Pub. 988-0151-171 www.lowrance.com
X125, X126DF, X135, X136DF
Fish-finding & Depth Sounding Sonars

Operation Instructions

Copyright 2003 Lowrance Electronics, Inc. All rights reserved. Lowrance is a registered trademark of Lowrance Electronics, Inc. Navionics is a registered trademark of Navionics, Inc.
Lowrance Electronics may find it necessary to change or end our policies, regulations and special offers at any time. We reserve the right to do so without notice. All features and specifications subject to change without notice. All screens in this manual are simulated. On the cover: X136DF shown. Other models covered in the manual are similar.
For free owner's manuals and other information, visit our web site:

www.lowrance.com

Lowrance Electronics Inc. 12000 E. Skelly Dr. Tulsa, OK USA 74128-2486

Table of Contents

Sec. 1: Read Me First!... 1 Capabilities and Specifications: X125, X126DF, X135, X136DF. 2 How Sonar Works... 3 How to Use this Manual: Typographical Conventions. 4 Sec. 2: Installation & Accessories.. 7 Preparations.... 7 Transducer Installation... 7 Recommended Tools and Supplies.. 8 Selecting a Transducer Location.. 8 How Low Should You Go?.. 9 Shoot-Thru-Hull vs. Transom Mounting.. 10 Transom Transducer Assembly and Mounting.. 10 Trolling Motor Bracket Installation (Single-Frequency only). 16 Transducer Orientation and Fish Arches.. 17 Shoot-Thru-Hull Preparation and Installation.. 17 Speed/Temperature Sensors.. 20 Sensor Chart... 21 Optional Speed Sensor Installation.. 22 Power Connections... 23 Mounting the Unit: Bracket, In-Dash or Portable.. 25 Face Cover... 29 Sec. 3: Basic Sonar Operation.. 31 Keyboard... 31 Power/Lights (Turn Unit On and Off).. 32 Menus... 32 Main Menu... 32 Sonar Menu.... 34 Pages... 35 Basic Sonar Quick Reference.. 38 Sonar Operations.. 39 Fish Symbols vs. Full Sonar Chart.. 41 Other Free Training Aids.. 42 Sec. 4: Sonar Options & Other Features.. 43 ASP (Advanced Signal Processing)... 43 Alarms.... 44 Depth Alarms... 44 Zone Alarm... 45 Fish Alarm... 46 Brightness... 46 Calibrate Speed... 46 Chart Speed... 47 Contrast.... 48 i
Depth Cursor... 48 Depth Range - Automatic... 48 Depth Range - Manual... 49 To Turn Auto Depth Range on Again:.. 49 Depth Range - Upper and Lower Limits.. 49 FasTrack.... 51 Fish I.D. (Fish Symbols & Depths)... 51 FishTrack... 53 FishReveal... 54 Frequency (Change Transducer Frequency).. 56 Grayline... 57 HyperScroll... 59 Noise Rejection... 59 Overlay Data... 59 To Change Displayed Data Font Size:.. 60 Ping Speed & HyperScroll.. 61 Pop-Up Help... 62 Reset Options... 63 Reset Water Distance... 63 Screen Contrast and Brightness.. 63 Sensitivity & Auto Sensitivity.. 64 To Turn Auto Sensitivity Back on:... 66 Set Keel Offset... 66 Set Language... 67 Software Version Information.. 67 Sonar Chart Mode... 68 Sonar Chart Display Options... 68 Full Sonar Chart... 69 Split Zoom Sonar Chart... 70 Split Frequency Sonar Chart (X126DF and X136DF only). 70 Digital Data/Chart... 71 Customizing the Digital Data/Chart Screen.. 72 Flashgraf... 73 Sonar Simulator... 73 Stop Chart... 74 Surface Clarity... 74 Transducer Type (X126DF and X136DF only). 75 Units of Measure... 76 Upper and Lower Limits.. 76 Zoom & Zoom Bar... 76 Zoom Pan... 77 Sec. 5: Sonar Troubleshooting... 79 Sec. 6: Supplemental Material... 85 ii
How this manual can get you out on the water, fast!
Welcome to the exciting world of digital sonar! We know you're anxious to begin finding fish, but we have a favor to ask. Before you grab your unit and begin installing it, please give us a moment or two to explain how our manual can help you get the best performance from your compact, wide-screen, fish finder. First, we want to thank you for buying a Lowrance sonar. Whether you're a first time user or a professional fisherman, you'll discover that your unit is easy to use, yet capable of handling demanding sonar tasks. You won't find another sonar unit with this much power and this many features for this price! Our goal for this book is to get you on the water fast, with a minimum of fuss. Like you, we'd rather spend more time boating or fishing and less time reading the manual! So, we designed our book so that you don't have to read the whole thing from front to back for the information you want. At the start (or end) of each segment, we'll tell you what content is coming up next. If it's a concept you're already familiar with, we'll show you how and where to skip ahead for the next important topic. We've also made it easy to look up any tips you may need from time to time. Here's how: The manual is organized into 6 sections. This first section is an introduction to the sonar unit. It tells you the basics you need to know before you can make the unit look below the surface to find some fish. Section 2 will help you install your unit and the transducer. We'll also tell you about some of the available accessories. Section 3 covers Basic Sonar Operation. It will show you how easy it is to run your sonar, right out of the box. This section features a one-page Sonar Quick Reference. (If you've already jumped ahead and figured out how to install the unit yourself, and you just can't wait any longer, turn to the Quick Reference on page 38 and head for the water with your sonar unit!) After you've gained some experience with your sonar, you'll want to check out Section 4, which discusses more advanced Sonar Options and Other Features. When you come to a sonar menu command on the unit's screen, you can look it up in the manual by skimming over the table of contents or index, just flipping through Section 3 or scanning through the sonar options in Section 4. 1

Instructions = Menu Sequences Most functions you perform with the sonar unit are described as a sequence of key strokes and selecting menu commands. We've written them in a condensed manner for quick and easy reading. For example, instructions for turning on the Fish ID feature would look like this: 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press to FISH SYMBOLS|ENT|EXIT|EXIT. Translated into complete English, step 1 above would mean: "Start on the Sonar Page. Press the Menu key then repeatedly press (or press and hold) the down arrow key to scroll down the menu and select (highlight) the Sonar Features menu command. Then press the Enter key." Step 2 would mean: "Press the right arrow key to select (highlight) the Fish ID symbols command. Next, press the Enter key, then press the Exit key twice."
Section 2: Installation & Accessories

Preparations

You can install the sonar system in some other order if you prefer, but we recommend this installation sequence: Caution: You should read over this entire installation section before drilling any holes in your vessel! 1. Determine the approximate location for the sonar unit, so you can plan how and where to route the cables for the transducer and power. This will help you make sure you have enough cable length for the desired configuration. 2. Determine the approximate location for the transducer and its cable route. 3. Determine the location of your battery or other power connection, along with the power cable route. 4. Install the transducer and route the transducer cable to the sonar unit. 5. Install the power cable and route it to the sonar unit. 6. Mount the sonar unit.

Transducer Installation

These instructions will help you install your Skimmer transducer on a transom, on a trolling motor or inside a hull. These instructions cover both single- and dual-frequency Skimmer transducers. Please read all instructions before proceeding with any installation. The smaller single-frequency Skimmers typically use a one-piece, stainless steel mounting bracket. The larger dual-frequency Skimmers typically use a two-piece, plastic mounting bracket. The trolling motor mount uses a one-piece plastic bracket with an adjustable strap. These are all "kick-up" mounting brackets. They help prevent damage if the transducer strikes an object while the boat is moving. If the transducer does "kick-up," the bracket can easily be pushed back into place without tools. Read these instructions carefully before attempting the installation. Determine which of the mounting positions is right for your boat. Use 7

extreme care if mounting the transducer inside the hull, because once it is epoxied into position, the transducer usually cannot be removed. Remember, the transducer installation is the most critical part of a sonar installation. Recommended Tools and supplies If you prefer the option of routing the cable through the transom, you will need a 1" drill bit. A transom mount requires use of a high quality, marine grade above- or below-waterline caulking compound. The following installation types also call for these recommended tools and required supplies (supplies are not included):
Single-frequency transom installations
Tools include: two adjustable wrenches, drill, #29 (0.136") drill bit, flathead screwdriver. Supplies: none.
Dual-frequency transom installations
Tools: two adjustable wrenches, drill, #20 (0.161") drill bit, flat-head screwdriver. Supplies: four, 1" long, #12 stainless steel slotted wood screws.
Single-frequency trolling motor installations
Tools: two adjustable wrenches, flat-head screwdriver. Supplies: plastic cable ties.
Shoot-through hull installations
Tools: these will vary depending on your hull's composition. Consult your boat dealer or manufacturer. Supplies: 100 grit sandpaper, good quality epoxy adhesive. Selecting a Transducer Location 1. The transducer must be placed in a location that has a smooth flow of water at all times. If the transducer is to be mounted inside the hull, then the chosen location must be in the water at all times. If the transducer is not placed in a smooth flow of water, interference caused by bubbles and turbulence will show on the sonar's display in the form of random lines or dots whenever the boat is moving. NOTE: Some aluminum boats with strakes or ribs on the outside of the hull create large amounts of turbulence at high speed. These boats typically have large outboard motors capable of propelling the boat at speeds faster than 35 mph. Typically, a good location on aluminum boats is between the ribs closest to the engine. 2. The transducer should be installed with its face pointing straight down, if possible. 8
3. If the transducer is mounted on the transom, make sure it doesn't interfere with the trailer or hauling of the boat. Also, don't mount it closer than approximately one foot from the engine's lower unit. This will prevent cavitation (bubble) interference with propeller operation. 4. If possible, route the transducer cable away from other wiring on the boat. Electrical noise from engine wiring, bilge pumps and aerators can be displayed on the sonar's screen. Use caution when routing the transducer cable around these wires.

cation that shot through the hull the best and follow the instructions on the following pages for a shoot-thru-hull mounting.
Transducer location (high speed) Transducer location (trolling speed)
Shoot-thru-hull transducer locations for high speed or trolling speed operation.
Shoot-thru-hull Installation 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 surface of the hull must be flat so the entire transducer face is in contact with the hull prior to bonding.

Spread epoxy here

Sand this surface
Epoxy transducer to hull.
2. Follow the instructions on the epoxy package and mix it thoroughly. Do not mix it too fast, because it will cause bubbles to form in the epoxy. Apply a small amount on the face of the transducer as shown above, then spread a small amount onto the sanded area on the hull. 19
Place the transducer into the epoxy, twisting and turning it to force any air bubbles out from under the transducer face. The face of the transducer should be parallel with the hull, with a minimum amount of epoxy between the hull and transducer. After the epoxy dries, route the cable to the sonar unit.
Speed/Temperature Sensors
This unit accepts up to three temperature sensors which can monitor surface water, live well, bait well and virtually any other temperature. If you want to use more than one temperature sensor or a speed sensor, you must purchase the optional MY-4X adapter cable. You also need to be careful when purchasing the temperature sensors, because each temperature sensor has its own fixed electronic "address." The sensors are labeled "Water," "T-2" (or Temp-2) and "T-3" (or Temp-3). The first "Water" temperature sensor is built into the transducer. This is the sensor that measures surface water temperature. If you want two (or more) temperature readings from other locations, you'll need to use the proper sensors. For example, you can't use two additional T-3 sensors. The sensors that fit this unit are: TS-1X This sensor will over-ride the temperature sensor built into the transducer and over-ride the temperature sensor in a ST-TGY combination sensor. (This sensor is not recommended.) One sensor for "T-2" temperature display. One sensor for "T-3" temperature display. One speed sensor for "Speed" display. This combination sensor will provide speed and temperature readings, but the temperature reading will be displayed as the "Water" temperature because it will over-ride the temperature sensor in the transducer. (This sensor is not recommended.)

TS-2X TS-3X SP-X ST-TGY

See the wiring diagram on the following page for temperature and speed sensor combinations.

Sensor Chart

Sonar unit rear view

Power Connections

The unit works from a 12-volt battery system. For the best results, attach the power cable directly to the battery. You can attach the power cable to an accessory or power buss, however you may have problems with electrical interference. Therefore, it's safer to go ahead and attach the power cable directly to the battery. CAUTION: When using the unit in a saltwater environment, we strongly recommend that you shut off the power supply to the power cable when the unit is not in use. When the unit is turned off but still connected to a power supply, electrolysis can occur in the power cable plug. This may result in corrosion of the plug body along with the electrical contacts in the cable and the unit's power socket. In saltwater environments we recommend you connect the power cable to the auxiliary power switch included in most boat designs. If that results in electrical interference, or if such a switch is not available, we recommend connecting direct to the battery and installing an inline switch. This will let you shut off power to the power cable when the unit is not in use. When you are not using the unit, you should always shut off power to the power cable, especially when the power cable is disconnected from the unit. If possible, keep the power cable away from other boat wiring, especially the engine's wires. This will provide the best isolation from electrical noise. If the cable is not long enough, splice #18 gauge wire onto it. The power cable has two wires, red and black. Red is the positive 23
lead, black is negative or ground. Make sure to attach the in-line fuse holder to the red lead as close to the power source as possible. For example, if you have to extend the power cable to the battery or power buss, attach one end of the fuse holder directly to the battery or power buss. This will protect both the unit and the power cable in the event of a short. It uses a 3-amp fuse.
Optional power off switch for saltwater installations To unit

You can change the sensitivity level whether you are in Auto Sensitivity mode or Manual Sensitivity mode. The adjustment method works the same in both modes, but it gives you slightly different results. Adjusting sensitivity in Auto Sensitivity Mode is similar to manually adjusting a car's speed with the accelerator pedal while cruise control is on. You can tell the car to run faster, but when you let off the gas the cruise control automatically keeps you from running slower than the minimum speed setting. In the sonar unit, auto mode will let you increase sensitivity to 100 percent, but the unit will limit your minimum setting. This prevents you from turning sensitivity down too low to allow automatic bottom tracking. When you change the setting with auto turned on, the unit will continue to track the bottom and make minor adjustments to the sensitivity level, with a bias toward the setting you selected. Adjusting sensitivity in Manual Sensitivity Mode is similar to driving a car without cruise control you have complete manual control of the car's speed. In the sonar unit, manual mode allows you to set sensitivity at 100 percent (maximum) or zero percent (minimum.) Depending on water conditions, the bottom signal may completely disappear from the screen when you reduce sensitivity to about 50 percent or less! Try adjusting sensitivity in both auto and manual modes to see how they work. To adjust sensitivity: 1. Press MENU|ENT. 2. The Sensitivity Control Bar appears. Press to decrease sensitivity; press to increase sensitivity. When it's set at the desired level, press EXIT. (When you reach the maximum or minimum limit, a tone sounds.)
At left, Sonar Menu with Sensitivity command selected. At 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. 41

Chart Speed

The rate that echoes scroll across the screen is called the chart speed. The default is maximum; we recommend that you leave the speed set there for virtually all fishing conditions. However, you might consider experimenting with chart speed when you are stationary or drifting very slowly. You may sometimes achieve better images as you slow down the chart speed to match how fast you are moving across the bottom. If you are at anchor, ice fishing or fishing from a dock, experiment with a chart speed around 50 percent. If you are drifting slowly, try a chart speed around 75 percent. When you are stationary and a fish swims through the sonar signal cone, the image appears on the screen as a long line instead of a fish arch. Reducing the chart speed may result in a shorter line that more closely resembles a regular fish return.
At left, Sonar Page menu with Chart Speed command selected. At right, Chart Speed Control Bar.
If you do experiment with chart speed, remember to reset it to maximum when you resume trolling or moving across the water at higher speed. To change chart speed: 1. From the Sonar Page, press MENU| to CHART SPEED|ENT. 2. The Chart Speed Control Bar appears. Press to decrease chart 47
speed; press to increase chart speed. 3. When it's set at the desired level, press EXIT.

Contrast

Depth Cursor
The depth cursor consists of a horizontal line with a digital depth box on the right side. The numbers inside the box show the depth of the cursor.

Cursor line Depth box

At left, Sonar Page menu with Depth Cursor command selected. At right, sonar chart with the depth cursor active. The line indicates the large fish is 34.64 feet deep.
The cursor can be moved to any location on the screen, letting you pinpoint the depth of a target. 1. From the Sonar Page, press MENU| to DEPTH CURSOR|ENT. 2. The depth cursor appears. Press to lower the cursor line; press to raise the cursor line. 3. To clear the depth cursor, press EXIT.

Depth Range - Automatic

When turned on for the first time, the bottom signal is automatically placed in the lower half of the screen. This is called Auto Ranging and is part of the automatic function. However, depending upon the bottom depth and the current range, you can change the range to a different depth. To do this: 48
1. From the Sonar Page, press MENU| to DEPTH RANGE|ENT.
At left, Sonar Page menu with Depth Range command selected. At right, the Depth Range Control Scale.
2. The Depth Range Control Scale appears. Press or to select a different depth range. a black bar highlights the selected range. Range numbers in gray cannot be selected. 3. When the new range is selected, press EXIT to clear the menu.

Depth Range - Manual

You have complete control over the range when the unit is in the manual mode. There are 16 depth ranges, from 5 feet to 4,000 feet.

Surface clutter Fish arches Structure In FasTrack, fish arches show as horizontal bars.
Grayline 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. 51
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 (at left, dualfrequency menu; at right, single-frequency menu). When the check box to the left is checked, the feature is on.

Sonar Chart Mode command with FishReveal selected (at left, dual-frequency menu; at right, single-frequency menu).
To turn FishReveal on: 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press |then press to SONAR CHART MODE|ENT| to FISHREVEAL|ENT. 3. Press EXIT| to AUTO SENSITIVITY|ENT| to SENSITIVITY|ENT. 4. Press until the Sensitivity Control Bar reads 100% (or close to it), then press EXIT. (If you reach the maximum limit, a tone sounds.)
Fish not visible Fish arch

Visible fish

Fish arches Sonar chart in regular grayscale mode, left, and in FishReveal mode, right. Notice how shallow fish formerly hidden in the surface clutter become visible in FishReveal mode.
NOTE: Water conditions vary greatly, and that affects sonar performance. Under certain conditions, FishReveal will show you more fish than normal grayscale mode, but the reverse will be true in other circumstances. We suggest you become familiar with both modes so you can best match your sonar's performance to the current water conditions. 55
Frequency (Change Transducer Frequency) (X126DF and X136DF 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 salt water sport fishing applications. When you get into very deep salt water, 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 salt water.) There is a common exception to these rules of thumb. Some fishermen on freshwater lakes (or the ocean) using downriggers like to see them on the sonar. In many of those cases, you'll see a 50 kHz transducer frequency in use because the wider cone angle lets them watch the bait.
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 adjust sensitivity in manual mode: 1. First, turn off Auto Sensitivity: from the Sonar Page, press MENU| to AUTO SENSITIVITY|ENT. 2. Press to SENSITIVITY|ENT and the Sensitivity Control Bar appears. Press or to pick a different sensitivity setting. When it's set at the desired level, press EXIT. To turn Auto Sensitivity back on: From the Sonar Page, press MENU| to AUTO SENSITIVITY|ENT|EXIT. NOTE: To return to the original factory setting for Auto Sensitivity, see the entry in this section on Reset Options. If sensitivity is in manual mode, the Reset Options command will switch back to Auto and reset the factory setting at the same time.
For quicker sensitivity adjustments, try leaving the Sensitivity Control Bar on the screen as the chart scrolls. You can see the changes on the screen as you press the up or down arrows. This is handy when there's a lot of clutter in the water, and you are matching the sensitivity to rapidly changing water conditions.

Set Keel Offset

This unit measures water depth from the face of the transducer. Since the transducer is installed below the water surface, the distance displayed by the digital depth, chart depth scale, chart cursor or fish symbols is not the exact water depth. If the transducer is 1 foot below the surface, and the screen shows the water depth as 30 feet, then the actual depth is 31 feet. On sailboats or other large vessels with deep drafts, the distance between the transducer installation and the keel or lower engine unit can be several feet. In those cases, an inexact depth reading could result in grounding or striking underwater structure. The Keel Offset feature eliminates the need for the navigator to mentally calculate how much water is under his keel. Keel Offset lets you calibrate the digital depth: chart depth scale, chart cursor depth and fish symbol depth displayed on the screen. To calibrate the depth indicators, first measure the distance from the face of the transducer to the lowest part of the boat. In this example, we will use 3.5 feet. We enter this as a negative 3.5 feet, which makes the depth indicators perform as if the transducer's lower in the water than it really is. 66
1. Press MENU|MENU| to SET KEEL OFFSET|ENT. 2. The Keel Offset dialog box appears. Press to change the plus (+) sign to a minus () sign. 3. Press to the first number, then press to change the number to 3 4. Press to the second number, then press to change the number to 5, then press EXIT. The depth indicators now accurately show the depth of water beneath the keel. NOTE: If knowing the exact depth of water beneath the keel is less important, you can calibrate the depth indicators so that they show the actual water depth from surface to bottom. To do this, first measure the distance from the face of the transducer up to the surface (the water line on the boat). In this example, we will use 1.5 feet. This will be entered as a positive 1.5 feet, which makes the depth indicators perform as if the transducer's higher in the water than it really is. 1. Press MENU|MENU| to SET KEEL OFFSET|ENT. 2. The Keel Offset dialog box appears with a plus (+) sign at the front of the box. 3. Press to the first number, then press to change the number to 1. 4. Press to the second number, them press to change the number to 5, then press EXIT. The depth indicators now accurately show the water depth from surface to bottom.

Set Language

This unit's menus are available in 10 languages: English, French, German, Spanish, Italian, Danish, Swedish, Russian, Dutch and Finnish. To select a different language: 1. Press MENU|MENU| to SET LANGUAGE|ENT. 2. Use or to select a different language and press ENT. All menus now appear in the language you selected.
Software Version Information
From time to time, Lowrance updates the operating system software in some of its products. These software upgrades are usually offered to customers as free downloads from our web site, www.lowrance.com. These upgrades make the unit perform better or introduce a new feature or function. You can find out what software version is running in your sonar unit by using the Software Information command. 67
At left, Main Menu with Software Information command selected. At right, the Software Information screen.
1. Press MENU|MENU| to SOFTWARE INFO|ENT. 2. Read the information displayed on the screen. 3. To return to the last page displayed, press EXIT|EXIT.

Sonar Chart Mode

The default color scheme for the sonar chart is grayscale, but we offer other variations to suit your viewing preferences. You can select the chart to be displayed in reverse grayscale, bottom black or FishReveal mode. (For more information on FishReveal, see the entry on that topic elsewhere in this section.) To change the chart mode color scheme: 1. From the Sonar Page, press MENU| to SONAR FEATURES|ENT. 2. Press to SONAR CHART MODE|ENT. 3. Press or to Mode Name|ENT. 4. Press EXIT|EXIT to return to the Sonar Page.
Sonar Chart Display Options
The Pages Menu offers five chart display options for dual-frequency models and four options for single-frequency models. To access them, press PAGES| to Option Name|EXIT.
Pages Menu showing sonar chart display options (at left, dual-frequency menu; at right, single-frequency menu).
Full Sonar Chart This is the default mode used when the unit is turned on for the first time or when it's reset to the factory defaults. The bottom signal scrolls across the screen from right to left. Depth scales on the right side of the screen aid in determining the depth of targets. The line at the top of the screen represents the surface. The bottom depth and surface temperature (if equipped with a temperature sensor or a transducer with a temp sensor built in) show at the top left corner of the screen. The FasTrack display shows just to the right of the scale. This changes all echoes into short horizontal bars, replicating a flasher sonar. The zoom bar on the far right shows the area that's zoomed when the zoom is in use. (See the Zoom section for more information.)

To eliminate or minimize the effects of electrical noise, first try to determine the cause. With the boat at rest in the water, the first thing you should do is turn all electrical equipment on the boat off. Make sure the engine is also off. Turn your sonar on, then turn off Noise Reject [also known as the ASP feature (Advanced Signal Processing)]. Sensitivity should be set at 90-95 percent. There should be a steady bottom signal on the display. Now turn on each piece of electrical equipment on the boat and view the effect on the sonar's display. For example, turn on the bilge pump and view the sonar display for noise. If no noise is present, turn the pump off, then turn on the VHF radio and transmit. Keep doing this until all electrical equipment has been turned on, their effect on the sonar display noted, then turned off. If you find noise interference from an electrical instrument, trolling motor, pump, or radio, try to isolate the problem. You can usually reroute the sonar unit's power cable and transducer cable away from the wiring that is causing the interference. VHF radio antenna cables radiate noise when transmitting, so be sure to keep the sonar's wires away from it. You may need to route the sonar unit's power cable directly to the battery to isolate it from other wiring on the boat. If no noise displays on the sonar unit from electrical equipment, then make sure everything except the sonar unit is turned off, then start the engine. Increase the RPM with the gearshift in neutral. If noise appears on the display, the problem could be one of three things; spark plugs, alternator, or tachometer wiring. Try using resistor spark plugs, alternator filters, or routing the sonar unit's power cable away from engine wiring. Again, routing the power cable directly to the battery helps eliminate noise problems. Make sure to use the in-line fuse supplied with the unit when wiring the power cable to the battery. When no noise appears on the sonar unit after all of the above tests, then the noise source is probably cavitation. Many novices or persons with limited experience make hasty sonar installations which function perfectly in shallow water, or when the boat is at rest. In nearly all cases, the cause of the malfunction will be the location and/or angle of the transducer. The face of the transducer must be placed in a location that has a smooth flow of water at all boat speeds. Read your transducer owner's manual or the Installation instructions (Sec. 2) in this manual for the best mounting position.

Units of Measure, 33, 76 Upper and Lower Limits, 35, 50, 76 Utilities, 31
Sensitivity, 34, 39, 40, 41, 54, 55, 62, 64, 65, 66, 71, 81 Simulator, 34, 73 Software Version Information, 67 Sonar Chart Color Mode, 55, 68 FishReveal, 54 Sonar Chart Display Options, 31, 35, 36, 37, 68, 69, 70, 71, 72, 73
Zooming, 3, 31, 32, 35, 38, 69, 70, 76, 77, 80 Zoom Bar, 76 Zoom Pan, 77
Section 6: Supplemental Material
LOWRANCE ELECTRONICS FULL ONE-YEAR WARRANTY
"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 consumer 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 (1) year from the date of original purchase by you. WE MAKE NO OTHER EXPRESS WARRANTY OR REPRESENTATION OF ANY KIND WHATSOEVER CONCERNING THIS PRODUCT. Your remedies under this warranty will be available so long as you can show in a reasonable 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 reasonable 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, OR REPLACEMENT OR REFUND (AS JUST DESCRIBED) IS THE EXCLUSIVE REMEDY AVAILABLE TO YOU AGAINST US FOR ANY DEFECT, MALFUNCTION, OR NON-CONFORMITY CONCERNING THE PRODUCT OR FOR ANY LOSS OR DAMAGE RESULTING FROM ANY OTHER CAUSE WHATSOEVER. WE WILL NOT UNDER ANY CIRCUMSTANCES BE LIABLE TO ANYONE FOR ANY SPECIAL, CONSEQUENTIAL, INCIDENTAL, OR OTHER INDIRECT DAMAGE OF ANY KIND. Some states do not allow the exclusion or limitation of incidental or consequential damages, 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 connected, installed, combined, altered, adjusted, or handled in a manner other than according 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 resulted from any accident, misuse, negligence, or carelessness, or from any failure to provide 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 original purchase in case warranty service is ever required.

Cable connections for Lowrance X135 and X136DF, March 25, 2004 Sockets with blue socket nuts, and cable plugs with blue locking collars are NMEA 2000 connection types. The network socket and optional NMEA 2000 buss adapter cable let the unit connect to a NMEA 2000 network. The NMEA 2000 Power cable gives you an option for powering the network. These units cannot transmit NMEA 0183 data and cannot connect to an external speaker. The NMEA 0183 data cable, the NMEA 2000 power cable (when unused) and the white speaker wire should be capped with wire nuts or electrical tape.
Sonar/GPS unit rear view Network socket

NETWORK

PWR/DATA
Sonar socket Blue Power/Data socket
NMEA 0183 Data cable. Four wires: blue, orange, yellow, shield (bare). Cable label says "RS-232 COMM." Not used in these units.
SP-BL speed sensor. This is packed with the X136DF and is optional for the X135.
Main Power Supply cable. Cable has no label, but is thickest of the three. Three wires: red (+), black ( ground), white. White is external speaker wire, not used in these units. NMEA 2000 Power cable. Three wires: red (+), black ( ground), shield (bare, ground). Cable label says "NMEA 2000 Power." Used when supplying power to a NMEA 2000 network. Optional NMEA 2000 buss adapter cable (network adapter cable)
Skimmer transducer with built-in temp sensor
To NMEA 2000 buss (network)
This figure corrects the drawings on pages 21 and 25 in the X135/X136DF manual, part 988-0151-171. It is a large-view supplement to the manual's Addendum I, part 988-0151-201.