How Sonar Works - VEXILAR FL-8 SE Owner's Manual

How Sonar Works

SONAR stands for SOund NAvigation and Ranging. Sound travels through fresh water at a speed of approximately 4,920 feet per second.
A sonar device (depth finder/fish-finder) measures the amount of time a burst of energy takes to travel to the bottom and return to the
transducer. This time variation is then displayed on the readout of your sonar. When the depth gets deeper, the time of travel for the
sound increases. The burst of energy, known as the transmit pulse, is generated by the sonar's transmit circuitry. This burst is delivered
to the water via the transducer. The return signal, known as the echo, is received by the receiver circuit, also via the transducer. A central
processing unit makes the calculations to determine the depth and signal strength of the bottom and other targets.
The sonar signal sent from the transducer will reflect, or bounce off of any object that has a different density than water. This makes it
possible to detect not only the lake bottom, but also vegetation and fish.
Flasher Wheel Stationary
How Flashers Work
Lights turn on
and off rapidly
The sonar portion of a flasher works in the same manner as any other graph or LCD sonar
as the wheel is
spun
device. The difference is in how the return signal is displayed. Instead of adding the data to a
progressive representation of the bottom to construct a history, the data on the flasher display
always represents the current point in time, also known as "real time." The display consists of
a wheel with indicator lights mounted in one location. The wheel is spun at high speed and the
lights turn on and off rapidly to show the sonar readings.
The Vexilar Advantage
Vexilar's sonar design offers an optimal balance between the power of the transmitted pulse and the sensitivity
of the receiver circuit. Excessive power has been shown to cause premature transducer failure, distortion of the
sonar signal, and possibly spook fish from the audible noise they hear. Vexilar provides a balanced performance
level for a wide range of fishing scenarios.
3
Flasher Wheel Spinning