Glossary - Humminbird 777C2 Operation Manual

531474-1_A_777c2_English.qxd 11/3/2005

Glossary

Sonar Terms:
Alarm, Depth: Depth Alarm is a user-controllable, audible alert that sounds when
depth is less than or equal to the setting.
Alarm, Temperature: Temperature Alarm is a user-controllable, audible alert that
sounds when the water surface temperature equals the setting.
Backlight: Backlight is a user-controllable illumination for the LCD for night and low
light use.
Beam (Sonar Beam): A sonar beam is the cone-shaped projection of sound waves
formed as sound travels underwater. See Cone Angle.
Big Digits View: Big Digits View is a Humminbird® feature that displays the sonar
graph and enlarged digital readouts for easy reading from a distance. This is a great
tool when monitoring the digital depth is important - such as with higher boat
speeds, or when viewing the unit from a distance. When speed input is available, the
Big Digits View also shows the TripLog. See TripLog.
Bottom Black: Bottom Black is a Humminbird® feature that "fills in" the area of the
display below the bottom contour. Bottom Black is preferred by some anglers
because of its high contrast and easy readability, even though it can obscure bottom
hardness information.
Bottom Contour: Bottom Contour is the profile of the bottom graphed to the display
as the depth changes.
Bottom Hardness: Bottom Hardness is the density (or composition) of the bottom,
which can often be determined by interpreting the main sonar return. Varying levels
of hardness can be determined by interpreting the "thickness" of the sonar return.
Hard returns appear thin and black, softer returns appear thicker and less black. It is
important to note that a sonar return from a sloping bottom can have the
appearance of a softer bottom.
Cavitation: Cavitation is the effect of air bubbles created as the propeller rotates and
the boat moves through the water.
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Chart Speed: Chart Speed is a user-controllable feature that sets the speed at which
sonar information moves across the display. A faster setting displays sonar information
from more pings and shows more detail, but the information moves quickly across the
display; a slower setting permits viewing of more sonar history, but does not display as
much detail. The best setting is often the user's personal choice.
Cone Angle: The cone angle is the angular measurement of the sonar beam at a
specific dB down point (i.e. -10 dB). See dB Down Point.
Customizable Digital Readouts: Customizable Digital Readouts is a Humminbird®
feature that permits the user to select the specific digital information that appears
in the main Sonar view (i.e. Speed, Temperature, Barometric Pressure, TripLog, etc.)
Dead Zone: The dead zone is the area of the sonar beam that is received after the main
bottom return. Fish and other objects close to the bottom that fall within the dead zone
will probably not be visible in the sonar beam. Precision sonar beams, such as the
Humminbird® 20° beam, have a smaller dead zone than wider sonar beams.
Decibel: A Decibel is the measurement for sound pressure level, or "intensity" of the
sonar return. See dB Down Point.
dB Down Point: The dB Down Point is the standard decibel level at which the sonar
cone angle is measured, and is written as "@ -10 dB" or "@ -3 dB". Measurements at
smaller down points (bigger negative numbers) indicate that the less intensive
sonar signals are being used for the measurement.
Display, FSTN: FSTN is an acronym for Film Super-Twist Nematic. FSTN is a
monochrome display technology characterized by black, high-contrast pixels. All
monochrome fixed mount Humminbird® products use FSTN technology.
DualBeam PLUS™: DualBeam PLUS™ is a Humminbird® sonar configuration that
uses two sonar beams simultaneously, and combines the information from both
beams into one view by overlapping the data on-screen, or shows each beam
individually side by side, or permits each beam to be viewed individually full screen.
Feature Memory: Feature Memory is a Humminbird® feature that retains the user's
menu settings in permanent memory. Settings are retained even when the unit is
powered off indefinitely.
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