Garmin FishFinder 340C Owner's Manual

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Garmin FishFinder 340C Owner's Manual Manual pdf 8 page image

2 Fishfinder 340C Owner’s ManualGETTING STARTED > U NDERSTANDING THE FISHFINDER AND SONARUnderstanding the Fishfinder and SonarThe Fishfinder 340C is a fully automatic, color sonar unit thatallows you to go out on the water and find fish without having toconfigure a lot of settings; or, if from experience you know exactlyhow you want your Fishfinder screen to look and function, you cancustomize each setting to your specific needs and wants.If you have used a Fishfinder before, you might already know howto interpret the sonar information on the screen, so you can skipthis section. If you have not used a Fishfinder before, you mightwant to learn a bit about sonar: what it is, how it works, and whatyou might see on the Fishfinder 340C screen. This manual does notgo into technical detail about sonar, but it can give you a generalunderstanding of those things that you need to know about sonarthat can help you interpret the screen and find the fish.Understanding SonarDuring installation, you connect your Fishfinder 340C to atransducer. The transducer uses sound to determine informationabout what is in the water beneath your boat. Then the transducersends the information to your Fishfinder to be displayed on thescreen for you to view and interpret. How does the transducer dothis?The transducer sends sound waves down into the water in a coneshape, similar to a flashlight beam (covering a smaller circular areaat the top and angling out to a larger circular area at the bottom).These sound waves reflect off of any object that they hit, and thenthe waves travel back up to the transducer. These objects could befish, branches, the bottom, or any other object that has density thatis different from the water. The transducer receives the sound waveinformation, and then sends the information to the Fishfinder. TheFishfinder displays the information on the screen for you to seeand interpret. The type of transducer and settings that you choosedetermine how the information is displayed on the screen.Using Dual FrequencyDual frequency works best for deep water (for example, off-shore)applications. The 200 kHz frequency allows you access to greatdetail about what is underneath your boat. The 50 kHz frequencyprovides less detailed information, but penetrates to greater depthswith the same power. You can choose either or both frequencies toget the information that you want. If you choose dual frequency,the transducer alternates between the 50 kHz and 200 kHz signals.This capability allows you to see the best picture available at anydepth.