Insignia manual Using the 250DX, HOW Sonar Works

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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.

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Contents Operations Manual Thank YOU Table of Contents Installation Preparation AccessoriesInstallation Overview Parts SuppliedInstallation Overview Determining How to Mount the TransducerAlternate Transducers and Mounting Methods Alternate Transducers and Mounting MethodsPortable Mounting Trolling Motor MountingTransducer Exchange Beginning InstallationTransducer Exchange HOW Sonar Works Using the 250DXHOW Sonar Works Simulator Operation Feature MemorySimulator Operation What YOU see ON-SCREEN What You See On-ScreenDepth of the water changes, the range What YOU see on Screen Control Functions Control FunctionsUsing the 250DX Using the 250DX Menu Functions Menu FunctionsUsing the 250DX Depth Range Upper Zoom Limit To disable Zoom, press the Menu button until Fish symbols shown on-screen Using the 250DX Using the 250DX Using the 250DX Numeral Size. Two options are available Using the 250DX Using the Diagnostic Feature Advanced FeaturesUsing Diagnostic Maintenance MaintenanceMaintenance Nothing happens when I turn the unit on TroubleshootingTroubleshooting There is no transducer detected There is no bottom reading visible on the displayUnit comes on before I press POWER, and won’t turn off Get gaps in the reading at high speedsMy unit loses power at high speeds Screen begins to fade out. Images are not as sharp as normalCustomer Support Customer SupportSpecifications TOP