VEXILAR LC-8 User manual

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LC-8 Owner's Manual
CONTENTS
General Description 2
Specifications 3
Unit Installation 4
Power Connection 4
Transducer Installation 5 - 6
Operation 7 - 13
Maintenance 14
Trouble Shooting Chart 15
Service and Support 16
Founded in 1965, Vexilar, Inc. has a long histo-
ry of bringing revolutionary technology to the
sport fishing industry. Just some of the Vexilar
firsts include: the first liquid crystal display, the
first fish alarm, the first three color display, and the
first CRT and straight line paper graphs, for the
sport fisherman.

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GENERAL DESCRIPTION
The LC-8 is a compact and lightweight liquid crystal depth
sounder. It indicates depth, shows changes in bottom content, and
conditions. It can also discriminate between large underwater targets,
such as fish, and smaller targets such as bait fish and plankton.
The unit transmits bursts of high frequency pulses, which are con-
verted from electrical to mechanical energy by the transducer. These
"sound" pulses radiate from the transducer downward and are
reflected back up to the transducer where the energy is converted
back to electrical signals. The LC-8 then processes these signals and
displays them. The graphic display is
accomplished by activating
individual or groups of pix-
els, or dots, on the LCD. The
first vertical column of pixels,
on the right edge of the dis-
play, shows the most current
information. This column is
then moved to the next place,
to the left, as soon as a new
column is ready. This process
is repeated continually to
make up the graphic display.
Thus what you see on the dis-
play is a brief history of what
the boat just went over. The LC-8 displays the depth as an easy to
read number in the lower corner of the display
The LC-8 has many functions that can be controlled by the user.
Once you set the unit the way you want it, all of your settings are
saved in memory, so that when the unit is used again no reprogram-
ming is needed.

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SPECIFICATIONS
* Operating Voltage 8.5 - 15 Volts (12 Volts Nominal)
* Current Draw: 50mA or 100 mA with Backlight On
* Power Output: 400 Watts (Peak to Peak)
* Frequency: 200 Khz
* Resolution: 64 x 64 Pixels
* Sounding Rate: 400/Min.
* Display Size: 2" x 2 1/4"
* Dimensions: 5.9"H x 6.4"W x 2.5"D
* Weight: 0.6 Lb.
Depth Ranges:
0-5', 0-10', 0-15', 0-20', 0-30', 0-40', 0-60', 0-80', 0-120', 0-160',
0-240', 0-320', and 0-400'. (Meter units are selectable from the menu.)

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INSTALLATION
To make the LC-8 work, you must provide the unit with power
and mount the transducer in an appropriate location.
UNIT INSTALLATION
Find a convenient place
to mount the unit. This may
include a boat seat, deck,
dash, or a portable case.
Make sure that there is plen-
ty of room for the unit to tilt
and swivel freely without
the cables binding behind
the unit. Once you have
found a spot, securely attach
the bracket to the mounting
surface.
POWER CONNECTION
Plug the round 3 pin connector into the back of the unit. Find the
closest source of 12 volts and run the cord to it. Keep the cord away
from sharp metal edges and avoid tight places where the cord may get
crushed. Connect the white wire to positive and the black wire to
negative or ground. If the cord provided is not long enough, more can
be added. Use 18 gauge wire minimum. It is recommended that the
1 amp in-line fuse be placed in the positive line as close to the power
source as possible to protect against any shorts in the wiring.

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TRANSDUCER INSTALLATION
Transom Mounted
The LC-8 transducer can
be mounted on the transom
of the boat. The shape will
allow a clear depth reading
at any boat speed. Locate a
spot similar to the one in fig-
ure E. Keep in mind that you
need clear water flow across
the face of the transducer to
insure a clear reading at all
speeds. Stay away from riv-
ets, ribs, or strakes that
would be just in front of the
transducer. They will disturb
the water and scramble the
reading. Attach the mount-
ing bracket to the transducer and hold it up to the boat where you are
planning to mount it (see figure E). Mark the first hole on the transom,
or mounting plate, so that when the bottom of the transducer is flush
with the bottom of the boat the hole is located at the bottom of the
bracket slot. This gives you room to "fine tune" the position of the
transducer and optimize your reading after you've put the back boat
in the water. Drill out the hole and tighten the bracket down secure-
ly. Be sure to seal any holes drilled into the transom with silicone to
prevent water from leaking into the boat. Once you have verified that
the unit reads at all boat speed, drill out the second hole and install the
second mounting screw. Run the transducer cord up to the unit tak-
ing the same care as you did when you ran the power cord. Plug the
transducer connector into the back of the unit and screw the retaining
ring down tight.

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In-Hull Mounting
This method, gluing the transducer to the hull, gets the same
results as if you were mounting the transducer externally, only there
are no holes to drill in the boat and there is no transducer on the tran-
som to get damaged by impact.
Finding the best location for the transducer before mounting is
critical. Choose a flat smooth spot near the center of the bilge and
near the back of the boat. It is a good idea to make a "test run" before
you permanently install the transducer to make sure that you can
indeed get a reading through your hull, and when the boat is on
plane. Put about a half inch of water in the bilge and hold the trans-
ducer in the intended location. Move the transducer around until you
get the best reading. Mark the spot.
To install the transducer clean the spot of mud and oil. Using an
epoxy or silicone glue make a puddle, about the same size as the
transducer, on the hull. Place the transducer in the glue. Press it
down firmly, gently twisting it back and forth, making sure that there
are no air bubbles in the glue between the transducer and the hull. Let
the glue dry completely before turning the unit on.
Run the transducer cord up to the unit taking the same care as you
did when you ran the power cord. Plug the transducer connector into
the back of the unit and screw the retaining ring down tight.
PORTABLE MOUNTING
An optional suction cup bracket can be used to temporarily attach
a transducer to the transom or side of the boat. The cup should be
placed in a location where it will not be torn off when the boat goes
high speed. It is a good idea to tie on a safety rope in case the cup does
let go. An arm can also be used to hold the transducer. Simply attach
the transducer to the end of the arm using cable ties or tape. Plug the
transducer connector into the back of the unit and screw the retaining
ring down tight.

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OPERATION
This figure shows the main controls of the LC-8
DEPTH CONTROL
The two buttons at the top of the control panel set the depth range
when the unit is in Manual Depth Mode. Pressing the SHALLOW
button changes the range to the next shallowest range. Pressing the
DEEP button changes the range to the next deeper range.
GAIN CONTROL
While in Manual Gain Mode, pressing the DEC button decreases
the gain one step. Pressing the INC button increases the gain one step.
There are 8 steps of Gain control. Different conditions will require dif-
ferent gain settings. Deeper water will require higher gain than shal-
low water. A weedy bottom will demand a lower gain setting than a
clean bottom. Keep the gain level low. Too much gain can "wash out"
the targets that you want to see. Generally, it is a good idea to set the
gain at an appropriate level and leave it there. Only change the gain
level if the water depth or conditions change.

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ZOOM
ZOOM displays only the bottom half of the water depth. This
doubles the display resolution making it much easier to see targets
near or on the bottom. Pressing the ZOOM button once puts the LC-
8 in ZOOM mode. Pressing it again will go back to the normal view.
SWEEP
SWEEP controls how fast the information moves across the dis-
play. There are 4 steps of sweep speed. The sweep speed should
roughly match the boat speed to get the most accurate reading.
FREEZE/RESUME
The FREEZE button stops the display so that you can examine it
before it moves off of the screen. Pressing it again will RESUME the
display back to the original speed.
MENU
Pressing the MENU button opens the first menu page. Pressing it
again will go to menu page two, and pressing it again will go to page
three. Pressing the MENU button when you are on page three, the last
menu page, will send you back to page one. On each page you will
see a list of Submenus. Each item will be explained in the next section.
To resume to normal operation press the RESUME button.
ON/OFF
Simply turns the LC-8 ON and OFF. When you turn the LC-8 off
all of your menu and control settings will be saved in memory so that
when you turn it on again the unit will operate the same way as it did
when you last turned it off.
MENU SETTINGS
When you are in the MENU mode, the control panel buttons act
as input keys. You no longer read the descriptions, in white. Instead,

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you read the blue numbers. For instance the SHALLOW button is the
1 key and the DEC button is the 2 key in Menu Mode.
MENU PAGE 1
1 - AUTO - R
Press the 1 key to enter the Automatic Range Submenu. In this
submenu, pressing the 2 key puts the LC-8 into Automatic Range
Mode. In this mode the unit changes the range setting for you when
the depth of the water changes. Pressing the 2 key puts the unit into
the Manual Range Mode. The unit will not change range settings until
you press the SHALLOW or DEEP button on the control panel. The
factory default setting is ON.
2 - AUTO - G
Press the 2 key to enter the Automatic Gain Submenu. In this
submenu, pressing the 2 or 3 key puts the LC-8 into Automatic Gain
Mode. The 2 selection tends to keep the gain on the higher side and
the 3 selection will keep it on the lower side. The factory default set-
ting is ON<High>. In shallow or weedy water it is recommended that
the <LOW> setting be used. Pressing the 1 key takes the unit out of
Automatic Gain Mode. No changes will take place unless you use the
control panel.
3 - LIGHT
Press the 3 key to enter the Backlight Submenu. Press the 2 key to
turn the backlight on, for night use. Press the 1 key to turn the back-
light off.
4 - BOTT-ALM
Press the 4 key to enter the Bottom Alarm Submenu. Press the 2
key to activate the Bottom Alarm. The current setting is displayed at
the bottom of the screen. This setting can be decreased by pressing the

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4 key. As you press the key the displayed setting will change. Press
the key until it is set to where you want it. The minimum is 3 feet.
Press the 5 key to increase the setting. There is no maximum limit.
Press the 1 key to turn the Bottom Alarm off. The default is OFF.
5 - FISH-ALM
Press the 5 key to enter the Fish Alarm Submenu. Press the 2 or 3
key to turn the Fish Alarm on. When the 2<HIGH> selection is cho-
sen the alarm will sound on all fish targets that the LC-8 sees. When
the 3<LOW> selection is chosen it will only sound on larger fish tar-
gets. Press the 1 key to turn the Fish Alarm off. The default is OFF.
6 - CONTRAST
Press the 6 key to enter the Contrast Adjust Submenu. Press the 4
key to decrease the display contrast or press the 5 key to increase the
display contrast.
MENU PAGE 2
1 - C-ECHO
Press the 1 key to enter the Clean Echo Submenu. Clean Echo
helps reduce noise and interference from other nearby depthfinders
running on the same frequency. Press the 2 key to turn Clean Echo on
and the 1 key to turn it off. The default setting is ON.
2 - C-LINE
Press the 5 key to enter the Clean Line Submenu. Clean Line is
similar to the White or Gray Line feature. It helps you discriminate
fish from the bottom. With this feature off, the bottom is solid black
and fish that are on or near the bottom will be difficult to determine.
With the Clean Line feature on, the bottom will be "cleaned out" and
these fish will be much more visible. Press the 3 key to turn the fea-
ture on to the <LOW> setting. This is the default. Press the 2 key to

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set the feature to the <HIGH> setting. Press the 1 key to turn the fea-
ture off.
3 - A-MODE
Press the 3 key to enter the A-Mode Submenu. A-Mode gives you
a vertical representation of the depth. Everything displayed is hap-
pening right now. Press the 2 key to select the normalA-Mode setting.
This is a "split screen" display. The vertical display will be at the right
side and the left side will continue to show the normal graphical rep-
resentation of the bottom. Press the 3 key to activate the Wide setting.
A-Mode will now cover the entire display. This is the recommended
setting for vertical jigging or ice fishing. Press the 1 key to turn the A-
Mode off. This is the default.
4 - DIGITAL
Press the 4 key to enter the Digital Depth Size Submenu. Press the
2 key to make the digital depth display show large numbers. Press the
1 key to display them in normal size.
5 - DEPTH
Press the 5 key to enter the Depth Range Submenu. Press the 1
key to activate the SHALLOW setting. The maximum range of the
LC-8 will be 120 feet. Press the 2 key to activate the DEEP setting. The
maximum range will now be 400 feet. The default is SHALLOW.
6 - UNIT
Press the 6 key to enter the Unit Selection Submenu. Press the 1
key to use feet or the 2 key to use meters. The default is FEET.
MENU PAGE 3
1 - SIMULATE
Press the 1 key to enter the Simulator Submenu. The simulator

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allows you to test all of the control panel and menu functions without
having to be on the water. It displays a short program of what you
may see when you are actually out on the water. Press the 2 key to
activate the simulator and the 1 key to deactivate it.
2 - OFFSET
Press the 2 key to enter the Keel Offset Submenu. The feature
allows you to compensate for the depth that the transducer is under
the surface of the water. For example, if you transducer sits a foot
below the surface when your boat is in the water than you would set
the Keel Offset to 1 foot. This foot will be added to the displayed
water depth. The depth that is displayed will now be accurate.
3 - RESET
Press the 5 key to enter the System Reset Submenu. Press the 2
key to erase all of your settings and return to the factory default set-
tings.
HIGH SPEED OPERATION
The LC-8 can read depths at almost any boat speed. Due to the
limited speed of the display, the displayed bottom may be some dis-
tance behind you, depending on how fast the boat is traveling Here
high speed is defined as any speed at or above the planning speed of
the boat. Once the boat starts to plane out, turbulence will develop
behind the transom. If your transducer is poorly mounted, the unit
will lose the bottom at a certain boat speed. This is due to all of the
air bubbles in the turbulent water. Readjustment of the transducer
mounting should solve this problem.
ICE FISHING
The stable platform of ice lets you concentrate on your bait and
the fish around it. The bottom becomes less important because it
never changes. The only movement on the display is of your bait and
fish.

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Unlike open water use, the direction in which the transducer is
pointed is very critical. You want your bait to be located in the dead
center of the cone sound, directly under the transducer. This way you
can see very small baits at low gain settings and also see fish come in
from all sides. If you are not using the Ice-Ducer system, the trans-
ducer must be attached to an adjustable arm so that it can be manual-
ly pointed directly at the bait. Sometimes it helps to attach a bubble
level to the transducer so that you know when it's straight.
After your system is properly set up, adjust the gain until you see
your bait. You may need to readjust the gain control to keep the bait
in view. This is due to the changing condition and position of your
bait. If you are using a swimming bait or a lure that darts to the side
as it's jigged, you will see the signal change as the bait moves.
Sometimes it may even disappear if the bait goes out of the cone of
sound.

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MAINTENANCE
PERMANENT MOUNT
With permanent mount applications, the power cord is left con-
nected to the source, the transducer is not easily removed, and the
gimbal bracket is screwed to the seat, deck, or dash. Under these con-
ditions maintenance is very simple because nothing changes once the
unit is installed. Because of this, though, problems can sneak up on
you if you're not careful.
Power connections need constant checking. Corrosion can devel-
op and cause intermittent or loss of operation. Connections made to
battery posts need extra attention because of the battery acid.
The transducer should be checked for scratches and cracks which
can reduce the units sensitivity. Cuts or breaks in the cord should be
repaired as soon as possible so corrosion doesn't attack the wire.
Periodically clean the face of the transducer with a mild detergent. An
oily film can develop which will cause weak readings.
PORTABLE MAINTENANCE
In portable applications the unit is generally mounted to a carry-
ing case and the transducer is frequently removed, as is the power.
These conditions can cause more wear and tear than a permanently
mounted unit.
In addition to the previously mentioned maintenance items, be
sure to check for broken or pulled wires, loose screws or hardware,
and, above all, battery condition.

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Trouble Shooting Chart

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Service and Support
If you find that you need help, feel free to contact us. Please have
ready the model number and, if possible, the serial number of your
product. Be sure to read the Trouble Shooting sections first.
Address
Vexilar, Inc.
200 W. 88th St.
Minneapolis, MN, 55420-2752
Telephone
[phone] (8 am to 5 PM M-F Central Time)
Fax [phone]
Email [e-mail]
Web Site
www.vexilar.com