Lowrance electronic M56 GPS Receiver User Manual


 
4
GPS
Receiver/antenna:......... Internal 12 parallel channel GPS/WAAS.
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:.................... 39 ranges; 0.02 to 4,000 miles.
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 NA
vigation and Ranging, a technol-
ogy 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 dis-
play. In simple terms, here's how it finds the bottom, or the fish:
The transmitter emits an electrical impulse, which the transducer con-
verts 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
(fish, structure, bottom) and bounces back to the transducer, which
converts the sound back into an electrical signal.