Garmin GPSMAP 8530 Black Box - Manual (Page 17)

1 From a Sonar view, select Menu > Sonar Menu >
Frequency.
2 Select an option:
• To sweep each pulse through a range of frequencies to
deliver shallow-water-like target separation at extremely
deep depths and at low frequencies, select High Chirp or
Low Chirp. This is useful mainly for very deep, offshore
waters and when targeting some species of fish.
• To show data from a 200 kHz sonar signal, select 200
kHz. This is useful mainly for more-shallow, inland waters.
• To show data from an 80 kHz sonar signal, select 80 kHz.
This is useful mainly for deeper waters and to see better
fish arches in shallow water.
• To show data from a 50 kHz sonar signal, select 50 kHZ.
• To select a specific frequency, select Manage
Frequencies, and enter the frequency.
Turning On the A-Scope
The a-scope is a vertical flasher along the right side of the full-
screen sonar view. This feature expands the most recently
received sonar data so that it is easier to see. It can also be
helpful for detecting fish that are close to the bottom.
From a Sonar view, select Menu > Sonar Menu >
Appearance > A-Scope > On.
Sonar Setup
Sonar Settings
From a Sonar view, select Menu > Sonar Menu > More.
Scroll Speed: Sets the rate at which the sonar scrolls from right
to left.
Shift: Allows you to shift the area for which the sonar will look
for targets. This is helpful to allow you to get a better image
in the focused depth.
Noise Reject: Reduces the interference and the amount of
clutter shown on the sonar screen.
Appearance: Configures the appearance of the sonar screen.
Alarms: Sets sonar alarms.
Advanced: Configures various sonar display and data source
settings.
Installation: Configures the transducer.
Sonar Noise Rejection Settings
From a Sonar view, select Menu > Sonar Menu > More >
Noise Reject.
Interference: Reduces the effects of crosstalk and electrical
interference.
Color Limit: Hides part of the color palette to help eliminate
fields of weak clutter.
Smoothing: Allows the sonar screen to appear more consistent
in deeper water.
Surface Noise: Sets whether the returns near the surface of the
water appear on the sonar screen. Hiding surface noise
helps reduce clutter.
Sonar Appearance Settings
From a Sonar view, select Menu > Appearance.
Color: Sets the color scheme.
Overlay Numbers: Sets the data shown on the sonar screen.
A-Scope: Displays a vertical flasher along the right side of the
screen that shows instantaneously the range to targets along
a scale.
Depth Line: Shows a quick-reference depth line.
Edge: Highlights the strongest signal from the bottom to help
define the hardness or softness of the signal.
Pic. Advance: Allows the sonar picture to advance faster by
drawing more than one column of data on the screen for
each column of sounder data received. This is especially
helpful when you are using the sounder in deep water,
because the sonar signal takes longer to travel to the water
bottom and back to the transducer.
The 1/1 setting draws one column of information on the
screen per sounder return. The 2/1 setting draws two
columns of information on the screen per sounder return,
and so on for the 4/1 and 8/1 settings.
Sonar Alarm Settings
NOTE: Some settings require external accessories.
Select Settings > Alarms > Sonar.
Shallow Water: Sets an alarm to sound when the depth is less
than the specified value.
Deep Water: Sets an alarm to sound when the depth is greater
than the specified value.
Water Temp.: Sets an alarm to sound when the transducer
reports a temperature that is 2°F (1.1°C) above or below the
specified temperature.
Contour: Sets an alarm to sound when the transducer detects a
suspended target within the specified depth from the surface
of the water and from the bottom.
Fish Alarm: Sets an alarm to sound when the transducer
detects a suspended target within the specified depth range
and the specified color range.
Advanced Sonar Settings
From a Sonar view, select Menu > Sonar Menu > More >
Advanced.
Transmit: Stops the transducer from transmitting.
TVG: Adjusts the time-varying gain, which can reduce noise.
Echo Stretch: Adjusts how the targets appear on the screen. If
the echo stretch value is too high, the targets blend together,
and if the value is too low, the targets might be small and
difficult to see.
Bottom Track: Sets the frequency used for determining depth.
Temp. Source: Sets the water-temperature sensor or
temperature-capable transducer as the source for the water
temperature log.
Transducer Installation Settings
From a Sonar view, select Menu > Sonar Menu > More >
Installation.
Transmit Rate: Reduces self-interference. You can increase
the transmit rate to speed up the scroll speed, but this might
also create self-interference.
Transmit Power: Reduces transducer ringing near the surface.
A lower transmit power value reduces transducer ringing.
Filter Width: Defines the edges of the target. A shorter filter
defines the edges of the targets. A longer filters creates
softer target edges, but may also reduce noise.
Transducer Diagnostics: Shows details about the transducer.
Radar
WARNING
The marine radar transmits microwave energy that has the
potential to be harmful to humans and animals. Before
beginning radar transmission, verify that the area around the
radar is clear. The radar transmits a beam approximately 12°
above and below a line extending horizontally from the center of
the radar. Avoid looking directly at the radar, because the eyes
are the most susceptible parts of the body.
Radar 11