Garrett Investigator G-500 User manual

SPECIAL NOTICE
The Garrett Investigator G-500 metal detec-
tor is a precision electronic instrument that
utilizes high technology to help locate hidden
evidence, weapons and other metallic
objects of all kinds while giving years of trou-
ble-free service.
NOTE: All you will ever need to know to
operate this detector can be found on Pages
12-16. Later pages simply provide additional
details.
This amazing instrument with its computer-
ized microprocessor-controlled circuitry is
extremely easy to operate. Yet, those who
demand it will find the Investigator G-500
meticulously adaptable to their own personal
style of searching with a metal detector.
This new detector is built to withstand
rugged treatment in the outdoors, but you
should always handle the detector carefully.
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CONTENTS
Assembly 9
Touchpads 12
Graphic Display 14
BASIC INSTRUCTIONS 15
Adjustments - Mode 20
Depth 21
Audio Threshold 22
Headphone Jack 24
Setting Discrimination
(Notch Patterns) 25
Bench Testing 29
Operating Recommendations 32
Electronic Pinpointing 37
Depth Measuring 35
Battery Information 42
Hip Mount Use 47
Searchcoils 49
Recommended Accessories 51
Maintenance 52
Repair Service 54
Recommended Reading 57
Specifications 59
Protect it at all times from mist, rain or blow-
ing sand and keep it as clean as possible.
Trademarks: GTA, Investigator G-500, and
Graphic Target Analyzer are TM of Garrett
Electronics, Inc.
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objects. It offers the professional investigator
added depth and the adjustment precision
available only with computerized microproces-
sor controls. The completely new Graphic
Target Analyzer (GTA) display offers target
acceptance, rejection and other data never
before available.
Press the POWER touchpad and begin hunt-
ing immediately without interference from
ground minerals. As the world's most intelligent
detector, the Investigator G-500 is preset at the
factory to begin operations in an All Metal
detection mode. Of course, you can easily
adjust the instrument to change discrimination
in that mode or a second program offered for
your convenience in searching.
When you find a cartridge-sized metal target,
press the PINPOINT pad to discover its exact
location and depth. Your Investigator G-500 is
equipped with an 8 1/2-inch Crossfire search-
coil. Other accessories are listed on Page 42.
Welcome again to the Garrett metal detecting
TO THE OPERATOR
As the operator of a Garrett Investigator G-
500, you join a worldwide fraternity of security
and law enforcement officers who use Garrett
detectors as crime-fighting weapons.
Garrett is famed throughout the world for man-
ufacture of the SuperScanner hand-held and
Magnascanner walk-through detectors.
Lawmen and women have used their Garrett
instruments to find guns, knives, bullets and
weapons and contraband of all types. You too
can be more efficient and successful with the
Investigator G-500 detector. This Operator's
Manual will describe the basic functions of the
detector and explain how you can use it to
locate all types of metal objects.
The G-500, whose microprocessor-controlled
circuitry has already been acclaimed and
proven through countless hours of field use, is
unparalleled in the simplicity of its ability to
locate evidence, weapons and other metallic
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ASSEMBLY
The Investigator G-500 is shipped complete in
one carton:
• Control Housing
• Upper & Lower Stems
• Crossfire Searchcoil
• Parts Envelope (Contents listed
below)
Make certain all of these parts are included
and are undamaged. Immediately report short-
ages or damages to your dealer. Follow these
assembly instructions. No tools are required.
Hand pressure will be satisfactory for all tight-
ening.
1. Open the clear plastic envelope which con-
tains two (2) spring clips, two (2) knobs, two (2)
washers and one (1) threaded bolt. Compress
the button ends of one spring clip and insert,
button-end first, into the lower stem of your
detector so that the buttons pop out of the
holes. Insert the other clip into the stem con-
nector at the rear of the electronic control
fraternity. In selecting an Investigator G-500
you have taken the advice of experienced law
enforcement officers. Now, use one of the
world's most capable automatic metal detec-
tors to let Garrett help you fight crime!
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4. As shown, wrap searchcoil cable securely
around stem and connect to detector. The first
cable turn goes over the top of the stem. The
cable should be snug but still slightly loose so
that the angle of the searchcoil can be
changed easily, when required. To connect
cable to the detector insert the cable connec-
tor, as shown below, into the housing connec-
tor and rotate collar clockwise until secure
(approximately four turns). Hand tighten only.
Never use any kind of lubricant.
The Investigator G-500 is equipped with eight
(8) AA batteries.
housing. The two sets of buttons will enable
you to secure the top stem to the control hous-
ing and adjust length of the overall stem.
2. Attach the lower stem to the searchcoil by
inserting the two rubber washers onto this
stem and slipping the searchcoil onto it. Place
the threaded bolt through the holes in the con-
nector and hand-tighten the knobs. Use no
tools. Insert upper stem into the control hous-
ing.
3. Depress the buttons in the lower stem and
insert it into the upper stem. Let buttons pop
into the holes to achieve desired stem length.
The third set of holes from the end is most
commonly used.
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Set DISC
This control pad in conjunction with the cursor
of the Upper Scale governs the Discrimination
Segments on the Lower Scale of the LCD
which determine discrimination notches. If a
segment is shown, pressing this pad will elimi-
nate it. If it is not shown, pressing this pad will
display it.
PINPOINT
Activates the pinpointing function and causes
depth of cartridge-sized targets to be shown on
the Lower Scale.
LAST MODE
Alternately switches operations between
Modes A and B.
- & +
1. Adjusts levels of threshold and depth
2. Moves cursor in Upper Scale when setting
discrimination
CONTROL TOUCHPADS
POWER
1. Turns detector on;
2. Turns detector off;
3. Resets detector to factory calibration.
Set DEPTH (Sensitivity)
Permits using the + and - touchpads to regu-
late depth (sensitivity) of the detector. See
Set AUDIO
Permits using the + and - touchpads to regu-
late the audio threshold.
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BASIC INSTRUCTIONS
The next four pages of this Operator's Manual
contain basic operating information about the
Investigator G-500 . Although this detector is
among the most advanced instruments manu-
factured today, it is the simplest to operate of
all the detectors that have ever been designed
and produced by Garrett. You can begin
searching with it immediately. No special
instructions are needed beyond what's includ-
ed in the next four pages. Start finding evi-
dence and hidden weapons right now!
To Begin
1. There are no dials to turn no controls to
adjust. Just grasp the handle of your G-500,
and lower the searchcoil to a level about one
foot above the ground.
2. Press and release the POWER touchpad.
After you hear two beeps, the Investigator G-
500 is ready for detecting in Mode A.
Whenever the detector is turned on, it will
always begin operating in this mode which is
GRAPHIC DISPLAY
Metal ID Guide
At top of the control panel various metals and
metallic items are specified for use with the
Upper Scale to help identify targets.
Upper Scale
1. Indicates target discovered
2, Indicates sensitivity/threshold
3. Indicates maximum pinpoint signal
4. Indicates cursor location
(For changing discrimination patterns)
Lower Scale
1. Indicates discrimination (notch patterns)
2. Indicates coin depth when pinpointing
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ond. Maintain your coil at a height of one to two
inches above the ground. Detection of a metal
target will be indicated by an increase in sound
and visual indications on your Graphic Target
Analyzer (GTA).
Discovery
Locate your target precisely by scanning back
and forth to locate the loudest signals. The
Upper Scale of the Graphic Display will indi-
cate a detected target as shown below. This
indication cursor remains for five seconds or
until a new target is detected (whichever
comes first). The Metal ID Guide (below
Graphic Display) helps to identify targets.
set at the factory to detect all metallic targets.
NOTE: Only a light touch is all that is ever nec-
essary to activate any touchpad.
3. As noted, Mode A of the Investigator G-500
offers no discrimination. It will detect all metal
targets.
Mode B discriminates against some targets
made of junk metal, which means that the
detector will sound no signal when such tar-
gets are detected. (Every target detected is
ALWAYS shown by the cursor on the Upper
Scale.) Mode settings can be changed easily,
but you may never want to do so!
It is recommended that you not attempt to use
any discrimination for the first few hours of
searching.
Scanning
Swing the searchcoil back and forth in front of
you in a straight line. Keep the searchcoil mov-
ing at a rate of about one to two feet per sec-
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could ever find. The array of data presented on
the Graphic Display makes you more aware of
all these targets. Additional operating experi-
ence with this detector will give you a better
understanding of how its Graphic Display com-
bines with the audio to present target signals.
You will quickly master your new detector
because of its simplicity. Yet, the Investigator
G-500 with controls based on patented micro-
processor technology has more discrimination,
mode sensitivity and effectiveness than any
other detector ever manufactured.
To turn off your detector simply press and
release the POWER touchpad. Operating bat-
tery power is disconnected.
Special Note on Settings
If you are ever unsure about the settings of
your detector, just press and hold the POWER
touchpad for 10 seconds (or, until you hear a
single "beep"). This will restore manufacturer's
settings and return your Investigator G-500 to
its factory-set All Metal mode.
JUNK TARGETS
Because your Investigator G-500 in its facto-
ry-set Mode A detection mode responds audi-
bly to all metal items, you will probably detect
numerous "junk" items. You'll soon learn, how-
ever how these targets respond with a quick,
sharp sound not like the clear, strong signal of
a weapon or shell casing. Before you dig up
some of the targets that make irregular audio
"blips," see how they register on the Upper
Scale of the Graphic Display in relation to the
Metal ID Guide. Speed up your searching by
learning to recognize as many of these junk
targets as you can.
You may have encountered an occasional
instance when the Graphic Display seemed to
be presenting conflicting information. This
probably occurred when your detector was
attempting to analyze two or more different tar-
gets beneath its searchcoil. Don't be alarmed.
This condition happens with all detectors, but
the GTA discovers vastly more targets than
old-style instruments with their limited circuitry
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Depth (Sensitivity)
When the DEPTH touchpad is pressed, the
display screen will appear as shown in the dia-
gram above (with factory setting at approxi-
mately 75% as indicated on Upper Scale). You
can use the + and - touchpads to adjust the
depth to which your detector will operate effec-
tively. These changes will be shown on the
Upper Scale.
Although the instrument's maximum depth
may be desired, this is usually not feasible
because of the type of soil over which you are
scanning, electromagnetic or power line inter-
ference and other conditions. Ground mineral-
ization and other considerations can inhibit the
detector's ability to interpret target information.
This control option permits you to achieve
maximum detection depth possible in relation
ADJUSTMENTS
Mode
Whenever your detector is turned on, it will
begin operating in Mode A (shown on the
Graphic Display). This is an all metal mode
with no discrimination. You can change to an
alternate discrimination program simply by
pressing the LAST MODE touchpad. Mode
selection will always be illuminated on the
Graphic Display.
When you first press the POWER touchpad,
threshold, depth and discrimination will be at
levels preset at the factory. Any or all of these
operating levels can be easily changed.
The Investigator G-500 permits a user to
"design" personal discrimination patterns
through use of the touchpads. Many
Investigator G-500 owners will never want to
change patterns and will hunt only in either of
the factory preset modes.
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You can search silently or at any level of con-
stant sound. It is recommended that you
always operate the instrument at a minimum
level of sound. You can hear the audio
increase sharply whenever a target is encoun-
tered. Also, you will be able to hear even the
faint signals that sometimes occur on tiny tar-
gets or deeply buried objects. When head-
phones are used, it will usually be necessary to
decrease the threshold level since sound is
more audible through headphones.
After you have made audio adjustments, press
AUDIO to reenter your previous operating
mode.
Battery
The Investigator G-500 will indicate accurately
the condition of standard (carbon or alkaline)
or NiCad rechargeable batteries with the four
squares after BATT.
to existing environmental conditions.
Press (+) to increase detection depth. Press
(-) to decrease.
A single touch and release adjusts the level in
a small increment. A continuous pressing
results in a continuous adjustment. The Upper
Scale on the Graphic Display indicates 18 lev-
els that are available. Minimum depth is 25%.
When you have made your adjustment, press
DEPTH again to reenter an operating mode.
Audio Threshold
When the AUDIO touchpad is pressed, the dis-
play screen will appear (diagram below) with
factory setting indicated on the Upper Scale.
Use the + and - touchpads to adjust the thresh-
old, which is the level of sound that is constant-
ly being produced by the Investigator G-500 as
it is being scanned.
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noise of people and/or traffic is excessive.
SETTING DISCRIMINATION
(Selecting Notches)
Many investigators will never require any type
of discrimination. They will be searching for all
metallic targets that might prove to be evi-
dence or looking for any metallic object that
might turn out to be a buried weapon. Still, this
detector offers precise controls that enable an
operator to tailor a detection mode to his or her
specific requirements by setting accept/reject
"notches."
The Lower Scale of the Graphic Display con-
tains 24 segments. Those that are illuminated
(or, displayed) represent conductivities of the
targets that will be detected (with an audible
signal sounded) in the individual operating
modes.
In Mode A, for instance, all 24 segments are
shown, which indicates that every metal target
will be accepted and recognized by the
Additional Information
Any personal preference adjustments you
have set in the Investigator G-500 with the var-
ious operating functions will be retained when
the detector is turned off. Because ground
and/or atmospheric conditions can vary from
place to place, it may be necessary for you to
readjust DEPTH (Sensitivity) occasionally.
Remember!
You can restore instantly the precise factory-
set levels of all its controls. Just hold down the
POWER touchpad for approximately ten (10)
seconds until you hear a "beep."
HEADPHONE JACK
The headphone jack on the Investigator G-500
is located at the rear of the removable battery
pack under the armrest. Headphones are a
valuable accessory for any metal detector to
mask interference from outside noise. They
permit you to hear small and deep targets that
might be missed when using only audio from
the detector speaker. Headphones are particu-
larly essential when you are hunting where
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Lower Scale segment corresponding to the
particular target to be detected or ignored.
Check to make certain there is an appropriate
cursor on the Upper Scale of the Graphic
Display. Then press DISC depending upon
your discrimination choice for this specific tar-
get.
Note: Discrimination notches you have creat-
ed in Mode B will not affect discrimination in
the other mode. Each time the detector is
turned off your Mode B DISC accept/reject dis-
crimination patterns will be retained. All selec-
tions will be lost when you return your detector
to factory-set detection calibrations by press-
ing and holding the POWER touchpad.
There are numerous reasons why you would
want to accept or reject specific targets:
• You may be looking for only one item D a cer-
tain cartridge, for example. You can program
the Investigator G-500 to reject all other types
of metal targets.
Investigator G-500. Specific "notch" patterns
can be created in Mode B by adding or remov-
ing illuminated segments.
There are two methods of setting discrimi-
nation in Mode B:
First Method: Pass the searchcoil over an
object to be accepted or rejected as a target or,
pass the particular target across the face of the
coil about two inches from its surface. If the
segment is displayed on the Lower Scale of
the GTA, that particular target will be detected.
If you wish to reject that type target, press the
DISC touchpad. The segment will disappear,
creating a "reject notch."
If the Lower Scale segment is not displayed,
press the DISC touchpad to illuminate it, creat-
ing an "accept notch," and your GTA detector
will begin detecting targets represented by that
segment.
Second Method: Press the + and - touchpads
to position the Upper Scale cursor above the
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BENCH TESTING
This technique will enable you to test typical
metallic items and to learn about the discrimi-
nating capabilities of the Investigator G-500
before taking it into the field or trying to pattern
your own discrimination notches.
Place your detector on a non-metallic, prefer-
ably wooden, surface with the searchcoil at
least three feet away from all metal. Make cer-
tain you are wearing no rings or jewelry on
your hands or arms that could be detected.
Turn the detector on and adjust the audio con-
trol for threshold sound. The following tests
should be performed with the searchcoil per-
pendicular to the bench:
• You may be hunting in an area where you are
plagued with a specific type of trash. You can
reject just this type of trash metal and continue
to hunt with no other discrimination, detecting
all other metal.
• Just make certain that a potential target does
not fall within any trash segment you have cho-
sen for elimination.
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• Be methodical. Keep written records of
results and use them when searching for evi-
dence or hidden weapons.
• Select Program A and note that all 24 Lower
Scale segments are displayed, denoting no
discrimination. Bring various metallic targets
across the bottom of the coil at a distance of
about two inches. Each target will cause the
sound to increase, which represents non-dis-
criminating operation. Use good targets (gun,
knife, cartridge, etc.) as well as trash items like
a pulltab, bottlecap, etc.
• Use the LAST MODE touchpad to switch to
Program B and begin to experiment with the +,
and DISC touchpads. Note which of the 24
segments are illuminated by the Upper Scale
cursor as you identify various targets. Try to
imagine how these targets will affect your
search for other types of evidence or weapons.
Possibilities are truly countless.
• Experiment with the LAST MODE touchpad
to switch between detection modes and look
for MODE A or B to be illuminated on your
Graphic Display. Practice setting discrimina-
tion notches to eliminate specific targets.
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steadily in a straight line while you walk at a
pace that is comfortable. Be methodical. Do
not skip any areas. Overlap each scan sweep
at least 25% of the searchcoil's width. Wear
headphones for greater sound perception and
concentrate on your scanning.
Target Identification
Target ID and/or conductivity classification of
the last target over which the searchcoil
passed will be indicated on Upper Scale of the
Graphic Display. In many cases the type of
metal can be determined by using the ID
Guide. Encrustation or patina and sometimes
ground minerals, may affect conductivity of the
item, resulting in improper classification.
Some targets, particularly flat pieces of iron
may produce different readings depending on
the angle at which the searchcoil passes over
the object. This is normal and can even be
helpful in identifying iron objects.
FIELD OPERATING
RECOMMENDATIONS
As you walk, scan the searchcoil from side to
side in a straight line in front of you. (See photo
on Page 14.) Move your searchcoil at a rate of
about one to two feet per second, holding it an
inch or two above the ground. When you are
searching in an All Metal mode with no discrim-
ination, detection of any metal target will be
indicated by an increase in sound as well as on
the Graphic Display.
Searchcoil Height
Because of the sensitivity of the Investigator
G-500 and its Crossfire searchcoil, it is not
necessary to operate with the searchcoil
touching the ground. The recommended oper-
ating method is to hold the coil about one or
two inches above the ground.
When scanning, do not hurry. Scan the search-
coil at a speed of about one to two feet per
second. Move it back and forth slowly and
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Move it around slightly, and maximum sound
will be heard when the target is directly
beneath the center of your searchcoil. This
increase will be further reflected in the Upper
Scale of your Graphic Display. Illumination of
the scale's segments, from right to left, will indi-
cate how close you are to your target.
For most effective electronic pinpointing place
the searchcoil on the ground directly above
your target. Press and hold the PINPOINT
touchpad. Scan back and forth across the tar-
get, maintaining searchcoil contact with the
ground. You will notice an even more distinct
audio sound when the target is directly
beneath searchcoil center.
You can also watch the Upper Scale illuminate
from right to left to indicate signal strength.
Maximum reading attained toward the left will
indicate exact target location.
Depth Measuring
Pinpoint targets as directed above. After com-
pleting the pinpoint operation (maximum read-
Recovery
Locating your target precisely will enable you
to recover it quickly by digging the smallest
hole possible. This is accomplished first by pin-
pointing. You can then utilize another function
of the Investigator G-500 for measuring depth.
Pinpoint targets by first drawing an imaginary
"X" on the ground with the searchcoil at the
place where maximum sound occurs. You'll
notice that the searchcoil must be moving
slightly and that you cannot maintain detection
sound with the searchcoil held completely still
above your target. This is called Manual
Pinpointing, and it is satisfactory for many
operators.
There is another more exact method of pin-
pointing, however...
Electronic Pinpointing
Precise pinpointing is an important capability of
your Investigator G-500. When you press and
hold the PINPOINT touchpad, the searchcoil
can remain steady, directly over your target.
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This is a technique that you will come to like as
you use it more often.
Erratic Sounds
When a metallic object is accepted, the detec-
tor's speaker or headphone sound will, of
course, increase from your audio threshold
level. Some rejected targets, however, may
cause the audio to "break up" or sound erratic.
This is generally a response to shallow trash
targets and can be remedied by raising the
height of your searchcoil when scanning.
Setting Depth
Garrett engineers designed your Investigator
G-500 for maximum detection depth power,
but you may not always be able to operate at
100% depth just as you rarely can (or, even
want to) operate your automobile at 100% of
its speed capacity. Outside electromagnetic
interference, irregular ground mineralization
and other environmental conditions may some-
times require that you operate at reduced
detection depth even as low as 25%.
ing on the Upper Scale) and while still pressing
the PINPOINT touchpad, check the Lower
Scale (see illustration above) to determine
depth of the target in inches.
Measurement is based on targets about the
size of a .38-caliber shell casing. Depth meas-
urement may vary on smaller or larger targets.
Last Mode
Use of this touchpad can be particularly helpful
while scanning because it effectively converts
your Investigator G-500 into a dual-mode
detector. Pressing and releasing the touchpad
makes it easy to alternate between the A and
B programs. You can search with no discrimi-
nation in one program to detect all targets, and
then check your target by switching to Mode B
in which a discrimination pattern is notched.
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metal from the ground.
Next, select targets such as .22-caliber bullets,
.38-caliber shell casings, a dummy pistol, a
knife, a bottlecap, a nail and a pulltab. Select
also a pint jar filled with scrap copper and/or
aluminum metal, a long object such as a foot-
long pipe and a large object such as a gallon
can. Bury all these objects in rows about three
feet apart and make a map showing where and
how deeply each item is buried.
Bury shell casings and bullets at varying
depths, beginning at one inch. Continue, with
the deepest buried about six inches. Bury one
at about two inches but stand it on edge. Bury
a shell casing at about two inches with a bot-
tlecap about four inches off to one side. Bury
the bottlecap, nail and pulltab separately about
two inches deep.
Bury the jar at twelve inches to the top of its lid.
Bury the pipe horizontally three or four inches
deep. Bury the gallon can with the lid two feet
below the surface. Remember to make a map
Don't worry about losing "deep targets!" You
won't lose anything since you can always oper-
ate as deeply as conditions permit. Attempting
to operate above a level that permits a quiet
and stable audio threshold may actually cause
you to miss deep targets that you would have
found had you not "pushed" the detector.
Another point to remember is that when you
are operating with Depth set below the maxi-
mum because "less-than-perfect" environmen-
tal conditions, you will have additional detec-
tion power whenever it is possible for you to
use it.
Test Plot Construction
As you operate and use your Investigator G-
500, you will quickly grow more proficient in its
use. It is suggested that you develop a "test
plot" to hear how various targets will "sound" to
the detector or how they will appear on its LCD
display. This Test Plot will also prove invalu-
able in training others to use metal detection
equipment. After you select the area for your
test plot, scan it thoroughly and remove all
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