Section 1: Read Me First!
If you're having difficulty with your sonar, you can find an answer to the most common problems in Section 5, Sonar Troubleshooting. Finally, in Section 6, we offer Supplemental Material, including a list of warranty and customer service information. Now, if you're into the fine details, glance over the next segment on specifications to see just how much sonar power your unit contains. It's important to us (and our power users), but, if you don't care how many watts of power the unit has, skip ahead to important information on how sonar works, on page 3. Capabilities and Specifications: X102C, X107CDF General Display:.. 5.0" (12.7 cm) diagonal high color contrast Film SuperTwist; programmable to viewing preference. Resolution:.. 480 pixel x 480 pixel resolution ; 230,400 total pixels. Backlighting:. X102C, X107CDF White LED backlit screen and keypad. Input power:. 10 to 15 volts DC. Case size:.. 5.4" H x 6.9" W x 3.4" D (13.8 x 17.6 x 8.6 cm); sealed and waterproof; suitable for saltwater use. Back-up memory:.. Built-in memory stores sonar records for decades. Languages:.. 10; menu languages selectable by user. Sonar Frequency:.. 50/200 kHz for X107CDF; 200 kHz for X102C. Transducers:. A dual-frequency Skimmer transducer with built-in temperature sensor is packed with the X107CDF. It has 35/12 cone angles. A single-frequency with built-in temperature sensor is packed with the X102C. It has a 20 cone angle. Transducers operate at speeds up to 70 mph (61 kts). Transmitter:. X107CDF: 2
4,000 watts peak-to-peak/500 watts RMS. X102C: 2,400 watts peak-to-peak/300 watts RMS. Sonar sounding depth capability:. X107CDF: 2,500 feet (762 meters). X102C: 800 feet (244 meters). Actual capability depends on transducer configuration and installation, bottom composition and water conditions. All sonar units typically read deeper in fresh water than in salt water. Depth display:. Continuous display. Audible alarms:. Deep/shallow/fish/zone. Automatic ranging:. Yes, with instant screen updates. Auto bottom track:. Yes. Zoom bottom track:. Yes. Split-screen zoom:. Yes. Surface water temp:.. Yes. Speed/distance log:. Optional (requires optional speed sensor). NOTICE! The storage temperature range for your unit is from -4 degrees to +167 degrees Fahrenheit (-20 degrees to +75 degrees Celsius). Extended storage in temperatures higher or lower than specified will damage the liquid crystal display in your unit. This type of damage is not covered by the warranty. For more information, contact the factory's Customer Service Department; phone numbers are listed on the last page.

How Sonar Works

Sonar has been around since the 1940s, so if you already know how it works, skip ahead to the next segment on the typographical conventions used in this manual. But, if you've never owned a sonar fish finder, this segment will tell you the under water basics. Sonar is an abbreviation for SOund NAvigation and Ranging, a technology developed during World War II for tracking enemy submarines. (Lowrance developed the world's first transistorized sportfishing sonar in 1957.) A sonar consists of a transmitter, transducer, receiver and display. In simple terms, here's how it finds the bottom, or the fish: 3

Lock washer Nut

Flat washer
Assemble transducer and bracket.
3. Assembling the transducer. A. One-piece bracket: Once you determine the correct position for the ratchets, assemble the transducer as shown in the following figure. Don't tighten the lock nut at this time.

Nut Metal washer

Rubber washers

Metal washer Bolt

B. Two-piece bracket: Once you determine the correct position for the ratchets, assemble the transducer as shown in the figure in step 2B. Don't tighten the lock nut at this time. 4. Drilling mounting holes. Hold the transducer and bracket assembly against the transom. The transducer should be roughly parallel to the ground. The transducer's centerline should be in line with the bottom of the hull. Don't let the bracket extend below the hull! Mark the center of each slot for the mounting screw pilot holes. You will drill one hole in the center of each slot. Drill the holes. For the one-piece bracket, use the #29 bit (for the #10 screws). For the two-piece bracket, use the #20 bit (for the #12 screws). 14

Transom Transom

Position transducer mount on transom and mark mounting holes. Side view shown, left, and seen from above at right.
5. Attaching transducer to transom. A. One-piece bracket: Remove the transducer from the bracket and re-assemble it with the cable passing through the bracket over the bolt as shown in the following figures.
For single-frequency Skimmer, route cable over bolt and through bracket. Side view shown, left, and seen from above at right.
Both bracket types: Attach the transducer to the transom. Slide the transducer up or down until it's aligned properly with the bottom of the hull as shown in the preceding and following figures. Tighten the bracket's mounting screws, sealing them with the sealant. Adjust the transducer so that it's parallel to the ground and tighten the nut until it touches the outer washer, then add 1/4 turn. Don't over tighten the lock nut! If you do, the transducer won't "kick-up" if it strikes an object in the water.

Bottom of hull

Flat-bottom hull Deep-"vee" hull Align transducer centerline with hull bottom and attach transducer to transom. Rear view of dual-frequency Skimmer shown.
6. Route the transducer cable through or over the transom to the sonar unit. Make sure to leave some slack in the cable at the transducer. If possible, route the transducer cable away from other wiring on the boat. Electrical noise from the engine's wiring, bilge pumps, VHF radio wires and cables, and aerators can be picked up by the sonar. Use caution when routing the transducer cable around these wires. WARNING: Clamp the transducer cable to the transom close to the transducer. This can prevent the transducer from entering the boat if it is knocked off at high speed. If you need to drill a hole in the transom to pass the connector through, the required hole size be 1". Caution: If you drill a hole in the transom for the cable, make sure it is located above the waterline. After installation, be sure to seal the hole with the same marine grade above- or below-waterline sealant used for the mounting screws. 7. Make a test run to determine the results. If the bottom is lost at high speed, or if noise appears on the display, try sliding the transducer bracket down. This puts the transducer deeper into the water, hopefully below the turbulence causing the noise. Don't allow the transducer bracket to go below the bottom of the hull!

Trolling Motor Bracket Installation (single-frequency only) 1. Attach the optional TMB-S bracket to the transducer as shown in the following figure, using the hardware supplied with the transducer. (Note: The internal tooth washer is supplied with the TMB-S.)
Internal tooth washer Bolt Nut TMB-S bracket
Flat washer Attach motor mounting bracket to transducer.
2. Slide the adjustable strap supplied with the TMB-S through the slot in the transducer bracket and wrap it around the trolling motor. Position the transducer to aim straight down when the motor is in the water. Tighten the strap securely. 3. Route the transducer cable alongside the trolling motor shaft. Use plastic ties (not included) to attach the transducer cable to the trolling motor shaft. Make sure there is enough slack in the cable for the motor to turn freely. Route the cable to the sonar unit and the transducer is ready for use.
Transducer mounted on trolling motor, side view.
Transducer Orientation and Fish Arches If you do not get good fish arches on your display, it could be because the transducer is not parallel with the ground when the boat is at rest in the water or at slow trolling speeds. 17

Partial fish arches

Transducer aimed too far back
Transducer aimed too far forward
Full fish arch Proper transducer angle Transducer angles and their effects on fish arches.
If the arch slopes up but not back down then the front of the transducer is too high and needs to be lowered. If only the back half of the arch is printed, then the nose of the transducer is angled too far down and needs to be raised. NOTE: Periodically wash the transducer's face with soap and water to remove any oil film. Oil and dirt on the face will reduce the sensitivity or may even prevent operation. Shoot-Thru-Hull Preparation
Hulls With Floatation Materials
The transducer installation inside a fiberglass hull must be in an area that does not have air bubbles in the resin or separated fiberglass layers. The sonar signal must pass through solid fiberglass. A successful transducer installation can be made on hulls with flotation materials (such as plywood, balsa wood or foam) between layers of fiberglass if the material is removed from the chosen area. See the following figure. 18

Second bottom

Manual range setting

Example of a second bottom signal. Unit is in 30 feet of water, with range set at 80 feet and sensitivity set at 87 percent.
2. Next, take the transducer out of the water and place it in the water in the sump of the boat, face down. (The transducer face is shown in the figure on the following page.) Notice how the signal strength decreases. The second bottom signal will probably disappear and the bottom signal intensity will likely decrease. 3. Now move the transducer around to find the best location with the strongest possible bottom signal. If you find a spot with an acceptable bottom signal, mark the location and move on to step 4. If you can't get an acceptable bottom signal, try turning up the sensitivity by three or five keystrokes and then move the transducer around once more. If you find a spot that works, mark it and move on to step 4. If you have to turn up sensitivity by more than five keystrokes to get a good signal, the transducer should be mounted on the outside of the hull. This is especially true if you have to turn sensitivity all the way up to get a decent bottom signal. 20
4. Most people can get good results by following steps 1 through 3, so this step is optional. If you want to make an extra effort to be absolutely sure that your selected location will work under all conditions, make a test run with the boat on plane and observe the bottom signal. You'll need to figure some way to prop the transducer into position while you make your test run. (A brick or two might be sufficient to hold it in place.) 5. When you're satisfied with a location, mark it and proceed with the installation. Shoot-thru-hull Installation If you are installing the transducer on a hull with floatation material sandwiched within the hull, refer to the text "Hulls With Flotation Materials" beginning on page 18. 1. Make sure the area is clean, dry and free of oil or grease, then sand both the inside surface of the hull and the face of the transducer with 100 grit sandpaper. The sanded hull area should be about 1-1/2 times the diameter of the transducer. The surface of the hull must be flat so the entire transducer face is in contact with the hull prior to bonding. After sanding, clean the hull and transducer with rubbing alcohol to remove any sanding debris.

Spread epoxy here

Sand this surface (unit's face) Orient the Skimmer with the nose facing the bow of the boat. To bow

sor on the transom. The bottom of the bracket should be flush with the hull's bottom. Using the sensor as a template, mark the hull for the screws' pilot holes. Drill four 1/8" holes, one in each end of the slots. Mount the sensor to the hull using #8 stainless steel wood screws (not included). Use a high quality, marine grade above- or below-waterline sealant to seal the screws. Make sure the sensor is flush with the bottom of the hull and tighten the screws.
Good location Stern view showing good location for mounting sensor on transom. Transom
Bottom of hull Speed sensor mounting configuration: side view (left) and rear view (right.)
If the base of the transom has a radius, fill the gap between the transom and the sensor with the sealant. This will help ensure a smooth water flow. Route the sensor's cable through or over the transom to the sonar unit. If you need to drill a hole in the transom to pass the connector through, the required hole size is 7/8". CAUTION: If you drill a hole in the transom for the cable, make sure it is located above the waterline. After installation, be sure to seal the hole with the same marine grade above- or below-waterline sealant used for the screws. The sensor is now ready for use. Connect the sensor to the sonar socket on the back of your unit and connect the transducer to the speed sensor's socket. If you have any questions concerning the installation of the sensor, please contact your local boat dealer. 23

Sonar socket

Sonar unit, rear view

Network socket

Power/Data socket
SP-BL optional speed sensor
NMEA 0183 data cable Unused wires
NMEA 2000 buss adapter cable

Power Supply cable

Transducer

NMEA 2000 Power cable

To NMEA 2000 buss
Sonar unit cable connections.

Power Connections

Your unit comes with a power/data cable that splits into three ends, each with several exposed wires (shown in the following figure). The end with 4 wires (blue, yellow, orange and shield will not be used with your unit. The end with three wires (red, black and shield) is a power cable that connects to a NMEA 2000 buss. The thicker three-wire cable (red, black and white) is the Power Supply for your unit (and optional 24
external speaker connection for some units).
Power Supply wires: red, black and white To unit
NMEA 2000 Power wires: red, black and shield
The Power/Data cable for this unit.

Unused wires

Depending on your configuration, you may not use all of these wires. (For example, many units cannot operate an optional external speaker, so the white wire on the Power Supply cable isn't functional.) The following segments include instructions for installing all the wires that you will use with this unit. Caution: All of the wires in the power/data cable have bare ends for easier installation. The bare ends on any unused wires could cause an electrical short if left exposed. To prevent this, you should cover the individual wire ends either by capping them with wire nuts or wrapping them with electrical tape. (You should cut off the bare wire before taping off the ends.) Powering a NMEA 2000 Buss (NMEA 2000 Power cable) A NMEA 2000 buss must be connected to a power source to operate. If you have a pre-existing NMEA 2000 installation, it may already be connected to another power source. If your NMEA 2000 buss is already powered, you can ignore the NMEA 2000 Power cable. Never attach two power sources to a single NMEA 2000 buss. If you do need to power your NMEA 2000 buss, attach the NMEA 2000 Power cable to your boat's battery just as indicated in the following segment for connecting your unit's Power Supply cable. The NMEA 2000 Power cable's red wire should be attached (with provided 3-amp fuse) to the boat battery's positive terminal, and the NMEA 2000 Power cable's black and shield wires should both be attached to the battery's negative terminal. NOTE: If your boat does not have a NMEA 2000 buss, do not connect the NMEA 2000 wires! 25

NMEA 0183 Cable Connections
NMEA is a standard communications format for marine electronic equipment, mainly navigation equipment. Your sonar unit cannot currently communicate with the NMEA 0183 format, so the Data cable wires will not be used. 27
Mounting the Unit: Bracket, In-Dash or Portable
You can install the sonar unit on the top of a dash with the supplied gimbal bracket. It can also be installed in the dash or mounted on a portable power supply. If you use the supplied bracket, you may be interested in the optional R-A-M bracket mounting system. This converts the unit's gimbal bracket to a swivel mount, which can be used on the dash or overhead mounting positions. Installation instructions are supplied with the R-A-M mounting kits.
Optional R-A-M mounting system.
Bracket Installation Mount the unit in any convenient location, provided there is clearance behind the unit when it's tilted for the best viewing angle. You should also make sure there is enough room behind the unit to attach the power and transducer cables. (A drawing on the next page shows the dimensions of a gimbal-mounted sonar unit.) Holes in the bracket's base allow wood screw or through-bolt mounting. You may need to place a piece of plywood on the back side of thin fiberglass panels to reinforce the panel and secure the mounting hardware.
Install the gimbal bracket. Orient the bracket so the arms slope toward the front of your unit.
Drill a 1-inch (25.4 mm) hole in the dash for the power and transducer cables. The best location for this hole is immediately under the gimbal bracket location. This way, the bracket can be installed so that it covers the hole, holds the cables in position and results in a neat installation. Some customers, however, prefer to mount the bracket to the side of the cable hole it's a matter of personal preference.
72.9 [2.87] 173.9 [6.85] 23.4 [0.92]

137.9 [5.43]

157.9 [6.22]

Millimeter [Inch]

56.9 [2.24]
Front view (left) and side view (right) showing dimensions of the sonar unit when mounted on gimbal bracket.

Main Menu. Main Menu Commands
There are four "basic" Main Menu commands that you'll really want to read more about. They are: Screen command: changes the contrast or brightness of the display screen. Use this command to adjust how the screen looks under various lighting conditions. Sounds command: enables or disables the sounds for key strokes and alarms, controls the volume and sets the alarm style. If you don't like to hear a beep each time you press a key, you can turn this off, or select tunes or sound effects instead. The sounds are especially useful when used with the Fish I.D. fish symbol feature and fish alarm feature. Sonar Alarms command: turns alarms on or off and changes alarm thresholds. The fish alarm, used with Fish I.D., is the most popular use. It tells you when the sonar sees a fish. You can also set deep or shallow depth alarms and zone alarms. Popup Help command: turns the pop-up help boxes on or off. When you select a menu command, these information boxes appear to tell you what the command does or how to use the command. The default setting is on, which is really handy while you're learning. The remaining Main Menu commands are for more advanced functions, mostly setting various sonar options. (They're all detailed in Sec. 4.) Transparency command: adjust the level of transparency for menus. Units of Measure command: selects the units of measure used for showing speed/distance, depth and temperature. Set Keel Offset command: calibrates the unit to show depth under the keel or actual depth from the surface. 35
Calibrate Water Speed command: adjusts how a speed sensor measures water speed. Reset Water Distance command: resets water distance log to zero. Sonar Simulator command: turns the simulator feature on and off. Useful for learning how to operate the unit and all its functions. Transducer Type command (dual-frequency units only): sets the type of transducer plugged into the unit. Reset Options command: returns all options and auto functions to their original factory settings. It's a great safety net while you're learning and experimenting with various settings. Set Language command: your unit has menus in 10 different languages. This command switches from one language to another. Software Information command: tells you which version of the operating software is loaded in your unit. Sonar Menu The Sonar Menu contains commands for the major sonar features and options. You access the Sonar Menu by pressing the MENU key one time. You run a command by using the or to highlight the command and then pressing ENT. To clear the menu screen and return to the Page display, press EXIT.

Sonar Page Menu. Most of these functions are discussed in Sec. 4. Sonar Menu Commands
The Sonar Menu contains commands for the major sonar features and options. Most of them are only described in detail in Sec. 4, but Sensitivity and Auto Sensitivity are important basic functions that are discussed both here and in Sec. 4. The other Sonar Menu commands include: Colorline command: separates fish and structure near the bottom from the actual bottom, and defines bottom composition and hardness. 36
Depth Range command: manually sets the depth range shown on the sonar chart. Auto Depth Range command: automatically sets the depth range shown on the sonar chart to always keep the bottom in view. Upper and Lower Limits command: sets the upper and lower depth limits of the sonar chart. Lets you zoom in on a specific portion of the water column. Stop Chart command: stops the sonar chart from scrolling. Used when you want to "freeze" the image for closer study. Chart Speed command: sets the scrolling speed of the sonar chart. Depth Cursor command: displays a cursor line on the sonar chart which allows you to accurately measure the depth of a sonar target. Overlay Data command: chooses what types of information (such as water temperature) to show overlaid on the sonar chart screen. Sonar Features command: launches the Sonar Features menu which controls many functions and options, including frequency selection, screen color mode, auto depth and sensitivity, surface clarity, noise rejection, Fish I.D. symbols, the zoom bar and zone bar. Ping Speed command: sets the rate at which sonar pings are made.
The Pages Menu controls the five major display options. They are the Full Sonar Chart, Split Zoom Sonar Chart, Split Frequency Sonar Chart, Digital Data and the flasher-style FlashGraf. You access the Pages Menu by pressing the PAGES key. You select a display option by using or to highlight the option and then pressing ENT. (You can clear the Pages Menu by pressing EXIT.)
Pages Menu showing some Sonar display options (left, dual-frequency menu; right, single-frequency menu).
The Full Sonar Chart is the main display option. This is a "crosssection" view of the water column beneath the boat. The chart moves across the screen, displaying sonar signal echoes that represent fish, structure and the bottom.

Left, Sonar Menu with Sensitivity command selected. Right, the Sensitivity Control Bar.
NOTE: If you want to change the sensitivity in Manual Mode, first turn off Auto Sensitivity: from the Sonar Page, press MENU| to AUTO SENSITIVITY|ENT| to SENSITIVITY|ENT. Press or to pick a different sensitivity setting. When it's set at the desired level, press EXIT.

Important Tip:

While you are experimenting and learning, it's possible to scramble the settings so that the sonar picture disappears from your screen. If that happens, remember that it's easy to switch back to full automatic operation by simply restoring the factory auto settings. Here's how:
To Restore Factory Settings 1. Press MENU|MENU| to RESET OPTIONS|ENT.
2. The unit asks if you want to reset all the options. Press to YES|ENT. All options are reset, and the unit reverts back to the original settings. Fish Symbols vs. Full Sonar Chart You may have noticed in the quick reference that we used fish arches in full sonar chart mode for our example, and not the popular Fish I.D. fish symbol feature. Here's why. Fish I.D. is an easier way for a sonar novice to recognize a fishy signal return when he sees it. However, locating fish by symbol only has some limitations. Your sonar unit's microprocessor is remarkably powerful, but it can be fooled. Some of the echoes calculated to be fish could be tree limbs or turtles! To see what's under your boat in maximum detail, we recommend you turn off Fish I.D. and begin learning to interpret fish arches. Fish I.D. is most handy when you're in another part of the boat or performing some task that prevents you from watching the sonar screen. Then, you can turn on Fish I.D. and the audible fish alarm. When that lunker swims under your boat, you'll hear it! Fish I.D. can also be useful when you want to screen out some of the sonar detail gathered by your unit. For example, in one case fishermen in San Francisco Bay saw clouds of clutter in the water but no fish arches. When a down rigger was pulled up, it brought up several small jellyfish. The fishermen switched their Lowrance sonar to Fish I.D., which screened out the schools of jellyfish and clearly showed the game fish there as fish symbols. 43
Other Free Training Aids The sonar options section discusses Fish I.D., fish alarms and other features in greater detail. If you or a friend has Internet access, you can also learn more about interpreting what you see on your sonar screen. Visit our web site, WWW.LOWRANCE.COM. Be sure to check out the free Sonar Tutorial, which includes animated illustrations and more pictures of actual sonar returns, all described in detail. There's even a "printer friendly" version of the tutorial available on our web siteit makes a great supplement to this operation manual! For the ultimate training aid, be sure to download the free emulator software for your unit. Aside from being just plain fun, this program can help you learn both basic and advanced operations without burning boat fuel! Lowrance is the first sonar manufacturer to provide this type of training tool for customers. This PC application simulates the actual sonar unit on your computer. You can run it from your computer keyboard or use your mouse to press the virtual keys. Easy download and installation instructions are available on our web site.

To turn off upper and lower limits 1. From the Sonar Page, press MENU| to AUTO DEPTH RANGE|ENT|EXIT.

FasTrack

This feature automatically converts all echoes to short horizontal lines on the display's far right side. The graph on the rest of the screen continues to operate normally. FasTrack gives you a rapid update of conditions directly under the boat. This makes it useful for ice fishing, or when you're fishing at anchor. When the boat is not moving, fish signals are long, drawn out lines on a normal chart display. FasTrack converts the graph to a vertical bar graph that, with practice, makes a useful addition to fishing at a stationary location.
Surface clutter Fish arches Structure In FasTrack, fish arches show as horizontal bars.

Bottom signal

Sonar Page showing FasTrack.
Fish I.D. (Fish Symbols & Depths)
The Fish I.D. feature identifies targets that meet certain conditions as fish. The microcomputer analyses all echoes and eliminates surface clutter, thermoclines, and other signals that are undesirable. In most instances, remaining targets are fish. The Fish I.D. feature displays fish symbols on the screen in place of the actual fish echoes. There are several fish symbol sizes. These are used to designate the relative size between targets. In other words, Fish I.D. displays a small fish symbol when it thinks a target is a small fish, a medium fish symbol on a larger target and so on. The sonar's microcomputer is sophisticated, but it can be fooled. It can't distinguish between fish and other suspended objects such as trotlines, turtles, submerged floats, air bubbles, etc. Individual tree limbs extending outwards from a group of limbs is the hardest object for the Fish I.D. feature to distinguish from fish. You may see fish symbols on the screen when actually, there are no fish. The reverse is also true. The illustrations on the next page show how Fish I.D. can actually miss fish that are present. Does that mean Fish I.D. is broken? No the feature is simply interpreting sonar returns in a specific way to help take some of the work out of reading the screen. Remember: Fish I.D. is one of the many tools we provide so you can analyze your sonar returns for maximum fish finding information. This and other features can help you successfully "see" beneath the boat under varied water and fishing conditions. So, practice with the unit in both the Fish I.D. mode and without to become more familiar with the feature. The default for Fish I.D. is off.

Sonar Features menu with Fish I.D. Symbols selected (Left, dualfrequency menu; right, single-frequency menu). When the check box to the left is checked, the feature is on.

Fig. 1A

Fig. 1B
Many fish arches visible Fig. 2A Fish arches above structure
Fewer fish symbols visible Fig. 2B No fish shown
FasTrack graph confirms fish above structure Left, figures 1A and 2A show Sonar Page in normal chart mode. Right, figures 1B and 2B show the same underwater scene with Fish I.D. turned on. Note how arches are replaced with symbols.
To turn the Fish I.D. feature on 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press to FISH SYMBOLS|ENT|EXIT|EXIT. To turn off Fish I.D., repeat the instructions in step 2.

FishTrack

The FishTrack feature shows the depth of a fish symbol when it appears on the display. This lets you accurately gauge the depth of targets. This feature is available only when the Fish I.D. feature is on. The default setting for FishTrack is off. To turn on FishTrack 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press |then press to FISH DEPTHS|ENT|EXIT|EXIT. 56
NOTE These instructions will turn on FishTrack and Fish I.D. at the same time. To turn off FishTrack, repeat the instructions in step 2. Turning off FishTrack in this manner will not turn off Fish I.D. symbols.
Symbols with FishTrack depths
Sonar Features menu with Fish I.D. Depths selected (Left, dualfrequency menu; center, single-frequency menu). When the check box to the left is checked, the feature is on. Right, Sonar Page showing Fish I.D. symbols and FishTrack depths turned on.
Frequency (Change Transducer Frequency) (X107CDF only)
The "DF" in your unit's name refers to its dual-frequency transducer, which operates with both 200 kHz and 50 kHz. The 200 kHz frequency has a 12 cone angle and the 50 kHz frequency has a 35 cone angle. The default frequency is 200 kHz, which is best for use in shallow water (about 300 feet or less). This frequency is the best choice for about 80 percent of the fresh and saltwater sport fishing applications. When you get into very deep saltwater 300 to 500 feet or deeper the 50 kHz frequency is the best choice. The 200 kHz transducer will give you better detail and definition, but less depth penetration. The 50 kHz transducer will give you greater depth penetration, but a little less detail and less definition. (Remember, all sonar units typically read deeper in fresh water than in saltwater.) There is a common exception to these rules. Some fishermen, who use downriggers on freshwater lakes (or the ocean), like to see their bait on the sonar. In many of those cases, you'll see a 50 kHz transducer frequency in use because the wider cone angle.

Sonar Features menu with a frequency of 200 kHz selected.
To change the frequency setting to 50 kHz 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press |then press to 50 KHZ|ENT. 3. Press EXIT|EXIT to clear the menu. To change the frequency setting to 200 kHz 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press |then press to 200 KHZ|ENT. 3. Press EXIT|EXIT to clear the menu.

HyperScroll

See the entry on Ping Speed, which controls the HyperScroll feature.

Noise Rejection

See the entry on Advanced Signal Processing in this section.

Overlay Data

To change the digital data shown on top of the sonar page: 1. Press MENU| to OVERLAY DATA|ENT. 2. Press or to select Data Type|ENT.
Left, Overlay Data command on the Sonar Menu. Overlay Data Shown selection menu, right.
When selected, the data type shifts to the top of the data list and a check mark appears beside the data type. (If you wish, you may now use or to select other Data Types for display.)
Data list showing "Water Speed" selected to display on Sonar Page.
3. To return to the previous page, press EXIT.
To turn off displayed data 1. Press MENU| to OVERLAY DATA|ENT.
2. Press or to select Data Type|ENT. The selected data type disappears from the top of the list and reverts to its previous, unchecked position. (If you wish, you may now use or to select other Data Types to turn off.) 3. To return to the previous page, press EXIT.
To change displayed data font size 1. Press MENU| to OVERLAY DATA|ENT.
2. Press or to select Data Type|press or to Data Size|EXIT. The selected data type will be displayed in the new size. (To change the font size for another Data Type, repeat step two above.) 3. To return to the previous page, press EXIT.
Sonar chart with Overlay Data turned on. This example shows Depth, Water Temperature and the Water Speed of the boat.
Ping Speed & HyperScroll
Ping Speed controls the rate at which the transmitter and transducer broadcast sonar sound waves pings into the water. The unit has a default ping speed of 50 percent. At normal boating speeds, this automatically provides enough return echoes to refresh the screen and scroll the chart at maximum chart speed. However, when you are running at high speeds, or just want the fastest possible screen update, you may want to use the HyperScroll feature. When you change the Ping Speed to any setting greater than 50 percent, the unit automatically enters HyperScroll mode. These faster ping rates allow you to maintain a high-detail picture on the screen, and the screen refresh rate and chart scroll speed can keep pace with the boat as it moves quickly over the bottom terrain. When using HyperScroll, you may also need to manually decrease the sensitivity for optimum performance. Depending on water depth and other conditions, HyperScroll may cause a second bottom echo to return to the transducer during the next ping cycle, or sounding. This can result in a large amount of clutter appearing on the screen. If this occurs, just decrease the sensitivity to a level that eliminates the clutter. When you turn HyperScroll off, you can return to your original sensitivity level.

You can customize other digital data windows before returning to the Sonar Page. After changing the first window by selecting the Data Type and pressing Enter, use the key to select another window to change. When the selected window title bar flashes, press ENT| or to select data type|ENT. Repeat these steps until you're finished customizing, then press EXIT to return to the Sonar Page. 71
Options List for customizing Digital Data windows.
FlashGraf The FlashGraf sonar page option represents a flasher style sonar combined with a scrolling chart. A circular dial shows all returning echoes at a high screen refresh rate. It uses the Colorline feature to distinguish between strong and weak signals. For example, fish, one of the weakest echoes, shows up as a narrow blue line, while a hard bottom surface will be a thick yellow band. The bottom depth is shown as a black bar across the outer circle. There is also a narrow chart display on the left of the screen.

Surface clutter

Fish signal, approximately 16 feet
Bottom signal FlashGraf page.

Sonar Simulator

This unit has a built-in simulator that lets you run it as if you were on the water. All sonar features and functions are useable. When in simulator mode, you will see [Simulated] at the bottom of the display. To use the simulator: 72
1. From the Sonar Page, press MENU|MENU| to SONAR SIMULATOR|ENT. 2. Turn off Sonar Simulator by pressing MENU|MENU| to SONAR SIMULATOR|ENT|EXIT. NOTE: If you turn on your unit before attaching a transducer, it may enter a demo mode. The words "demo mode" flash on the bottom of the screen and a sonar chart plays much like the simulator. Unlike the simulator, the demo mode is for demonstration only, and will automatically stop as soon as you turn on the unit with a transducer attached. The simulator will continue to function normally.

Stop Chart

If you are running multiple units on a boat, there are times when you may want to turn off the sonar. This command turns off the sonar and stops the chart from scrolling. Sonar restarts automatically each time you turn on your unit. Press MENU| to STOP CHART|ENT|EXIT. To turn on sonar and start the chart scrolling again, repeat the above step.