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Lowrance X125 Operation Instructions Manual

Fish-finding & depth sounding sonars.
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Pub. 988-0151-171
X125, X126DF, X135, X136DF
Fish-finding & Depth Sounding Sonars
Operation Instructions


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   Summary of Contents for Lowrance X125

  • Page 1

    Pub. 988-0151-171 X125, X126DF, X135, X136DF Fish-finding & Depth Sounding Sonars Operation Instructions...

  • Page 2

    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.

  • Page 3: 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 ...

  • Page 4

    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...

  • Page 5: Sec. 1: Read Me First

    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.

  • Page 6: Capabilities And Specifications: X125, X126df, X135, X136df

    X126DF and X136DF. It has 35°/12° cone angles. A single-frequency with built-in tem- perature sensor is packed with the X125 and X135. It has a 20° cone angle. Transducers operate at speeds up to 70 mph (61 kts).

  • Page 7: How Sonar Works

    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.

  • Page 8: How To Use This Manual: Typographical Conventions

    The receiver amplifies this return signal, or echo, and sends it to the display, where an image of the object appears on the scrolling sonar chart. The sonar's microprocessor calculates the time lapse between the transmitted signal and echo return to determine the distance to the object.

  • Page 9

    Instructions = Menu Sequences Most functions you perform with the sonar unit are described as a se- quence 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.

  • Page 10


  • Page 11: Sec. 2: Installation & Accessories

    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 drill- ing any holes in your vessel! 1.

  • Page 12: Recommended Tools And Supplies

    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.

  • Page 13: How Low Should You Go

    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.

  • Page 14: Shoot-thru-hull Vs. Transom Mounting

    quently lose bottom signal lock while running at high speed, the trans- ducer may be coming out of the water as you cross waves or wakes. Move the transducer a little lower to help prevent this. If you cruise or fish around lots of structure and cover, your transducer may be frequently kicking up from object strikes.

  • Page 15

    Align plastic ratchets in bracket. B. Two-piece bracket: Locate the four plastic ratchets in the trans- ducer's hardware package. Press two ratchets into the sides of the plas- tic bracket and two on either side of the transducer as shown in the fol- lowing illustrations.

  • Page 16

    Transducer Transducer bracket Ratchet Ratchet Add ratchets to bracket and transducer. 2. Aligning the transducer on the transom. A. One-piece bracket: Slide the transducer between the two ratch- ets. Temporarily slide the bolt though the transducer assembly and hold it against the transom. Looking at the transducer from the side, check to see if it will adjust so that its face is parallel to the ground.

  • Page 17

    B. Two-piece bracket: Assemble the transducer and bracket as shown in the following figure. Temporarily slide the bolt though the transducer assembly but don't tighten the nut at this time. Hold the assembled transducer and bracket against the transom. Looking at the transducer from the side, check to see if it will adjust so that its face is parallel to the ground.

  • Page 18

    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.

  • Page 19

    Electrical noise from the engine's wiring, bilge pumps, VHF radio wires and cables, and aerators can be picked up by the sonar. Use cau- tion when routing the transducer cable around these wires.

  • Page 20: Trolling Motor Bracket Installation (single-frequency Only)

    (not included) to attach the transducer cable to the troll- ing 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 trans- ducer is ready for use.

  • Page 21: Transducer Orientation And Fish Arches

    The transducer installation inside a fiberglass hull must be in an area that does not have air bubbles in the resin or separated fiberglass lay- ers. The sonar signal must pass through solid fiberglass. A successful Partial fish arches Proper transducer angle...

  • Page 22

    Next, take the transducer out of the water and place it in the water in the sump of the boat. Observe the sonar signal to see if there is a no- ticeable decrease in sensitivity. The second bottom signal may disap- pear and the bottom signal may decrease in intensity.

  • Page 23: Shoot-thru-hull Installation

    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) 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.

  • Page 24: Speed/temperature Sensors

    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.

  • Page 25: Sensor Chart

    Sonar unit rear view Two-temperature sensor installation MY-4X Cable Three-temperature sensor installation Three-temperature sensor installation with speed Sensor Chart SP-X speed sensor Temperature sensor built into transducer TS-2X temperature sensor TS-3X temperature sensor...

  • Page 26: Optional Speed Sensor Installation

    Optional Speed Sensor Installation All the units in this series can display speed and distance traveled, but only the X126DF and X136DF come packed with a speed sensor. If you wish to purchase an optional additional sensor for your unit, refer to the accessory ordering information inside the back cover of this man- ual.

  • Page 27: Power Connections

    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".

  • Page 28

    However, the unit will not work until the wires are attached correctly. An optional 8-foot, CA-4 external power cable with a cigarette lighter adapter is available from Lowrance. Optional power off switch for saltwater installations Black wire...

  • Page 29: Mounting The Unit: Bracket, In-dash Or Portable

    Power wires 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.

  • Page 30

    (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.

  • Page 31

    [5.43] Front view (left) and side view (right) showing dimensions of the sonar unit when mounted on gimbal bracket. After drilling the hole, pass the transducer connector up through the hole from under the dash. Pass the power cable's bare-wire end down though the hole from the top.

  • Page 32: In-dash/portable Installation

    Portable Installation Like many Lowrance products, this sonar unit is capable of portable operation by using the optional PPP-11 portable power pack. The power pack and an optional portable transducer expand the uses for your so- nar unit.

  • Page 33: Face Cover

    "D" cell battery Install batteries in power pack battery adapter. Face Cover Your unit comes with a white protective cover that snaps on and off the front of the unit. This cover is intended for use when your unit and the vehicle it's mounted in are idle.

  • Page 34


  • Page 35: Sec. 3: Basic Sonar Operation

    Before you turn on the unit, it's a good idea to learn about the different keys, the Main Menu, the Sonar Menu, the five Page options and how they all work together. BUT, if you just can't wait to get on the water, turn to the one-page Quick Reference on page 38.

  • Page 36: Power/lights (turn Unit On And Off)

    3 seconds. Menus Your sonar unit will work fine right out of the box with the factory de- fault settings. You only need to learn a few basic functions to enhance your viewing. We'll discuss them briefly here, then talk about them and all the other commands in more detail in the next section, which begins on page 43.

  • Page 37

    • 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.

  • Page 38: Sonar Menu

    . 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.

  • Page 39: Pages

    • 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.

  • Page 40

    The Full Sonar Chart is the main display option. This is a "cross- section" 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. Digital data overlay (depth &...

  • Page 41

    You can customize how the Sonar Page pictures and other data are dis- played in many ways. We'll discuss all of those features and options in Section 4, but to show you how easy the sonar unit is to operate, the fol- lowing page contains a simplified, 10-step quick reference that will cover most fish finding situations.

  • Page 42: Basic Sonar Quick Reference

    The auto settings will track the bottom, displaying it in the lower por- tion of the screen. The full sonar chart will scroll from right to left, showing you what's under the boat as you cruise across the water.

  • Page 43: Sonar Operations

    As you can see from the quick reference on the previous page, basic operation is pretty easy, right out of the box. If you are a sonar novice, try operating the unit with the factory defaults until you get a feel for how it's working.

  • Page 44

    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 sensitiv- ity to 100 percent, but the unit will limit your minimum setting. This pre- vents you from turning sensitivity down too low to allow automatic bot- tom tracking.

  • Page 45: Fish Symbols Vs. Full Sonar Chart

    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.

  • Page 46: Other Free Training Aids

    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.

  • Page 47: Sec. 4: Sonar Options & Other Features

    Material in this section is arranged in alphabetical order. ASP (Advanced Signal Processing) The ASP feature is a noise rejection system built into the sonar unit that constantly evaluates the effects of boat speed, water conditions and interference. This automatic feature gives you the best display pos- sible under most conditions.

  • Page 48: Alarms

    Alarms This unit has three different types of sonar alarms. The first is the Fish Alarm. It sounds when the Fish I.D. feature determines that an echo is a fish. Another alarm is the Zone Alarm, which consists of a bar on the side of the screen.

  • Page 49: Zone Alarm

    5. To turn off the alarm, press To switch to a different depth setting, open the Sonar Alarms menu and repeat the instructions in step 3 above. To adjust and turn on the deep alarm: 1. Press LARM 2. Press ↓ to 3.

  • Page 50: Fish Alarm

    6. To turn off the alarm, press EXIT ABLED To switch to a different depth setting, open the Sonar Alarms menu and repeat the instructions in steps 3 and 4 above. Fish Alarm Use the fish alarm for a distinctive audible alarm when fish or other suspended objects are detected by the Fish I.D....

  • Page 51: Chart Speed

    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.

  • Page 52: Contrast

    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 pin- point the depth of a target.

  • Page 53: Depth Range - Manual

    You have complete control over the range when the unit is in the man- ual mode. There are 16 depth ranges, from 5 feet to 4,000 feet. To switch to Manual Depth Range: 1. First, turn off automatic depth range. From the Sonar Page, press |↓ to MENU EPTH 2.

  • Page 54

    This feature lets you "zoom in" the display in almost unlimited combinations. Nearly any segment of the water column, from the surface to the bottom can be shown. This enlarges the sonar targets to best suit your fishing needs and water conditions.

  • Page 55: Fastrack

    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.

  • Page 56

    Does that mean Fish I.D. is broken? No — the feature is simply inter- preting 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.

  • Page 57: Fishtrack

    At left, figures 1A and 2A show Sonar Page in normal chart mode. At right, figures 1B and 2B show the same underwater scene with Fish I.D. turned on. Note how arches are replaced with symbols.

  • Page 58: Fishreveal

    Sonar Features menu with Fish I.D. Depths selected (at left, dual- frequency menu; center, single-frequency menu). When the check box to the left is checked, the feature is on. At right, Sonar Page showing Fish I.D. symbols and FishTrack depths turned on.

  • Page 59

    Fish visible Fish arch 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.

  • Page 60: Frequency (change Transducer Frequency)

    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.

  • Page 61: Grayline

    Grayline is adjustable. Experiment with your unit to find the Grayline setting that's best for you. At left, Sonar Page menu with Grayline command selected. At right, the Grayline control bar. To adjust the Grayline level: 1.

  • Page 62

    Fig. 1A Fig. 2A Fig. 3A This series of figures shows how different Grayline settings can reveal more information. The "A" figures to the left show locations with Gray- line set at the factory level of 64 percent. At right, the "B" figures show the same locations with Grayline increased to 84 percent.

  • Page 63: 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 |↓ to MENU VERLAY 2.

  • Page 64: To Change Displayed Data Font Size

    Size| The data will be shown in the new font size. To return to the previ- ous page, press Sonar chart with Overlay Data turned on. This example shows Depth, Water Temperature and the Water Speed of the boat. VERLAY...

  • Page 65: Ping Speed & Hyperscroll

    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 auto- matically provides enough return echoes to refresh the screen and scroll the chart at maximum chart speed.

  • Page 66: Pop-up Help

    FasTrack bar graph display doubles in width at the right side of the screen. The allows you to better see the virtually instantaneous sonar returns, just as you would on a flasher sonar unit. For more informa- tion on FasTrack, see it's entry in this section.

  • Page 67: Reset Options

    Reset Options dialog box, with "Yes" selected. Reset Water Distance The sonar chart's Digital Data display option includes a window that shows distance traveled, called Water Distance ("W Distance"). This information is calculated from an optional water speed sensor. The Wa- ter Distance window can be reset to zero using the Reset Water Dis- tance command.

  • Page 68: Sensitivity & Auto Sensitivity

    Screen Command, left, and Screen Menu with Contrast bar selected, right. To adjust the display's brightness: Press ↓ to . Press → or ← to move the bar. The left end of the RIGHTNESS scale is minimum contrast; the right end is maximum contrast. To adjust the screen's display mode: Press ↓...

  • Page 69

    ↑ to increase sensitivity. When it's set at the desired level, press . (When you reach the maximum or minimum limit, a tone sounds.) EXIT At left, Sonar Menu with Sensitivity command selected. At right, the Sensitivity Control Bar.

  • Page 70: To Turn Auto Sensitivity Back On

    To adjust sensitivity in manual mode: 1. First, turn off Auto Sensitivity: from the Sonar Page, press ENSITIVITY 2. Press ↑ to ENSITIVITY Press ↓ or ↑ to pick a different sensitivity setting. When it's set at the desired level, press...

  • Page 71: Set Language

    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,

  • Page 72: Sonar Chart Mode

    3. To return to the last page displayed, press 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.

  • Page 73: Full Sonar Chart

    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.) Full Sonar Chart. The Overlay Data (depth and water temperature) are both set to the small text size.

  • Page 74: Split Zoom Sonar Chart

    The zoom range shows at the bottom left corner of the screen. Split Zoom Sonar Chart. Image at left shows the left window zoomed to 2X. The right image shows the left window zoomed to 4X. The depth overlay data is set to the default large text size;...

  • Page 75: Digital Data/chart

    ↑ to increase sensitivity. When it's set at the desired level, press . (When you reach the maximum or minimum limit, a tone sounds.) EXIT The Split Frequency Sonar Chart page allows you to adjust sensitivity separately for each window. Digital Data/Chart This mode shows the chart on the right side of the screen.

  • Page 76: Customizing The Digital Data/chart Screen

    1. From the Sonar Page (in Digital Data mode), press USTOMIZE At left, the Customize command selected from the Sonar Page menu. At right, the selected W Speed box flashes black. 2. The W Speed window title bar flashes, indicating the window con- tents can be changed.

  • Page 77: Flashgraf

    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 [Simulator Mode] in the Sonar Page title bar. To use the simulator: 1.

  • Page 78: Stop Chart

    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.

  • Page 79: Transducer Type (x126df And X136df Only)

    Sonar Features menu with Surface Clarity selected (at left, dual- frequency menu; at right, single-frequency menu). 2. Press ↓ to URFACE 3. Press ↓ or ↑ to select clarity level| Surface clutter In the illustration at left, Surface Clarity is turned off.

  • Page 80: Units Of Measure

    At left, Main Menu showing Transducer Type command selected. At right, the Transducer Type menu, showing your three options. Units of Measure This menu sets the speed and distance (statute or nautical miles, me- ters), depth (feet, fathoms, or meters) and temperature (degrees Fahr- enheit or Celsius).

  • Page 81: Zoom Pan

    Press the Zoom Out key, , to return the display to the normal mode. ZOUT At left, Sonar Page, normal view. Center, same view zoomed to 2X. Right, same view zoomed to 4X Zoom Pan Your unit has the handy ability to quickly zoom in on any portion of the water column with just the touch of an arrow key.

  • Page 82


  • Page 83: Sec. 5: Sonar Troubleshooting

    Unit freezes, locks up, or operates erratically: 1. Electrical noise from the boat's motor, trolling motor, or an accessory may be interfering with the sonar unit. Rerouting the power and trans- ducer cables away from other electrical wiring on the boat may help.

  • Page 84

    1. The transducer may be in turbulent water. It must be mounted in a smooth flow of water in order for the sonar to work at all boat speeds. Air bubbles in the water disrupt the sonar signals, interfering with its ability to find the bottom or other targets.

  • Page 85

    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.

  • Page 86


  • Page 87

    Accessories, 1, 25, 26 Sec. 2, Installation & Accessories, 7 Alarms, 33, 44, 45, 46 Depth Alarms, 44 Fish Alarm, 44, 46 Zone Alarm, 44, 45, 46 Antenna, 81 ASP (Advanced Signal Processing), 18, 43 Backlights / Lighting, 2, 31 Batteries, 7, 23, 24, 28, 29, 79, 80, 81 Brightness, 33, 46, 48, 63, 64 Calibrate Speed, 46...

  • Page 88

    Sonar Chart Color Mode, 55, 68 FishReveal, 54 Sonar Chart Display Options, 31, 35, 36, 37, 68, 69, 70, 71, 72, 73 Sonar Menu, 31, 32, 34, 40, 43, 59, 61, 65, 74 Sonar Operation Quick Reference, 38 Speed Sensors, 3, 20, 22, 33, 46, 63, 71...

  • Page 89: Sec. 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.

  • Page 90: How To Obtain Service

    …in the USA: We back your investment in quality products with quick, expert service and genuine Lowrance parts. If you're in the United States and you have technical, return or repair questions, please contact the Factory Customer Service Department. Before any product can be returned, you must call customer service to determine if a return is necessary.

  • Page 91

    To locate a Lowrance dealer near you, visit our web site, and look for the Dealer Locator. Or, you can consult your telephone directory for listings.

  • Page 92

    Visit our web site: Lowrance Pub. 988-0151-171 © Copyright 2003 All Rights Reserved Printed in USA 111903 Lowrance Electronics...

This manual also for:

X126df, X135, X136df

Comments to this Manuals

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Latest comments:
  • Theresa slone May 16, 2016 09:54:
    Purchased boat with Lowrance x125 fish finder. Need operation manual
  • B Vasel Jun 01, 2014 02:18:
    Thanks for the manual, I just purchase a boat with the lowrance x125 and need you help with a manual to poperate it.