18 Garrett Metal Detectors
AT Gold
™
19
Press and release the GND BAl pushbutton again to exit
Manual Ground Balance mode.
you may want to use the Manual Ground Balance function
to ground balance slightly positive to enhance detection of
small targets or balance slightly negative to reduce detection
of "hot rocks," terra cotta and clay bricks. Adjusting the
AT
Gold
to be ground balanced slightly positive may produce a
weak but audible response from the ground as the searchcoil
is lowered. Maintaining a level coil swing at a constant height
above the ground will minimize this ground response.
Typical Ground Balance Ranges:
65–99: Highly ferrous (ferrous oxide minerals, black sands,
magnetite, hot rocks)
50–65: Highly ferrous, slightly conductive (hot rocks, terra
cotta)
30–50: Moderately to highly ferrous (red and iron-bearing
clays, most terra cotta, hot rocks)
0–30: light to moderately mineralized (brown and yellow
clays, etc.)
Adjustable Ground Balance Window™—
experienced
prospectors recognize that mineralized ground is often a
mixture or matrix of different soils, rocks, and pockets of
concentrated mineralization, each possibly requiring a slightly
different ground balance setting. In such cases it may not
be possible to find a single ground balance setting that
simultaneously balances to the different ground components.
This is not a result of limited ground balance resolution; rather,
this is due to localized variations in the ground minerals.
For conventional detectors operating in All Metal Mode,
these ground variations can produce subtle audio responses
that reduce the operator’s ability to discern faint signals,
resulting in missed targets. even detectors with continuous
ground tracking cannot compensate for these localized
ground variations.
Garrett has addressed this issue with its adjustable
Ground Balance Window which allows the operator to
effectively “spread” the ground balance setting in order to
simultaneously ground balance to a range of values. This
smoothes out the audio by reducing the subtle ground
responses and allows the operator to hear those faint targets.
To access this feature, press and release the GND BAl
button to enter Manual Ground Balance mode. use the (+)
or (-) IrON DISC buttons to adjust the GB Window between 0
and 6 as displayed on the lCD above IrON DISC. Press and
release the GND BAl button again to exit this mode. Note:
adjustments to the GB Window take effect only after exiting
Ground Balance mode and apply only to the All Metal Mode.
To optimize the setting, switch to All Metal Mode, ground
balance the detector, and set the GB Window to zero or a
small value. Then exit to All Metal Mode, sweep the coil
Ground Balance
Window setting
GND
BAL
Pushbutton
Use IRON DISC
pushbuttons (while
in Ground Balance
mode) to change
Ground Balance
Window
