlinethebottomcontourwhichmightotherwise behidden beneathtrees
and brush; itcanalso give clues tothecomposition ofthe bottom. Ahard
bottomreturnsa
veryStrongsignalcausinga wide
grayline.Asoft, muddy
orweedy bottomreturnsaweaker
signalwhichisemphasizedwithanarrow
gray line. Do not advancethe
controltoo farorit
willgraylineonfish,trees,
etc. Inwaterless
than 30', justclick the knob "on" — do notadvance the
control knob.
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

HOW TO READ GRAPHS 5. To removethefulltake-up roll, pushinandrotatetheleftpaper retainer
"ARCHED
SIGNATURES" —Aremarkableadvantage oftheLRG-15100
isthat itcan record individual fish with acharacteristic arched mark that
separates them from theirstationary surroundings. Thereason forthisis
shown below.Thedistance to
afish when it moves intothe sonar's coneof
sound is shown as 'A" in thedrawing. When
thefish has moved tothecenterofthe cone,
thedistancetoitwill beshorter, (line "B"),
andas itmoves outofthe cone, thedistance
will increase again as shown in line "C".
Ifapartial arch occursmost ofthe
timeon yourunit(themark curves
up butdoes notcurvebackdown), it
is because thetransducer is not
aimed straight down.
Sharp, well-defined signatures will occur mostoften whenthe Sensitivity
knob isset atthe3/4point orhigher.(See(C), Figure17.)Remember,too,
thattheremustbesomemovement between thefish and boattodevelop
thearchedmark.
knobuntil itsnapsout. (See Figure 26.)The roll can now be easily
removed fromthepaperspool end caps. (SeeFigure 27.)
60 —
THERMOCLINES
— The temperature of water in the lake is seldom
constant from
top
tobottom.Layers of
differenttemperatures form, andthe
junction
ofawarmandcoollayer ofwateriscalled athermocline.The
depth
andthickness ofthethermoclinecanvary withtheseasonortimeofday. In
deep lakestheremay
betwoormore,atdifferentdepths. Thermoclines are
important tothefisherman because theyare areas whichfishare active.
Many
timesbaitfishwill be abovethethermocline whilelargergame fish
suspend justbelow it. (See (G), Figure 17.)
YourLowranceModelLRG-1510Ccandetectthisinvisible layer
inthe
water,
butthe Sensitivity knobwill probably have to be set atthe3/4 point, or
higher.
Fig.16
Fig.17
0—
20 —
30 —
40 —
50 —
1
Fig.27
15
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

3. Movethestylus beltDOWN, (ontheright side oftheviewingarea), to
position
the
marking stylusontheback sideofthe
platen.NEVERmove
thebeltup— thestylusmay be damaged.
SPECIALNOTE: Thestylus maybe damaged ifthe platen assembly is
pulled
downunlessthe
stylus
hasbeenmovedtothebacksideofthe
platen.
4. Pulloutanddownonthetabatthe
top,centerofthe platen assemblyto
exposethe paper spools. (SeeFigure 25.)
Fig.25
High Speed (46 M.P.H.)
SUPPRESSION: OFF
SENSITIVITY: ON— 1/2POSITION
NOTE POOR RECORD CAUSED
BYNOTUSING SUPPRESSION
WHENAT HIGH SPEED.
Fig.18
A. JIGGING A1¾oz. HOPKINS
'SPOON IN SUBMERGED TREE.
B. FISH SIGNALS
(BOATDRIFTING
VERY SLOWLY OVER FISH).
C. BAITFISH
High Speed (46M.P.H.)
SUPPRESSION: ON— ADEQUATESETTING
SENSITIVITY: ON— 1/2 POSITION
14
GRAYLINE®: 'OFF"
A. FISH ON ORNEARBOTTOM
Fig. 20
.:y ...:wfl®
M¼&VM I
IA
GRAYLINE®: "ON"
A. FISHONORNEARBOTTOM
flg.1g I .
SCALE:0 TO60 FEET
PAPER SPEED: SLOW
SUPPRESSION: OFF
DEPTHS: RECORDED FROM 18
INCHES TO7'/2 FEET
'1
PDF compression, OCR, web-optimization with CVISION's PdfCompressor

tr\ -. 1
/\t' -
"N\2_ —
P - 1. TURNTHEUNIT OFF
.1
1
/
____ PAPER LOADING
Fig.21
— CAUTION —
High voltageis present intheelectronic section whentheunitis
turned on.
A. FISH DRIFTING UNDER BOAT.
FISH MOVED FROM 13½FEET
TO21 FEETTO12 FEETWHILE
DRIFTING/SWIMMING WITHIN
THECONE OFSOUND.
B. JIGGINGALEAD-HEADLURE
OFF 8011DM.
SCALE: 0TO60FEET
GRAYLINE! "ON"
A. AFISH SUSPENDED UNDER BOAT
B. FISH SWIMMING UPTOWARDS BOAT
C. SCHOOL OFBAITFISH
D. SURFACE CLUTTER
SCALE:0TO60 FEET
GRAYLINE®:"OFF"
2. Releasebothcatchesonthe
top
ofthecase. Pulloutanddownonthe
top
ofthecasefronttoexpose theplaten assembly.(See Figure 24.)
Fig.23
C
C
I
Fig.22
SUPPRESSIONz TOO HIGH SUPPRESSION: PROPER SElliNG
(NOTE
THATRECORDER SIGNALSFROM (NOTE DISTINCT INDIVIDUAL
SCHOOLS OFBAIT FISH AREELON- SCHOOLS OFBAITFISH.)
GATED AND RUNTOGETHER WITHTHE
BOTTOM.)
END-OF-PAPER MARKER— Thegraph paper used in the LRG-1510C
hasaredlineprinted atthebottomof
thepapertosignifywhenthereisonly
2to3feetbeforetheend ofthe paper(SeeFigure23 on Page 13.)
Fig.24
13
PDF compression, OCR, web-optimization with CVISION's PdfCompressor