Lowrance 1240A User manual

INSTALLATION AND
OPERATION INSTRUCTIONS
1240A
IN-DASH MOUNT SONAR
http://www.lowrance.com

INSTALLATION
MOUNTING
Your1240Aisdesignedforconvenientmountingthedashofyourboat,or
it can be mounted on any flat panel that's at least four inches in diameter.
If the sonar is to located in the vicinity of a magnetic compass, run it in
positiontemporarilytomakecertainitdoesn'taffectthecompassreadings.
Ifthecompassheadingchanges,chooseanalternatelocation.(Note:The
sonar must be running when you make this test.)
Tomountthe1240A,firstmakecertainthereisclearancebehindthedash
inthedesiredlocation.(Seebelowfortheunit'sdimensions.)Also,besure
thereisenoughroomtoconnectpowerandattachthetransducerconnec-
torattherearoftheunit.Atleast51/4"areneededfromthefrontsurface
ofthedashtoclearallconnectorsandwiring. Onceyou'vedecidedonthe
mounting location, mark the spot.
Next,determinewheretomountthecontrol.Selectanareawithsufficient
spaceforthecontroldecalonthefrontandenoughdepthbehindthepanel
for the control. The maximum panel thickness the control will attach to is
5/8".Makecertainthecontrol's cablewillreachthedisplay.Markthespot
for the control.
Usinga33/8"holesaw,drillthedisplaymountinghole.Thedisplay'sbezel
willoverlaptheholeby5/16",hidingminorchippingwhichmayoccurwhen
drilling the hole in fiberglass.

Now drill the hole for the control. Use a 3/8" drill bit.
MAKE CERTAIN THAT ALL HOLES ARE DRILLED PERPENDICULAR
TO THE MOUNTING SURFACE AND NOT AT AN ANGLE.
A "U" bracket is supplied to hold the sonar to the dash. Place it over the
studs on the back of the unit and secure it using the nylon wing nuts
provided. If the "U" bracket is too long, it can be cut to the desired length
with a saw.
Before mounting the control, clean the mounting surface for the control
decal. Remove the paper backing from the decal to expose the adhesive
andplaceitoverthecontrol'smountinglocation.Makecertaintheholesin
the decal and dash are aligned.
Mounting hardware for the control, consisting of two nuts, lockwashers,
andflatwashersaresuppliedinthehardwarepack.First,threadanutonto
theshaft.The amountofthreading depends onthethickness ofthedash.
Placealockwasherandaflatwasherontheshaft.Insertthecontrolinthe
holefromthebacksideofthedashandplaceanotherflatwasherandlock
washerontotheshaft.Threadtheothernuton,butdon'ttightenityet.Place
thelargeknobontotheshaftandtightenthesetscrewenoughtolockitinto
position on the flat side of the shaft. With the switch in the far left "OFF"
position, rotate the control so that the pointer on the knob aligns with the
"OFF"positiononthedecal.Whenit'sproperlypositioned,slidetheknob
off and tighten the nut on the control. About 1 1/2 threads should show
beyond the nut on the front of the dash. Place the foam washer and large
knobovertheshaftandtightentheknob'ssetscrew.Placethesmallknob
onto the shaft, align the setscrew with the flat on the shaft, leave a small
gap between the small knob and the large one and tighten its setscrew.

POWER CONNECTION
12-voltDCpowerforthe1240Aissuppliedfromtheboat's12-voltelectrical
system.Youcanconnectthepowereitherfromanexistingfuseblockthat's
behindthedashordirectlytothebattery.Anin-linefuseholderissupplied
withtheunitincaseafuseisnotavailable. Attachthefuseholderasclose
tothepowersourceaspossible.Thiswillhelpprotectboththeunitandthe
power cable in the event of a short circuit.
Caution! Never connect this unit to power without a fuse!
Thepositivewireisred.Thenegativewireisblackandshouldbeattached
to the negative ground buss or the negative side of the battery.
Thisunitisprotectedfromaccidentalpolarityreversalandnodamagewill
resultifthebatteryconnectionsarewrong.However,theunitwillnotwork
until correct polarity is applied.
OPERATION
To turn the sonar on, rotate the large control knob from the "off" position
toeither40feetor100feet.Thisisathree-positionswitchandcontrolsboth
poweron/offandrangeselect.Toturnthesonaroff,rotatetheswitchback
to the "off" position.
SENSITIVITY CONTROL
(Pull Out for Maximum
Suppression)
RANGE AND POWER
ON/OFF
RANGE SELECT
There are two scales on the 1240A - 0 to 40 feet and 0 to 100 feet. Make
the selection by turning the large knob to the 40 or 100 setting. Depths
greater than 100 feet can also be measured. For instance, as the water
depth goes from 90 to 110 feet, you will see the bottom signal on the dial
move past the "zero" signal to the 10-foot mark. Thus, on the second
revolution,depthsof100to200feetcanbereadbyadding100feettothe
reading on the dial.

Ifyou'reindoubtaboutthedepth,turntheunitoffuntilthescandiscstops.
Turn it back on and watch to see if the bottom signal completes one
revolutionbeforestopping.If it does, thepresentwaterdepth is the depth
shown plus 100 feet. If the signal travels around the dial two times, the
water depth is the depth shown plus 200 feet.
SENSITIVITY
Vary the sensitivity by rotating the small knob. It works similarly to the
volume control on a radio. Turned fully counterclockwise, it's at minimum
and the only signal that will appear on the dial, (unless it's in extremely
shallowwater)willbetheconstantsurfacesignal at "0". Turning the knob
clockwise will increase the receiver sensitivity and weaker echoes from
deeper water shows on the dial.
For example, if you are in 10 feet of water and the sensitivity control is at
minimum, you will see only the "0" signal. As you turn up the sensitivity, a

signalappearsat10feetonthedial.Asit'sturnedupmore,thissignal will
get wider and other smaller signals from fish (if present) appear between
0and10feet.Thebottomsignalgetswiderbecauseyouareseeingmore
bottomarea.Rememberthatthetruedepthisalwaystheshallowestedge
ofthebottomsignal,NOT the middle. Asyouturnthesensitivityup more,
another signal appears at 20 feet on the dial, double the depth of the first
signal. It's caused by the sound waves hitting bottom, bouncing back,
hittingthesurfaceofthewaterandthenbouncingdowntothebottomand
back again. These signals have travelled double the actual depth.
Always set the sensitivity to return a steady bottom signal, regardless of
depth.Toshowfish,adjustthesensitivitytoshowasecondbottomsignal,
when possible.
SUPPRESSION
Usesuppressiontoreduceoreliminatefalseflashesonthedialcausedby
electricalinterferenceorcavitationonthetransducer.Withthesmallknob
pushed in, suppression is at minimum. This is the normal position for
trolling as it gives the highest resolution (ability of the sonar to separate
targetssuchasfishthat are close togetherornearthebottom).To switch
tohighsuppression,pulloutthesmallknob.Youwillfeela"click".Theknob
in the "pulled-out" position gives the best interference rejection which is
usuallyrequiredwhenoperatingatspeed.Becauseofthetypeofsuppres-
sion circuity used by Lowrance, the unit's sensitivity is not affected.
(Sensitivity in a sonar unit is measured by the instrument's ability to read
atdepth plusshow details.)Asmallamountofresolutionwillbelostwhen
engaging suppression. Note that suppression can be engaged by pulling
out on the sensitivity knob at any time.
SPECIFICATIONS
Dimensions.............................. Fits 3 3/8" diameter mounting hole
Maximum outside diameter 4"
Depth behind mounting surface 4 5/8"
Weight: .................................... 23 oz (with control)
Dial .......................................... 0-40 feet; 0-100 feet
Input Voltage ........................... 12 vDC (10.5 to 15 vDC)
Current Drain........................... 200 ma., one echo
Transmitter Frequency ............ 192 kHz
Pulse Repetition Rate .............. 0-60 ft - 60 pps
0-100 ft - 24 pps
Pulse Width ............................. Suppression minimum - 200 us
Suppression maximum - 800 us
Output Power .......................... 150 watts peak to peak (19 watts RMS)

LOWRANCE ELECTRONICS
FULL ONE-YEARWARRANTY
“We", “our”, or “us” refers to LOWRANCE ELECTRONICS, INC., the manufacturer of this
product. “You” or “your” refers to the first person who purchases this product as a con-
sumer item for personal, family, or household use.
We warrant this product against defects or malfunctions in materials and workmanship,
and against failure to conform to this product’s written specifications, all for one year (1)
from the date of original purchase by you. WE MAKE NO OTHER EXPRESSWARRANTY
OR REPRESENTATION OF ANY KIND WHATSOEVER CONCERNINGTHIS PRODUCT.
Your remedies under this warranty will be available so long as you can show in a reason-
able manner that any defect or malfunction in materials or workmanship, or any non-
conformity with the product’s written specifications, occurred within one year from the date
of your original purchase, which must be substantiated by a dated sales receipt or sales
slip. Any such defect, malfunction, or non-conformity which occurs within one year from
your original purchase date will either be repaired without charge or be replaced with a
new product identical or reasonably equivalent to this product, at our option, within a rea-
sonable time after our receipt of the product.If such defect, malfunction, or non-conformity
remains after a reasonable number of attempts to repair by us, you may elect to obtain
without charge a replacement of the product or a refund for the product. THIS REPAIR,
REPLACEMENT, OR REFUND (AS JUST DESCRIBED) IS THE EXCLUSIVE REMEDY
AVAILABLE TOYOU AGAINST US FOR ANY DEFECT, MALFUNCTION, OR NON-CON-
FORMITY CONCERNING THE PRODUCT OR FOR ANY LOSS OR DAMAGE RESULT-
ING FROM ANY OTHER CAUSE WHATSOEVER. WE WILL NOT UNDER ANY CIR-
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DENTAL, OR OTHER INDIRECT DAMAGE OF ANY KIND.
Some states do not allow the exclusion or limitation of incidental or consequential dam-
ages, so the above limitations or exclusions may not apply to you.
This warranty does NOT apply in the following circumstances: (1) when the product has
been serviced or repaired by anyone other than us, (2) when the product has been con-
nected, installed, combined, altered, adjusted, or handled in a manner other than accord-
ing to the instructions furnished with the product, (3) when any serial number has been
effaced, altered, or removed, or (4) when any defect, problem, loss, or damage has re-
sulted from any accident, misuse, negligence, or carelessness, or from any failure to pro-
vide reasonable and necessary maintenance in accordance with the instructions of the
owner’s manual for the product.
We reserve the right to make changes or improvements in our products from time to time
without incurring the obligation to install such improvements or changes on equipment or
items previously manufactured.
This warranty gives you specific legal rights and you may also have other rights which may
vary from state to state.
REMINDER: You must retain the sales slip or sales receipt proving the date of your origi-
nal purchase in case warranty service is ever required.
This warranty does not apply to any database or its contents supplied initially with this
product. For warranty information on the databases and their contents, please refer to the
“Databases Limited Warranty” included with this product.
LOWRANCE ELECTRONICS, INC. 12000 E SKELLY DR TULSA, OK 74128

How to Obtain Service - U.S.A. Only
We back your investment in quality products with quick, expert service
and genuine Lowrance®replacement parts. If you're in the United States
and you have questions, please contact the Factory Customer Service
Department using our toll-free number listed below.You must send the
unit to the factory for warranty service or repair. Please call the factory
before sending the unit.You will be asked for your unit's serial number.
Use the following toll-free number:
800-324-1356
U.S.A.only. Monday through Friday 8:00 A.M. - 8:00 P.M. Central time, except holidays.
Your unit is covered by a full one-year warranty. (See inside this manual
for complete warranty details.) If your unit fails and the failure is not cov-
ered by the original warranty, Lowrance has a flat-rate repair policy that
coversyourunitandaccessories packedwiththe unit atthefactory.There
is a 180-day warranty on all non-warranty repairs from the factory, which
is similar to the original warranty, but is for 180 days rather than one year.
For further details, please call us at the above number.
LITHO IN U.S.A. 988-0061-02 Rev A.
Accessory Ordering Information
To order accessories, please contact:
1)Your local marine dealer.Most quality dealers that handle marine elec-
tronic equipment should be able to assist you with these items. Consult
your local telephone directory for listings.
2) LEI Extras, Inc. P.O.Box 129 Catoosa, OK 74015-0129
or call
800-324-0045
(USA orders only.)
On the internet, http://www.leiextras.com
Lowrance Electronics may find it necessary to change or end our shipping policies, regu-
lations, and special offers at any time.We reserve the right to do so without notice.
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Copyright 2000, Lowrance Electronics, Inc.