How your Sonar Works. Lowrance electronic LCX-104C

Position updates: .......... Every second.

Position points: ............. 1,000 waypoints; 1,000 event marker icons.

Man Overboard: ............. MOB feature precisely marks man overboard location with special icon, then automatically displays navigation data to that position.

Audible alarms: ............. Arrival/off-course/destination passed/anchor.

Graphic symbols for waypoints or event marker icons: ................. 42.

Routes: ............................. 100; up to 100 waypoints per route.

Plot Trails: ...................... 10 savable; up to 9,999 points per trail.

Zoom range: .................... 37 ranges; 0.05 to 4,000 miles.

NOTE:

The above memory capacities refer only to the unit's on-board memory. The amount of GPS or sonar data you can record and save for recall later is only limited by the number of MMC cards you have.

NOTICE!

The storage and operation temperature range for your unit is from -4 degrees to +167 degrees Fahrenheit (-20 degrees to +75 degrees Celsius). Extended storage or operation in temperatures higher or lower than specified will damage the liquid crystal display in your unit. This type of damage is not covered by the warranty.

For more information, contact the factory's Customer Service Department; phone numbers are listed on the last page.

How Your Sonar Works

Sonar has been around since the 1940s, so if you already know how it works, skip down to read about the relatively new technology of GPS.

But, if you've never owned a sonar fish finder, this segment will tell you the underwater basics.

Sonar is an abbreviation for SOund NAvigation and Ranging, a technology developed during World War II for tracking enemy submarines.

(Lowrance developed the world's first transistorized sportfishing sonar in

1957.) A sonar consists of a transmitter, transducer, receiver and display. In simple terms, here's how it finds the bottom, or the fish:

The transmitter emits an electrical impulse, which the transducer converts into a sound wave and sends into the water. (The sound frequency can't be heard by humans or fish.) The sound wave strikes an object

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