Garrett AT Pro User manual

© 2010 Garrett Electronics, Inc. PN 1533300.A.0910
1881 W. State Street
Garland, Texas 75042
Tel: [phone]
Email: [email protected]
Fax: [phone]
AT PRO INTERNATIONAL Owner’s Manual
Owner’s Manual
TM
e powerful, all-terrain solution for locating
deeply buried European coins and artefacts!

AT Pro International™ 1
THANK YOU FOR CHOOSING
GARRETT METAL DETECTORS!
Congratulations on the purchase of your new Garrett AT
Pro™metal detector. This enhanced metal detector has
been specifically designed for use in Europe's challenging
environments.
The AT Pro includes Garrett's exclusive Target ID technology
and patented discrimination features. Two indicator scales
allow you to see the detector’s discrimination setting (Lower
Scale) as well as the analysis of each target (Upper Scale).
In addition, a Digital Target ID scale provides a more specific
target value. The AT Pro also features High Resolution
Iron Discrimination (40 points) for separating desirable
targets from iron junk in cluttered areas, several advanced
audio features and a standard 28x22cm elliptical Double-D
searchcoil engineered for optimum performance in Europe's
more challenging mineralised soils. In addition, the AT Pro
can be operated in a very user-friendly Standard (STD) Mode
or in a more advanced PRO Mode for experienced hunters.
Backed by more than 45 years of extensive research
and development, your Garrett AT Pro metal detector is
the most advanced of its kind in the industry. Whether you
are experienced or a beginner, this machine is well suited
for a wide variety of detecting environments. The AT Pro's
advanced features are designed for the expert treasure
hunter but its Standard Mode can be easily operated by the
beginner.
In order to take full advantage of the special features and
functions of the AT Pro, you are urged to carefully read this
instruction manual in its entirety.

2Garrett Metal Detectors

AT Pro International™ 3
TABLE OF CONTENTS
AT PRO CONTROL PANEL ................................................................... 4
QUICK START GUIDE........................................................................... 5
AT PRO COMPONENTS....................................................................... 6
LIST OF PARTS .................................................................................... 7
ASSEMBLY .......................................................................................... 8
POWERING ON.................................................................................. 11
SEARCH MODES............................................................................... 12
Overview of STD Mode vs PRO Mode........................................ 12
Standard (STD) Detection Modes.............................................. 13
PRO Detection Modes................................................................ 15
Proportional Audio (PRO Mode)................................................. 15
Tone Roll Audio (PRO Mode)...................................................... 18
TARGET ID INFORMATION ................................................................ 19
DIGITAL TARGET ID........................................................................... 20
TONE ID............................................................................................. 21
DISCRIMINATION .............................................................................. 22
Notch Discrimination.................................................................. 22
Iron Discrimination..................................................................... 24
IRON AUDIO ...................................................................................... 27
SENSITIVITY...................................................................................... 30
GROUND BALANCE........................................................................... 31
Automatic Ground Balance........................................................ 31
Manual Ground Balance............................................................ 32
FREQUENCY ADJUSTMENT .............................................................. 33
PINPOINTING .................................................................................... 34
Narrowing the Detection Area ................................................... 36
Coin Depth Indicator .................................................................. 36
Alternative Pinpointing Methods ............................................... 37
HUNTING TIPS .................................................................................. 39
BENCH TESTS................................................................................... 44
UNDERWATER OPERATION .............................................................. 47
CARE AND MAINTENANCE ............................................................... 48
Battery Replacement ................................................................. 48
TROUBLESHOOTING GUIDE............................................................. 50
METAL DETECTING CODE OF ETHICS ............................................. 51
CAUTIONS ......................................................................................... 52
WARRANTY / SERVICE ..................................................................... 53
ACCESSORIES................................................................................... 54
SUGGESTED READING..................................................................... 56

4Garrett Metal Detectors
AT Pro CONTROL PANEL
Battery Level
Indicator
ELIM and NOTCH DISC
Pushbuttons
Use NOTCH DISC (+) or (-) to select
a cursor. Then use ELIM button to set
its discrimination on or off.
SENSITIVITY
Pushbutton
increases or decreases sensitivity.
ON / OFF Power: hold 1 second
to turn power on/off.
MODE: push quickly to toggle
between detection modes.
RESET: hold 5 seconds to restore
factory settings.
Coin Depth
Indicator
indicates depth of
coin-sized target.
Mode
Indicator
Target ID
Legend
indicates
metal types.
Lower Scale
indicates notch
discrimination pattern.
Target ID
Cursor
indicates
probable
target identity.
Digital
Target ID
(also shows
ground balance
settings while in
GND-BAL mode.)
PINPOINT /
Frequency
Adjust
Pushbutton
Press and hold to
pinpoint or use with
SENSITIVITY (+)
or (-) to change
frequency.
Sensitivity
Setting
High Resolution
Iron Discrimination
indicates level of iron
discrimination selected.
Iron Disc
Pushbutton
Use (+) or (-) to change
iron discrimination
level.
Iron Audio
Use to hear
discriminated
iron.
GROUND BALANCE
Pushbutton
Press and hold for fast auto
ground balance or use with
NOTCH DISC (+) or (-) for
manual ground balance.

AT Pro International™ 5
QUICK START GUIDE
1. Install batteries.
The AT Pro operates with four (4) AA batteries which are
already installed by Garrett.
2. Power ON.
Press and release the ON / OFF Power button. The AT Pro
powers on in the last mode used and is ready to search.
(Factory default mode is Coins.)
3. Select Mode.
Use the Mode Pushbutton to select a different detection
mode, when desired.
4. Adjust settings.
Adjust Sensitivity or Discrimination settings, if desired.
5. Begin scanning.
Lower the searchcoil to 2 to 3 cm above the ground and
scan the coil left and right at approximately 1m/second.

6Garrett Metal Detectors
AT Pro COMPONENTS
Control
Housing
S-shaped
Stem
Upper
Stem
Lower
Stem
Search
coil
Handle
Grip
Padded
Arm Cuff
LCD
Screen
Detector
Stand
Pushbutton
Controls
Arm
strap
Spring
Clip

One (1) control housing with
S-shaped stem
One (1) upper stem and one
(1) lower stem connected
One (1) wing nut, two (2)
mounting washers and
one (1) threaded bolt
One (1) 28x22 cm DD
searchcoil
Owner's manual
Warranty Card
Headphones
AT Pro International™ 7






LIST OF PARTS
No tools are required to assemble the AT Pro. Four (4) AA
batteries are included with the detector. The box for your
detector contains the following parts:
If any part is missing, please contact your local dealer.


ASSEMBLY
8Garrett Metal Detectors
1. Align the holes in the mounting washers with the
small posts on the lower stem and press firmly into
place.
2. Slide the searchcoil onto the stem.
3. Insert the threaded bolt through the holes of the
lower stem and searchcoil. Hand-tighten the
searchcoil assembly with the wing nut.
4. Depress the spring clip in the S-stem and insert the
control housing into the upper stem.
1. 2.
3. 4.

AT Pro International™ 9
5. Depress the spring clip in the lower stem and adjust to
the most comfortable operating length.
6. Wrap the cable snugly about the stem with the
first turn of the cable over the stem.
7. Insert the coil connector into the 4-pin connector of
the control housing and hand-tighten.
6.
7. 8.
8. If needed, adjust the arm cuff by removing the screw
on the bottom and moving it to the other hole.
5.

10 Garrett Metal Detectors
9. If desired, attach headphones to the 2-pin connector
of the Control Housing.
Note: Headphones are not required but are desired
by many hunters to hear faint targets. Connecting
the headphones will silence the detector's speaker.
Note: The provided headphones are for dry use only;
see page 54 for optional waterproof headphones.

AT Pro International™ 11
POWERING ON
Switch the detector on with the power button.
Press and release to switch the unit ON and resume hunting
with the same settings used prior to switching the unit OFF.
To turn off the detector, press and hold this pushbutton for
one (1) second (until the detector produces a second beep).
To restore the factory settings, press and hold the power
button for 5 to 10 seconds (until the detector produces a fast
double beep).
ON/OFF Power
and MODE
Pushbutton

12 Garrett Metal Detectors
SEARCH MODES
The AT Pro includes six detection modes: three Standard
(STD) Modes and three Professional (PRO) Modes. It is
recommended to begin searching with one of the Standard
Modes to become familiar with the AT Pro before switching
to the more advanced audio features provided by the Pro
Modes.
Tap the Mode button to scroll through the six modes:
the modes are Custom, Coins or Zero in the STD Mode and
Custom, Coins or Zero in the PRO Mode.
•OverviewofSTDModevsPROMode
In its Standard (STD) Mode, the AT Pro provides a full-
strength audio response regardless of a target’s amplitude.
Many detectorists prefer this consistent, unambiguous, binary
(either on or off) target response. The AT Pro's Standard Mode
operates in this clean, binary response format in which the
target's dominant conductivity is reported by a single tone.
This mode offers "quieter" or more stable operation and is
preferred by many beginners.
For those who want to hear more target information,
Garrett offers a Pro Mode. The benefits of operating in Pro
Mode include the ability to hear a target's size and depth via
the Proportional Audio and conductivity changes via Tone
Roll Audio. Pro Mode also offers faster recovery speed for
separating adjacent targets. The advanced audio features of
Pro Mode are intended for more skilled users who wish to
hear the true signature of targets versus the simpler target
response provided in STD Mode.

AT Pro International™ 13
• ZERO Mode
Designed to detect every type of metal; use
ZERO mode to find all metal items or when the
material of the desired object is unknown. All 12
discrimination pixels are switched on and High-Res
Iron Discrimination is set to 0 (zero)—indicating that
no metal targets have been eliminated.
Switch to the ZERO Mode to aid in locating a
target when its signal is inconsistent. Such signals
could mean the target is made of iron or a trash
target is close to a good target.
STANDARD (STD) DETECTION MODES
In the STD modes, the AT Pro produces a full-strength
binary audio beep to indicate a detected target. Standard
detection mode operation is ideal for learning the AT Pro
because of its consistent audio signals. Detected targets
are heard at the same full-strength beep regardless of their
size or depth.
Three discrimination patterns are available in the
Standard Mode: Zero, Coins or Custom.
Note: These three discrimination patterns are the same
in either Standard or Pro modes.

14 Garrett Metal Detectors
•COINS Mode
Designed to find most types of coins, jewelry, etc.,
while eliminating trash items such as iron and foil.
High-Res Iron Discrimination level has been preset
to 35 to exclude most iron targets. In addition,
one pixel of foil has been excluded. Be aware that
most pulltabs and pieces of tabs have not be
eliminated from detection as these trash items have
conductivities similar to small coins and jewelry.
•CUSTOMMode
This mode can be customized by the operator and
the AT Pro will retain the changes when the detector
is switched off. The factory preset for the CUSTOM
Mode is the same as the ZERO Mode (see previous
page). Begin with this discrimination pattern and
then use IRON DISC and NOTCH DISC pushbuttons
to customize the discrimination settings.
Note: Changes made to the ZERO or COINS modes
will not be retained after the detector is switched
off. (For information on the use of IRON DISC and NOTCH
DISC, see pages 22–26.)

AT Pro International™ 15
PRO DETECTION MODES
Zero, Coins or Custom have the same discrimination
patterns as in STD Mode. In PRO Mode, however, the AT Pro
utilizes its Pro Audio functions—including Proportional Audio
and Tone Roll Audio—to offer more target information.
The Pro Mode audio provides more target information and
faster recovery speed for separating adjacent targets. This
is especially important in areas where good targets may be
scattered amongst iron trash.
Pro Mode audio by its nature creates more audible chatter
than Standard Mode. This is normal because of the additional
sensitivity of Pro Mode. The audio depth can exceed Target ID
depth in Pro Mode so it is possible to hear deep targets that
do not register a Target ID.
Proportional Audio (Pro Mode)
Proportional audio response means that the loudness
of the target's response is proportional to a target's signal
strength. This allows the user to hear subtle changes in a
target’s response. Proportional audio response also allows
the user to better judge a target’s size, shape and depth
and has the additional benefit of faster recovery time for
separating adjacent targets.

16 Garrett Metal Detectors
Shallow coin
Audio Target Response Comparison: Standard vs Pro Mode
Notice the differences in Standard binary audio versus PRO audio in the two
target scenarios above. The binary audio gives a solid, consistent beep for
both the shallow and the deep coin. In contrast, PRO Mode's proportional
audio provides a stronger signal for the shallow coin and a softer signal for
the deeper coin. The actual profile, or signature, of the target’s response is
heard, thereby providing more information.
Deep coin

AT Pro International™ 17
Adjacent targets
Adjacent Targets Comparison: Standard vs Pro Mode
These two adjacent coins would produce one strong signal while in STD Mode.
In PRO Mode, the proportional audio provides two peaks of audio response to
allow the user to identify multiple targets.

18 Garrett Metal Detectors
Tone Roll Audio (Pro Mode)
This feature of Pro Mode provides the user with more
audible target information to help identify targets, particularly
flat iron objects, such as bottle caps and washers. Standard
Mode audio produces a single tone based upon the target’s
strongest signal. For flat iron objects, this single tone is often
the same as a good target. Tone Roll Audio, however, provides
a variance of target tones as the searchcoil approaches and
passes over the target. These varying tones of audio provide
better overall target information and identification.
Bottle cap Coin
While in STD Mode, bottle caps, steel washers and other flat iron objects
often sound like good targets, producing a high tone response. This is
because the bottle cap’s shape and flat surface resembles a coin which
can trick the detector. In PRO Mode, however, the bottle cap will produce a
very distinctive response with multiple tones. As shown, the bottle cap will
produce a distinctive response of Low-High-Low as compared to the coin’s
response of only High tone.
Tone ID Comparison: Standard vs Pro Mode

AT Pro International™ 19
TARGET ID INFORMATION
Target ID Cursor
(Upper Scale)
Target ID Legend Discrimination
Pattern (Lower Scale)
Target ID Legend—Works in conjunction with the Target ID
Cursor to indicate a target's probable identity. Ferrous (iron)
targets will indicate on the left half, non-ferrous targets that
are thin or have low conductivity will indicate in the middle,
and thick or high conductivity targets (e.g. thick silver) will
indicate at the right.
Target ID Cursor (Upper Scale)—The Target ID cursor, in
conjunction with the Target ID Legend, indicates the probable
identity of a detected target. The upper scale consists of
twenty (20) graphic segments for Target ID.
Lower Scale—The lower scale, or Notch Discrimination
Scale, continually indicates the discrimination pattern. The AT
Pro will produce an audible target response for the pixels that
are switched on, and no audible response for those that have
been switched off. The Target ID Cursor will always indicate
all targets.
The discrimination pattern can be adjusted (as described
in the "Discrimination" section).