| Operations Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   TABLE OF CONTENTS   INSTALLATION PREPARATION . . . . . . . . . . . . . . . . . . . . . . . 2   Parts Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2   Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2   Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . 2   Alternative Transducers and Mounting Methods. . . . . . 4   Transducer Exchange . . . . . . . . . . . . . . . . . . . . . . . . . 5   USING THE 250DX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6   How Sonar Works . . . . . . . . . . . . . . . . . . . . . . . . . . . 6   Simulator Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 7   What You See On Screen . . . . . . . . . . . . . . . . . . . . . . 8   Control Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . 11   Menu Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14   ADVANCED FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . 24   Using Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . 24   MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25   Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25   Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26   Customer Support . . . . . . . . . . . . . . . . . . . . . . . . . . 30   Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31   REV 10822E   Download from Www.Somanuals.com. All Manuals Search And Download.   INSTALLATION PREPARATION   PARTS SUPPLIED   PARTS SUPPLIED   Before installing your 250DX, please ensure the following parts are   included in the box:   • 250DX fishfinder   • Transducer with 6m (20') of cable and mounting hardware kit   • Mounting system and mounting hardware kit   • 6m (20') power cable   • Publications kit   If any of these items is missing, contact your local distributor .   ACCESSORIES   Humminbird offers a wide assortment of accessories that complement and   expand the capability of your new 250DX. These accessories are designed   with the same high standards and are backed by the same one-year   warranty. The Humminbird Accessory catalog included with your unit   contains descriptions of the many accessories available and ordering   information. All Humminbird accessories are available through your full-   service Humminbird dealer or factory direct through our number listed in   the Customer Support section.   INSTALLATION OVERVIEW   The 250DX consists of two primary components to install: the control head   and the transducer.   The control head contains the sonar transmit and receive circuitry, as well   as the user controls and display. It should be installed in a location that   provides access to the controls and visibility while in use. The control head   mounts on a quick disconnect mounting system that swivels and tilts   providing flexibility for viewing from almost anywhere on the boat.   The transducer converts electrical energy from the transmitter into   mechanical pulses or sound waves. The transducer also receives the   reflected sound waves and converts them back into electrical signals for   2 Download from Www.Somanuals.com. All Manuals Search And Download.   INSTALLATION PREPARATION   INSTALLATION OVERVIEW   display on the control head. It should be installed in contact with the   surface of the water in an area that has smooth water flow - usually on the   transom of the boat. There are several mounting options for the   transducer. Review the following section to determine the method that   works for you and your boat.   Determining How to Mount the Transducer   The 250DX includes a model XT-6-20   transducer. This transducer can be   mounted on the transom of the boat,   or bonded to the inside of a fiberglass   hull boat.   The transom installation, which is the   most widely used, places the transducer   on the outside of the boat hull. This   technique produces the least signal loss,   and provides a way to adjust the   transducer after installation. The   mounting hardware included is designed   to protect both the boat and the   Transom Mounted Transducer   transducer should the boat strike debris   in the water or when trailering.   As an alternative to transom   mounting, it is possible on many   fiberglass-hulled boats to glue the   transducer on the inside of the boat   hull. Since fiberglass has similar sonar   characteristics as water, the sonar   signal can pass through the boat hull   with minimal loss. The hull of the   boat must be single layer   construction (not double-hulled).   Also, any air trapped in the   lamination of the fiberglass would   prevent the sonar signal from passing   through.   Inside the Hull Mounted Transducer   Download from Www.Somanuals.com. All Manuals Search And Download.   3 INSTALLATION PREPARATION   ALTERNATE TRANSDUCERS AND MOUNTING METHODS   Inside the hull installations require no holes be drilled into the boat and   through experimentation, high-speed operation comparable to transom   mounting can be achieved. Two part, slow cure epoxy is required to glue   the transducer in place.   ALTERNATE TRANSDUCERS AND MOUNTING METHODS   The 250DX comes with everything necessary for installation and operation   on most boats. However, there are several situations which may require a   different type of transducer. Inboard boats, wood or metal hulls, and sail   boats create unique transducer mounting needs. Alternate transducers and   mounting methods are detailed below.   Portable Mounting   The standard transducer can be adapted for   portable installations using part number MHX-   PT2. This accessory adapts your transducer to a   suction cup mount for temporary installation on   the boat hull or other surface.   Trolling Motor Mounting   The standard transducer can also be adapted to   mount on most trolling motors using part   number AD-STM-7. This accessory includes a   bracket and hose clamp that allows mounting   the transducer to the body of most trolling   motors.   Thru-Hull Mounting   Thru-hull transducers install through a hole   drilled in the hull of the boat. Larger boats or   boats with inboard motors create turbulence   that make transom mounting ineffective. Also,   hulls that are very thick or are double layered, or   made from materials such as wood or metal,   4 Download from Www.Somanuals.com. All Manuals Search And Download.   INSTALLATION PREPARATION   TRANSDUCER EXCHANGE   (which do not conduct sonar signals) make inside the hull mounting   inadvisable.   Thru-hull mounting may require the use of a fairing block to level the   transducer with the waterline. Also, since special tools and knowledge may   be required to perform this type of installation it is best to refer to a   qualified marine technician.   TRANSDUCER EXCHANGE   Other transducers are available as replacements for the standard   transducer. You may exchange your new and unassembled transducer for   another type by returning it to the address listed in Customer Support.   Some transducers may have additional costs. Refer to the Accessory cata-   log or call Customer Support for information.   BEGINNING INSTALLATION   Now that you have determined the transducer mounting method, you can   begin installation of the 250DX. The fold out installation guide included   provides detailed step by step instructions for installation of the control   head and transducer. For transom mount transducer installations, you will   need the mounting template at the front of this manual.   In addition to the parts included you need the following for installation   and operation:   • A powered hand drill and various drill bits   • Phillips and flat-head screw drivers   • A ruler or measuring tape   • Pen or pencil   • 12 volt power source (your boat’s battery)   • A 1-amp fuse   • A fuse holder (if you are wiring directly to the boat’s battery)   • Silicone sealant (for sealing drilled holes)   • 2-part, slow-cure epoxy (for inside the hull transducer installations)   5 Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   HOW SONAR WORKS   HOW SONAR WORKS   Your Humminbird unit uses sonar to   locate and define underwater objects,   define the bottom terrain, as well as   determine distance.   Sonar technology is based on sound   waves. Your Humminbird unit sends   out a sound wave signal. With this   signal it determines distance by   measuring the time between the   transmission of the sound wave and   when the sound wave is reflected off   an object. Your Humminbird uses the   reflected signal to interpret location,   size and composition of an object.   Sonar is very fast. A sound wave can travel from the surface to a depth of   240' (70m) and back again in less than ¹⁄₄ of a second. It is unlikely that   your boat can "outrun" this sonar signal.   The 250DX is a dual frequency, dual beam unit, and generates two distinct   sonar signals - one narrow, one wide. Each signal is optimized for a   particular purpose. First, the center beam transmits at a frequency of 200   kHz in a 20 degree (narrow) symmetrical pattern for greater depth   capability and excellent detail. Information from this center beam is used to   draw the graphic representation of the bottom on the display.   Second, the wide beam transmits at a frequency of 83 kHz in a 53 degree   (wide) symmetrical pattern for greater area of coverage. Information from   the wide beam is used to accurately detect the presence and location of   fish. A wide beam has a large area of coverage but limited resolution of   detail. A narrow beam has excellent detail, but within a limited area   of coverage.   The combination of the two beams and dual frequencies provides the   combination of a large area of coverage and a high level of detail.   6 Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   SIMULATOR OPERATION   Actual depth capability depends on factors such as bottom hardness, water   conditions, and transducer installation. Units will typically read to deeper   depths in fresh water than in salt water.   SIMULATOR OPERATION   The 250DX contains a simulator that allows   you to use the unit as if you are on the water.   The simulator is invaluable for learning how   to operate the 250DX.   There are two ways to start the simulator. If   the unit is powered off, press and hold the   POWER button for approximately three   seconds until you hear a continuous chirp.   The simulator can also be started by selecting the Simulator option on the   start-up screen after you power-up the unit. When this screen is shown,   simply press the DOWN ARROW until “Simulator” is highlighted. When the   screen times out, the unit will be in simulator mode.   When in simulator operation, the 250DX responds to control inputs as if it   is in actual operation, so feel free to experiment, or to customize the unit   for your particular operation.   To exit Simulator mode, power the unit off.   When in simulator mode, the word “simulator” occasionally   scrolls across the display indicating the information on-screen is   not real sonar data.   FEATURE MEMORY   If your 250DX is installed with a transducer connected, any changes you   make to the set-up or User Options (see Control Functions) while in   Simulator are retained in the unit’s memory. This allows you to use   simulator to experiment with the various set-up options, and retain your   selected settings for normal operation.   7 Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   WHAT YOU SEE ON-SCREEN   If you are using the 250DX in Simulator when no transducer is connected,   any selected options are lost when the unit is powered off. The 250DX will   return to Factory Settings, or options selected when last used with a   transducer, if no transducer is connected.   IMPORTANT: A transducer must be connected to the 250DX in   order to retain user settings selected when in simulator mode. If   no transducer is detected, the unit defaults to pre-selected   options when powered off.   Figure A   What You See On-Screen   Your 250DX uses a 128 V x 64 H matrix   FSTN LCD display. This display provides   outstanding viewability in all light   conditions over a wide range of   temperatures.   At initial power-up, the 250DX uses   settings that were set at the factory.   After initial use, the 250DX will   remember the settings you enter.   There are several elements on-screen   that are common to all modes of   operation.   Temperature/Speed. The initial screen layout takes one of two basic forms   depending on whether the optional Temp/Speed accessory is installed. Figure   A shows the default view when the Temp/Speed accessory is installed. Figure B   shows the default view when the Temp/Speed accessory is not installed.   Depth. The digital depth number shows the water depth directly beneath the   transducer location.   Depth Range. The depth range is shown to the right of the screen. The upper   number is 0 indicating the surface of the water. The lower number is one of   the nine depth ranges available that best match the depth of the water. As the   8 Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   WHAT YOU SEE ON-SCREEN   Bottom Depiction   Zero Line   depth of the water changes, the range   changes as necessary in order to retain   a bottom representation on-screen.   When in Auto mode, the horizontal   line at the top of the screen is the   “zero line,” representing the surface   of the water. Occasionally there is a   gap in this line. This gap indicates the   unit is updating the display even if   the bottom is not visible on-screen,   or if the bottom information is not   changing.   New sonar information appears on   the right side of the graphic area of   the display and moves to the left as   new information is displayed. The   Water Depth   Depth Range   Figure B   250DX automatically selects the appropriate depth range to show the   depth of water beneath the transducer. This range is selected so the   bottom representation is typically shown about ²⁄₃ down the display.   Bottom. The graphic depiction of the   Surface Clutter   Rocky Bottom   bottom provides an effective tool for   understanding the composition of   the bottom. If the bottom is hard and   smooth, the bottom depiction is   narrow and dense. If the bottom is   soft mud or sand, the depiction will   be thick and less dense. This indicates   much of the signal is absorbed by the   soft bottom. If the bottom is rocky or   rugged in composition, the depiction   is of varying density and textured in   appearance.   Wave action also affects the bottom   depiction. The information drawn is a   Soft Bottom   Hard Bottom   9 Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   WHAT YOU SEE ON SCREEN   distance measurement, so if the boat is moving up and down over flat   bottom, the bottom depiction often appears in regular variations that match   wave timing.   Structure. Structure is defined as any object physically attached to the   bottom. The sonar configuration of the 250DX is optimized to give the most   accurate depiction of bottom structure possible. Grass, trees, stumps,   wrecks or other debris are accurately displayed, however the depiction of   these objects varies with boat speed and direction. The best way to learn to   interpret structure is to operate the 250DX over a variety of known   conditions and experiment with user functions to best represent those   conditions on-screen.   Surface Clutter. Surface clutter is the layer of water near the surface that   is rich in algae and other growth, and often is aerated by wind or wave   action. This area of water interferes with sonar transmission and often   appears on-screen as regular clusters of individual dots near the “0” line.   Thermoclines. Thermoclines are sharp   Thermocline Second Return   differences in water temperature.   These are easily identified by the   continuous nature of the return.   Second Returns. When a sonar signal   is reflected off the bottom back to the   transducer, there is often enough   energy left in the signal to be reflected   off the surface of the water back to the   bottom a second time. Second returns   appear as a slightly weaker bottom   representation exactly twice the depth   of the primary bottom return. The   second return is most likely to occur in   shallow water and in areas of relatively   hard bottom.   Fish ID. The 250DX uses advanced signal processing to further evaluate any   sonar return between the surface and the bottom. For instance, a small   school of bait fish usually appears as a dense cluster of individual dots. If the   10   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   CONTROL FUNCTIONS   Fish in Wide Beam   return meets certain additional criteria, a   fish symbol will be assigned. There are   three different size fish symbols used to   indicate the intensity of the sonar return.   While signal intensity is a good indicator   of relative fish size, different species of   fish have different sonar characteristics,   so it is not always possible to distinguish   fish size between varying species. The   signal intensity is "normalized" for   depth so that a small fish close to the   boat does not appear as a large fish   symbol.   ID+ adds an additional piece of   information to help the user locate fish.   On selected fish symbols, the digital   ID+ Fish Depth   Fish in Narrow Beam   depth of the designated fish is drawn to help locate the fish vertically. This   is especially helpful in setting bait depths or for downrigger operation.   The fish symbols indicate the sonar beam the fish is detected in. This   gives you a reliable indicator of side to side location of the fish relative to   the boat. Fish symbols that are hollow are detected in the wide beam and   are around the boat. Solid fish symbols represent fish detected in the   narrow beam and are directly under the boat.   CONTROL FUNCTIONS   The 250DX uses a simple five button keypad for all user   input. Press any button and an audible “chirp” confirms   the control input. If a button has no function or is   inappropriate for the situation, an audible “error” is   heard. The unit sounds multiple chirps.   Power. The Power button powers the 250DX up for   normal operation. When the unit is on, POWER turns   the unit off. POWER can also be used to go directly into   Simulator mode. To enter simulator, with the unit   11   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   CONTROL FUNCTIONS   powered off, press and hold POWER for several seconds until a continuous   chirp is heard.   Light. LIGHT controls the unit’s display backlight. With the unit powered   on, press LIGHT once to turn the backlight on “high.” Press LIGHT a second   time to turn the backlight on “low,” and a third time turns the backlight   off. The backlight is very effective for low-light and nighttime operation.   When the backlight is on, the 250DX will consume more power than with   the backlight off. This is important when using the 250DX in a portable   configuration powered by a separate battery, or when powering the unit   from a trolling motor battery.   When powering the unit from a battery such as in portable applications,   you can prolong the battery life by using the backlight at a minimum.   The three lower buttons, MENU, UP ARROW, and DOWN ARROW work   together to control the 250DX menu-controlled user functions.   Menu. MENU displays a menu on-screen   for adjustment. In normal operation,   Menu Heading   pressing MENU repeatedly cycles through   all available menu headings. When a   menu heading displays, the full menu   appears after a short pause. A menu remains on-screen for several seconds,   and can be adjusted by using the ARROW keys. If no adjustment is made   in the allotted time, the menu disappears. If you want the menu to remain   on-screen longer press and hold MENU—the menu will remain on-screen   indefinitely. Once you release the menu button, the screen will time out.   Once a menu times out, it is still considered the active menu. Press MENU   to bring up the last menu used.   Arrow Keys. The UP ARROW and DOWN ARROW make adjustments to   menu functions. On the left side of every menu there are UP ARROW and   DOWN ARROW symbols. The symbols indicate which ARROW button has   a function in a particular situation. Either one or both ARROW buttons can   be used to adjust the menu function. A hollow ARROW symbol means the   corresponding ARROW button has no function. Pressing that button will   result in no adjustment and the “error” audible will be heard. A solid   ARROW symbol means the corresponding ARROW button can be used to   12   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   CONTROL FUNCTIONS   affect the menu adjustment.   The ARROW buttons often can be used   when no menu is on-screen. In these   situations, pressing the ARROW button   affects the function of the active (last-   used) menu. This is a short-cut to menu   operation. The menu appears on-screen while the adjustment is made and   times out. A frequently used menu can be adjusted very quickly using this   technique.   After an adjustment is made to a menu function, the menu times out after   a few seconds and the unit returns to normal operation.   Menu Layout. All menus use the same basic layout. The heading at the   top describes the menu function. The UP ARROW and DOWN ARROW   symbols to the left of the menu indicate which buttons are available for   adjustment. In menus that have several possible settings, a range of   adjustment indicator shows the total range available and the current   setting.   Within the menu are the options available. The selected option or current   setting is highlighted in the black box. If no adjustment is made, this is the   selected setting. Press an ARROW button while the menu is displayed to   select another option.   Several of the menus are multi-step. In some situations if an adjustment is   made, additional options become available for further adjustment.   Examples of these multi-step menus are Depth Range, Depth Alarm and   Zoom. See the detailed description of each function for further   explanation.   Heading   Up Arrow Option   Arrow Symbols   Selected Setting   Down Arrow Option   Range of Adjustment Indicator   13   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Menu Functions   Sensitivity. The Sensitivity function controls the   sensitivity of the sonar receiver. The 250DX   automatically adjusts the level of receiver sensi-   tivity based on a number of factors including   the depth of the water and the level of noise   present. Noise can be caused by other electronic devices, engines, trolling   motors, propeller cavitation and hydrodynamic flow among others.   The user has the option of adjusting the Sensitivity higher or lower based on   personal preference. You can select one of 11 sensitivity settings from -5 to +5.   A setting of 0 (factory setting) has no effect on the automatic sensitivity control.   Increasing the sensitivity (+1 through +5) enables the unit to display the informa-   tion from progressively smaller sonar returns. By decreasing the sensitivity bias (-   1 through -5), the unit effectively filters small sonar returns.   In murky or muddy water, it is often helpful to reduce the sensitivity. This   prevents the display from being cluttered with sonar returns from debris or sus-   pended particles. In very clear or very deep water, it may be helpful to increase   the sensitivity since even the smallest sonar return may be of interest to the user.   To adjust Sensitivity, press MENU   High(+) Sensitivity Low(-) Sensitivity   repeatedly until the Sensitivity heading is   displayed. When the Sensitivity menu   appears, use the UP ARROW to increase   the sensitivity, or the DOWN ARROW to   reduce sensitivity. To sequence through   the available settings, press and hold   either ARROW button. Release the button   at the setting you want to change.   After an adjustment is made, the menu   disappears and the new sensitivity setting   is in affect. If additional time is needed to   study a menu, press and hold the MENU   button and the menu will remain on-   screen indefinitely. If you need to make an   additional adjustment, press the UP   ARROW or DOWN ARROW button.   Sensitivity at “0”   14   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Depth Range. The Depth Range function   controls the vertical distance displayed on   the graphic area of the display. There are   nine depth ranges available. The top of the   range is always 0, or the surface of the   water. Ranges of 0–15', 0–30', 0–60',   0–120', 0–180', 0–240', 0–360', 0–480',   and 0–600' are available. In the metric version, ranges of 0–5, 0–10, 0–20,   0–40, 0–60, 0–80, 0–110, 0–150, and 0–185 metres are available.The   range that positions the bottom depiction closest to the bottom of the   screen, will best utilize the available display resolution.   The 250DX automatically adjusts the depth range depending on the depth   of the water. The unit tries to maintain the bottom depiction about ²⁄₃   down the total range (for example, in 20' (6m) of water, the 0-30' (0-10m)   range would be selected). This provides the best display resolution and   therefore the best target separation possible.   The Depth Range can be adjusted   manually. Press MENU repeatedly until the   Depth Range menu is visible. Two options   are available: Auto and Manual.   The manual setting enables you to adjust   the current depth range setting. The unit   no longer adjusts the Depth Range to the   most appropriate range for bottom   display. Often, the bottom may not be visible on-screen. The digital depth   readout always determines the depth of the bottom, even if it is not visible   on-screen.   Using manual Depth Range control, you   can view sonar information from the area   near the surface in great detail.   15   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   To return to automatic Depth Range   control, press the MENU button until   the Depth Range menu appears on-   screen and use the UP ARROW to   select AUTO.   Zoom. Zoom is similar to Depth Range   because it controls the range of information   displayed on screen. Zoom, however,   allows selection of ranges beneath the   surface so any area of water between the   surface and the bottom can be enlarged to   provide more detailed information. By using   the full display to show a small area of   coverage, the effective display resolution is   increased, and the unit’s ability to separate   close targets is enhanced.   Depth Range   There are four Zoom ranges available: 2m (7¹⁄₂'),   5m (15'), 10m (30'), and 20m (60'). These   ranges are not directly user controlled but are   instead dependent on the current depth range.   In shallow water, when the 5m (15') or 10m   (30') range is in use, the Zoom range is 2m   (7¹⁄₂'). If the 20m (60') or 40m (120' ) range is in   use, the Zoom range is 5m (15'), if a 60-   150m (180'-480') depth range is in use, the   Zoom range is 10m (30'), and if the 185m   (600') range is in use, the Zoom range is   20m (60').   Upper Zoom Limit   The Zoom range is shown on the left side   of the screen and full range information is   shown on the right side of the display.   Zoom can either operate automatically, in   which the Zoom range is constantly   adjusted to show the bottom, or manually,   in which the user controls the location of   the Zoom range.   16   Lower Zoom Limit   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Automatic Zoom is especially helpful when looking for structure or bottom   detail. The Automatic Zoom keeps the bottom in view even in quickly changing   terrain, but is most useful in flatter areas without considerable depth variation.   Manual Zoom provides detailed information of any area from the surface to the   bottom. In manual Zoom, the Zoom range does not move as the terrain   changes.   When the range is shown in the menu, the upper   number represents the top of the current Zoom   range. The lower number represents the bottom of   the Zoom range. Use the UP and DOWN ARROW   buttons to move this range. The upper number can   never be less than 0 (the surface of the water), and   the lower number can never be greater than the   active depth range. The difference between the   two numbers (the Zoom range) is preset and   determined by the active depth range.   Once manual Zoom is selected, the display   appears the same as in Auto Zoom, but the zoom   range does not change automatically.   To disable Zoom, press the MENU button until the   Zoom menu is on-screen. Use the UP ARROW to   highlight Off, and let the menu time out.   When the unit is powered off, the Zoom menu   returns to Zoom Off.   Depth Alarm. The 250DX contains an audible   alarm to warn you of shallow water depths. The   alarm is adjustable to depths of 1m (3') to 30m   (99'). When the alarm is enabled, an audible   alarm sounds if the water beneath the boat is   equal to or less than the selected alarm depth.   The alarm sounds continuously for about five   seconds, and then intermittently to remind you   that you are still in shallow water.   17   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Fish Alarm. The Fish Alarm alerts you to the   presence of fish, or other targets not connected to   the bottom. The Fish Alarm has three different   settings that correspond to the three different size   fish symbols shown on-screen.   The default setting is “OFF.” With the “Large fish   only” setting, the 250DX alarms on only those   targets that are represented by the large fish   symbols. The 250DX can be set to alarm on only   large and medium fish, or set to alarm on all fish.   Once the Fish Alarm is enabled, the 250DX emits an   audible beep when the selected size fish symbol   appears on-screen.   Set for large fish only   Set for large and medium fish   Set for all fish   Triplog. Triplog provides a running log of   information based on input from the Temp/Speed   sensor.   Since Triplog requires information from the   Temp/Speed sensor to operate, if this sensor   is not detected by the 250DX, the Triplog menu will not appear as   an option.   Triplog provides seven pieces of information: the current digital depth, water   surface temperature, current boat speed, the distance traveled since the 250DX   was powered up or reset, the average speed, the total time elapsed since   power-up or reset, and the input voltage from your boat’s electrical system.   The time, speed and distance calculations are useful for tracking your progress   on a trip. The input voltage is useful for determining the condition of the   charging system of the boat. When used in a portable application or whenever   18   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   the 250DX is operated from a battery   source, the voltage number can be used to   determine battery life. The 250DX will   operate at voltages from 10 to 20 VDC.   Voltages in excess of 20 or less than 10   VDC cause the unit to power off.   Options. The Options Menu is a series of   linked menu functions used initially to set   your preferences. Once your preferences   are selected, it is unlikely these functions   need to be accessed during the normal   operation of the product.   The Options menu works differently   than other menu functions in that all of the   options must be cycled through in order to   return to normal operation. There are thirteen   Option menus: Contrast, Display Speed,   Battery Alarm, Bottom Black, Fish ID, Numeral   Size, Diagnostic, Units, Languages, Speed   Offset, Depth Offset, Filter and Reset.   Contrast. The Contrast function allows the   user to control the level of contrast of the   LCD display. The 250DX will automatically   adjust the display contrast to compensate for   changing ambient temperatures; however,   some situations may occur where manual   adjustment will provide a higher level of contrast.   Eleven contrast settings, +5 to -5, are   possible. The display contrast will change as   the adjustment is made so the optimum level   of contrast can be achieved. Use the ARROW   buttons to highlight the desired selection.   The 250DX will reset to the factory setting   when the unit is powered off.   19   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Display Speed. Display Speed controls   the rate at which the graphic information   moves across the display. There are 5   possible speeds; the fastest rate (5) is the   factory setting. Keep in mind that the   closer the update rate matches your boat   speed, the more accurate is the graphic   depiction of the terrain beneath your boat.   Use the UP and DOWN ARROWS to select the desired update rate. The   Display Speed setting is remembered when the unit is powered off.   Battery Alarm. The Battery Alarm   Option allows you to select the voltage   level at which the Battery Alarm   activates.   At the Battery Alarm menu (under   options), you will note that the default   setting is OFF. Push the DOWN ARROW   BUTTON to select the feature ON. Push the DOWN ARROW BUTTON again   to move into the ADJUST BATTERY ALARM setting. Using the UP and   DOWN ARROW BUTTONS, select a voltage between 9.0 and 12.0.   When the voltage drops below your selected voltage, an audible alarm will   sound, and a battery alarm icon will be displayed on screen with current   voltage level.   Bottom Black. There are two selections   available: OFF and ON. The factory setting   is OFF. With this setting, the 250DX   displays the bottom using Structure ID.   This allows you to determine the texture   and relative hardness of the bottom.   Selecting Bottom Black “ON” causes the   unit to blacken in the display below the bottom. This gives the user easiest   recognition of the bottom location, even from a great distance.   The 250DX remembers the Bottom Black setting when powered off.   20   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Fish ID. There are three selections available:   Bottom Black View   OFF, ID+ ON, and ADJUST. The factory   setting is ID+ ON. With Fish ID OFF, sonar   returns are displayed as “raw” information.   There is no interpretation made by the unit.   Selecting ID OFF also disables the fish alarm.   ID+ ON enables the 250DX to interpret   the raw sonar data and, using a variety   of techniques, depict appropriate target   returns as one of three different size fish   symbols. Further identification shows   whether the fish is in the wide or narrow   beam. The 250DX also displays the   depth beneath the surface with the   corresponding fish symbol.   Selecting Adjust and making incremental changes   enhances the fishfinder’s ability to identify sonar   returns as fish symbols.   Increasing the value to a number greater than zero   shows more fish symbols on-screen. In this case   smaller sonar returns will be depicted as fish   symbols. This is useful for identifying many smaller   sonar returns (such as baitfish) as fish symbols.   Decreasing the value to a number less than zero shows   fewer fish symbols on-screen. In this case smaller sonar   returns are disregarded. This is useful for eliminating   many small sonar returns   Raw Sonar   ID+ On   when seeking larger species   of fish.   The 250DX remembers this selection even when   the unit is powered off.   21   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Numeral Size. Two options are available:   BIG and SMALL. The factory setting is BIG.   With this setting, the digital depth and   speed and temp numerals are drawn large   enough to be read from across the boat.   The big numerals occupy space on the   display that could be used for the graphics   area. Hence, the small numerals option. With small numerals selected, a   greater amount of the display area is available for the graphic view. This   effectively increases the display resolution of the unit.   Numeral Size settings are remembered when   powered off.   Diagnostic. Two options are available: HIDE and   SHOW. The factory setting is HIDE. Selecting SHOW   brings up the Diagnostic screen. See the Using   Diagnostic section for more information.   Units. The Units function allows the user to   select the units of measurement for the depth   and speed readout. Metres/KTS, (metres/nautical   miles per hour), Metres/KPH (metres/kilometres   per hour), FEET/MPH (feet/statute miles per hour)   and FEET/KTS (feet/nautical miles per hour), are   available.The 250TX remembers this selection   even when the unit is powered off.   Languages. The language menu displays   one of two sets of languages. Language set   A includes: English, French, Italian, German,   Norwegian, Swedish, Spanish, and Finnish.   Language Set B provides Hungarian, Danish,   Polish, Portuguese, Dutch and English. To   select your language, push the UP or Down   Arrow Buttons to scroll through the list.   22   Download from Www.Somanuals.com. All Manuals Search And Download.   USING THE 250DX   MENU FUNCTIONS   Speed Offset. The Speed Offset option allows the   user to compensate for differences in hull design, and   its effect on the accuracy of the speed measurement.   If there is a discrepancy between the indicated speed   and another speed measurement device on the boat,   the speed measurement can be varied to improve   accuracy. Remember, the speed paddle wheel   measures speed through the water, not speed over ground.   Speed offset is remembered after power is disconnected.   Depth Offset. The Depth Offset allows the user to   select the point on the boat from which the depth   measurement is made. Selecting a positive value adds   distance to the measurement. If the transducer is   mounted 3 feet beneath the waterline, a positive 3   will show the correct depth from the surface of the   water.   Another frequent use of depth offset is to show the depth beneath the   deepest point of the hull. A negative value equal to the distance from the   transducer location and the deepest point of the hull will have the same   effect as mounting the transducer at the deepest point.   Depth offset is remembered after power is disconnected.   Filter. Filter provides an advanced level of control   over the amount of detail visible on-screen and the   sensitivity of the unit. You can choose the setting(s)   that works best for your style of use.   With Filter set to OFF, the 250DX displays increased   detail, showing more thermoclines, structure, fish and even your bait when it falls   within the sonar cone. However, this extreme sensitivity requires you to optimize the   installation of your unit and transducer so that “noise” generated by a moving boat   is not picked up by the fishfinder.   With Filter set to ON, excessive clutter often caused by interference from other   fishfinders, your boat‘s engine, or from noise generated by the hull at high speeds   is reduced in the display. This provides a cleaner image on the display in most cases.   With the Filter menu on screen, use the arrow keys to select the setting for your   boat. When finished, press MENU to display the sonar screen.   23   Download from Www.Somanuals.com. All Manuals Search And Download.   ADVANCED FEATURES   USING DIAGNOSTIC   Reset. With the many User Options available to   customize the 250DX, it is easy to configure the unit   in such a way that it is detrimental to a particular   use. By using the Reset function, all variable or user-   controlled features (except Filter) of the 250DX are   returned to the factory settings.   The Reset function is an important first step in troubleshooting problems to   ensure that a user selected setting is not the cause for the perceived   problem.   USING THE DIAGNOSTIC FEATURE   The 250DX contains a powerful diagnostic tool that can aid in determining   the cause of a problem.   To use the Diagnostic feature, select the Diagnostic feature on the start-up   menu on the initial screen. Diagnostic can also be accessed through the   Options menu.   Self Test. Initially, the 250DX will perform a self-test.   This test confirms the operation of all internal circuitry.   At the conclusion of the test, one of two messages will   appear. PASSED indicates the internal test discovered   no failures, FAILED indicates a significant internal   problem was discovered and the unit requires factory   service. A code number appears that tells repair   personnel where the problem is.   Transducer Connection. The first connection tested is   Transducer input. If a transducer is detected, the   message CONNECTED appears. If a series of dashed   lines is shown, no transducer is connected or there is   a problem with the transducer or cable.   If you are using multiple transducers, switch between   transducers to confirm the connections for each.   24   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   MAINTENANCE   Boat Speed/Water Temperature Connection. Other connections tested   include the boat speed and surface water temperature sensors. These   accessory sensors can be purchased independently or together as a single   sensor (see the Humminbird Accessories catalog). If the sensors are   connected and working properly, a “connected” message appears.   The speed input feature only works when the boat is in motion as the   paddle wheel on the speed sensor must rotate to be detected.   Voltage Input. Another connection tested is the voltage input, and is   especially helpful in diagnosing input voltage problems. The current input   voltage is displayed. If voltage fluctuations or power supply in excess of 20   VDC or less than 10 VDC is suspected, use the diagnostic screen to confirm   input voltage. Often, small outboard motors do not effectively regulate   voltage when operated at high engine speeds.   Use Diagnostic while running the boat at high speeds to show the voltage   gain. Also, if you are using the 250DX in portable configuration or from the   trolling motor battery, Diagnostic can be used to evaluate the health of the   battery by showing the current voltage.   Total Time. The total time category indicates the total time the unit has   been in use since shipped from the factory. It is normal for some hours to   appear in the total time when the unit is new due to factory testing. While   this is often of interest to the user, it is primarily a diagnostic tool for the   repair technician should the unit need service.   MAINTENANCE   Your 250DX is designed to provide years of trouble free operation with   virtually no maintenance. Follow these simple procedures to ensure your   250DX continues to deliver top performance.   • If the unit comes into contact with salt spray, simply wipe the affected   surfaces with a cloth dampened in fresh water. Do not use a chemical   glass cleaner on the lens. Chemicals in the solution may cause cracking in   the lens of the unit.   • When cleaning the LCD protective lens, use a chamois and non-abrasive,   25   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   TROUBLESHOOTING   mild cleaner. Do not wipe while dirt or grease is on the lens. Be careful to   avoid scratching the lens.   • If your boat remains in the water for long periods of time, algae and   other marine growth can reduce the effectiveness of the transducer.   Periodically clean the face of the transducer with liquid detergent.   Pivoting the transducer up in the bracket may allow better access for   inspection or cleaning.   • If your boat remains out of the water for a long period of time, it may   take some time to wet the transducer when returned to the water. Small   air bubbles can cling to the surface of the transducer and interfere with   proper operation. These bubbles dissipate with time, or you can wipe   the face of the transducer with your fingers after the transducer is in   the water.   • Never leave the 250DX in a closed car or trunk—the extremely high   temperatures generated in hot weather can damage the electronics.   TROUBLESHOOTING   Do not attempt to repair the 250DX yourself. There are no user serviceable parts   inside, and special tools and techniques are required for reassembly to ensure   the waterproof integrity of the housing. Repairs should be performed only by   authorized Humminbird technicians.   Many requests for repair received by Humminbird involve units that do not   actually need repair. These units are returned “no problem found.” If you have   a problem with your 250DX, use the following troubleshooting guide before   calling Customer Support or sending your unit in for repair. The 250DX contains   several tools that can aid in determining if there is a problem and how to isolate   and repair the problem in many cases.   1. Nothing happens when I turn the unit on.   Check the power cable connection at both ends. Be sure the cable is connected   correctly to a reliable power source—red lead to positive, black lead to negative   or ground. Ensure the power available at the mount is between 10 and 20 VDC.   26   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   TROUBLESHOOTING   If the unit is wired through a fuse panel, ensure the panel is powered. Often   accessory fuse panels are controlled by a separate switch or the ignition switch.   Also, often a fuse can appear to be good when in fact is not. Check the fuse   with a tester or replace it with a fuse known to be good.   Check the power connection to the 250DX. It is possible to force the power   cable connector into the cable holder incorrectly. If the connector is reversed, the   unit will not work. Examine the contacts on the back of the unit to ensure there   is no corrosion. Finally, ensure the unit is firmly seated on the mount. The   electrical contacts are not made until the unit is fully seated.   Ensure the metal cable retainer is properly installed in the mount. If not, the   power connected may push out when the unit is put on the mount.   2. There is no transducer detected.   The 250DX has the ability to detect and identify that a transducer is connected.   If, at power up, a message indicates “transducer not connected,” only simulator   operation is possible. First, ensure that an appropriate transducer connector is   positioned correctly in the connector holder, and that the unit is fully seated on   the mount. The 250DX will work with the standard tri-beam transducer.   Second, inspect the transducer cable from end to end for breaks, kinks, or cuts   in the outer casing of the cable. Also ensure the transducer is fully submerged   in water. If the transducer is connected to the unit through a switch, temporarily   connect it directly to the unit and try again. If none of these items identifies an   obvious problem, the transducer itself is probably the problem. Be sure to in-   clude the transducer if returning the unit for repair.   3. There is no bottom reading visible on the display.   There are a number of possible causes for this condition. If the loss of bottom   information occurs only at high boat speeds, the transducer needs adjusting. If   the digital depth readout is working but there is no bottom visible on-screen, it   is possible the depth range has been adjusted manually to a range lower than   what is needed to display the bottom. Also, in very deep water, it may be   necessary to manually increase the sensitivity setting to maintain a graphic   depiction of the bottom.   27   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   TROUBLESHOOTING   If you are using a transducer switch to connect two transducers to the 250DX,   ensure the switch is in the correct position to connect a transducer that is in   water. (If a trolling motor transducer is selected and the trolling motor is out of   water, no sonar information appears.)   If none of the above solve the problem, inspect the transducer cable from end   to end for breaks, kinks, or cuts in the outer casing of the cable. If the transducer   is connected to the unit through a switch, temporarily connect it directly to the   unit and try again. If none of these items identifies an obvious problem, the   transducer itself may be the problem. Be sure to include the transducer if   returning the unit for repair.   4. When in very shallow water, I get gaps in the bottom reading and   inconsistent digital depth indication.   The 250DX will work reliably in water 1m (3') or deeper. The depth is measured   from the transducer, not necessarily from the surface.   5. The unit comes on before I press POWER, and won’t turn off.   Check the transducer cable—if the outer jacket of the cable has been cut and   the cable is in contact with bare metal, you need to repair the cut with electrical   tape. If there is no problem with the cable, disconnect the transducer from the   unit and see if the problem is corrected, to confirm the source of the problem.   6. I get gaps in the reading at high speeds.   Your transducer needs adjusting. If the transducer is transom-mounted, there   are two adjustments available to you—height, and running angle. Make small   adjustments and run the boat at high speeds to determine the effect. It may take   several tries to optimize high speed operation. This can also be a result of air or   turbulence in the transducer location caused by rivets, ribs, etc.   28   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   TROUBLESHOOTING   7. My unit loses power at high speeds.   Your 250DX has over-voltage protection that turns the unit off when input   voltage exceeds 20 VDC. Some outboard motors do not effectively regulate the   power output of the engine’s alternator and can produce voltage in excess of 20   volts when running at high RPMs. The 250DX displays input voltage in the   Diagnostic screen. Use this readout to determine if the voltage exceeds 20 VDC.   8. The screen begins to fade out. Images are not as sharp as normal.   Check the input voltage using Diagnostic. The 250DX will not operate on input   voltages below 10 VDC.   9. The display shows many black dots at high speeds and high   sensitivity settings.   You are seeing noise or interference caused by one of several sources.   Noise can be caused by other electronic devices. Turn off any nearby   electronics and see if the problem goes away. Noise can also be caused by   the engine. If engine noise is causing the interference, the problem will   intensify at higher RPMs. Increase the engine speed with the boat   stationary to isolate this cause. Propeller cavitation can appear as noise on-   screen. If the transducer is mounted too close to the propeller, the   turbulence generated can interfere with the sonar signal. Ensure that the   transducer is mounted at least 15" (38cm) from the prop.   29   Download from Www.Somanuals.com. All Manuals Search And Download.   MAINTENANCE   CUSTOMER SUPPORT   CUSTOMER SUPPORT   If you have any problems or questions with your Humminbird unit, contact   your local distributor.   Humminbird   Service Department   108 Maple Lane   Eufaula, AL 36027   USA   30   Download from Www.Somanuals.com. All Manuals Search And Download.   SPECIFICATIONS   Operating Frequency . . . . . . . . . . . . . . . . . . . . .200 kHz and 83 kHz   Power Output . . . . . . . . . . . . . . . . . . . . . . . . . . . .250 Watts (RMS)   2000 Watts (Peak to Peak)   Area of Coverage . . . . . . . . . . . . . . . . . . . . .Narrow: 20° at -10 db   Wide: 53° at -10 db   Power Requirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 VDC   Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FSTN LCD   LCD Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . .128 V x 64 H Pixels   Viewing Area . . . . . . . . . . . . . . . . . . . . . . . . . . .2.90" V x 2.35" H   (7.3cm V x 5.97cm H)   Mounting . . . . . . . . . . . . . . . . . . . . . . . . .Quick Disconnect Mount   Unit Size . . . . . . . . . . . . . . . . . . . . . . . . . .6³⁄₄"H x 6¹⁄₄"W x 4¹⁄₄"D   (17.1cm H x 15.9 cm W x 10.5 cm D)   Transducer (Standard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XT-6-20   Transducer Cable Length . . . . . . . . . . . . . . . . . . . . . . .20' (6 metres)   Depth Ranges . . . .15', 30', 60', 120', 180', 240', 360', 480', & 600'   (5, 10, 20, 40, 60, 80, 110, 150 & 185 metres)   Zoom Ranges . . . . . . . . . . . . . . . . . . . . . . . . . .7¹⁄₂', 15', 30', & 60'   (2, 5, 10 & 20 metres)   31   Download from Www.Somanuals.com. All Manuals Search And Download.   Use with XT series Transducers   Download from Www.Somanuals.com. All Manuals Search And Download.   P/N 530975-2   Download from Www.Somanuals.com. All Manuals Search And Download.   Download from Www.Somanuals.com. All Manuals Search And Download.   |