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Teknetics T2 Revision 4 Operating Manual
Teknetics T2 (revision 4 manual)
Professional Metal Detector
Comprehensive Operating Manual and Guide to Metal Detecting
The Teknetics T2 TM is a new high-performance multi-purpose professional grade metal
detector. It utilizes the latest advances in electronic technology, and its functional design
represents the leading edge of the metal detector engineering art. The T2 is easier to learn
to use properly than other comparable metal detectors. Its combination of light weight and
balance provides comfort unmatched by any other detector in its price range. Its most
popular uses include coin-shooting, relic hunting, and gold prospecting.
PRODUCT FEATURES
* Simple, easy-to-use controls
* Large LCD screen with target identification display
* Straightforward menu-driven user interface
* Bar graph readout of ground mineral concentration
* Trigger-actuated FASTGRAB tm ground canceling with manual override
* Waterproof 11-inch open-frame BiAxial tm searchcoil
* Single-Filter All Metal mode for maximum detection depth
* Double-Filter Discrimination modes for searching in trashy areas
* Trigger-actuated target pinpointing with variable audio pitch
If you have any questions, or need assistance with your metal detector,
Call 1-800-413-4131, and ask for Teknetics Customer Service.
TABLE OF CONTENTS
Quick-Start ....................... .. 3
Mechanicals
Assembly Instructions ............ .. 4
Batteries ........................ .. 5
Arm Rest adjustment ............... .. 5
Using Headphones (not included) .. .. 5
Introduction to the Teknetics T2
General information ............... .. 6
Controls .............. .........7
Menu System ....................... .. 8
Ground Cancellation ....... 9 & 10
All Metal Mode .................... .. 11
Discrimination Mode ............... .. .12
LCD Visual Display ................ .. 13 –15
Numeric Target Identification .... .. .13
Probable Target Identification .... .. 14
Target Depth ..................... .. .14
G.C. Phase ....................... .. 14
Settings ......................... .. 14
Messages .........................14
Bar Graph ........................15
Battery Indicator ................ .. 15
Capabilities & Limitations ........16 & 17
Tips & Techniques
Search Techniques
How to sweep the searchcoil ...... .. 18
Pinpointing targets .............. .. 18
Estimating target size and depth ..19
False signals and "chatter" ....... .. 19
Adjusting Sensitivity ............ .. 21
Tips on ground canceling .......... .. 22
Detecting Activities
Coinshooting ...................... .. 23
Relic Hunting ..................... .. 23
Gold Prospecting .................. .. 24
Cache Hunting ..................... .. 26
Shallow water hunting ............. .. 26
How metal detectors work .......... .. 27
First Texas Products Warranty .... .. 27
2
QUICK START
Start using your T2 right out of the box
1. Assemble the detector (see instructions beginning page 4).
2 Install four "AA" alkaline batteries. All positive terminals point up.
3. Turn the knob "under the elbow" fully clockwise.
This turns the machine on and sets audio volume to maximum.
4. When first turned on, the T2 starts out in the Discrimination mode, with:
Sensitivity preset to 60
Discrimination Level preset to 10
Number of Tones preset to function-1
Sweep the searchcoil from side to side, parallel to the ground. Keep the searchcoil
moving over the ground. If you stop moving the search coil, the sound will also
stop. Probable target type will be indicated on the LCD screen.
5. If the searchcoil is not in motion and not close to metal, the detector should be
silent.
6. If you experience false signals from electrical interference, from the soil itself, or
from lots of trash metal, press the Menu button.
Sensitivity will be highlighted.
Rotate the Settings knob to the left (counterclockwise),
Reduce the sensitivity setting until the false signals go away.
After about 5 seconds, the machine will exit the menu and return to
normal operation.
7. Toss a coin on the ground and sweep back and forth over it a few times to get a
feel for how the machine responds.
8. You are now ready to search.
9. Pull the trigger switch with your index finger to make recovering a target much
easier.
When the trigger is pulled....
the searchcoil need not be in motion to detect an object
the 2-digit numeric display indicates approximate target depth, in inches
3
ASSEMBLY
1. Remove all components from box.
2. Attach search coil to lower rod (part with plastic extension) by lining up the holes.
Push coil knob through hole and tighten knob gently.
You will tighten up the coil knob later.
3. Insert smallest rod into upper rod (upper rod holds detector body).
Turn locking collar counter-clockwise to open up.
Push in pin on small rod.
Slide small rod into upper rod.
Click pin into hole and tighten locking collar firmly clockwise.
4. Push lower rod into small rod as follows:
Turn locking collar counter-clockwise to open up
Push in pin to allow rod to slide in.
Slide lower rod in.
Click pin into any hole.
5. Remove velcro strip from lower rod.
6. Wrap cable around stem as follows:
Leave some slack in cable at base of lower rod.
Feed cable into 4"-long slot in plastic piece on lower rod.
Secure cable at base of rod with velcro strip.
Wrap cable loosely around entire stem up to bent part of upper rod.
You will re-wrap the cable later after sizing the rods to your height.
7. Push cable into connector on back of housing.
Do not twist the cable or plug. Turn knurled cap nut only.
8. Tighten knurled cap nut by hand to secure cable connection to housing.
Do not twist the cable or plug.
9. Adjust to your height:
Hold detector with your arm in the armrest.
Place searchcoil flat on the ground with back edge of coil 6" in front of your
toes.
Click pin on lower rod into nearest hole.
Firmly tighten locking collar to secure lower stem.
10. Attach cable to top of rod with upper Velcro strip
11. Tighten up coil knob to keep searchcoil from flopping.
12. Insert batteries.
The batteries are all installed with the positive terminals pointed upward.
After establishing a comfortable length, firmly tighten the locking collars on the rods to
prevent the tubes from rattling.
If the searchcoil appears crooked with respect to the pole, loosen both locking collars and
re-adjust. Hold each of the lower poles in the counter-clockwise position as you tighten the
locking collars.
4
MECHANICALS
BATTERIES
The T2 uses four "AA" batteries. Use ALKALINE batteries for best performance.
Rechargeable batteries may be used. Expect 40 hours of service in the field with one set of
ALKALINE batteries.
If you use rechargeable batteries, good-quality NiMH (nickel-metal-hydride) batteries are
recommended. They will usually deliver over 25 hours of service without recharging, but
when they start running low, they die suddenly with little warning.
All 4 batteries are installed with the positive terminals facing upward.
The LCD screen shows battery condition on the right.
ARM REST
The arm rest WIDTH and POSITION are both adjustable.
Arm Rest Width: The sides of the arm rest can be bent inward and outward.
To best stabilize the detector to your arm and body movement, squeeze the sides of
the arm rest around your forearm. For a very secure fit, some users prefer to bend
the arm rest in tightly against the forearm such that you pry the sides loose each
time you place your arm into the arm rest.
Arm Rest Position on Pole: Remove the two bolts to position the arm rest farther forward
or back, to adapt to your individual length.
- To re-insert the bolts, spin and twist them into place.
-- Insert both bolts completely through both sides of the bracket before attaching
the nut to the opposite side.
-- For maximum stability, the bolts fit very tightly into the holes; you may
have to wiggle each one a bit to push it through the holes.
- After reinserting the bolts, tighten them very securely. As you swing the
detector from side-to-side, you want the bolts tight enough so that you do not
feel any movement between the pole and arm rest mounting bracket.
If you notice unwanted movement while swinging detector, check the tightness
of the locking collars.
HEADPHONES (not included)
The T2 is equipped with a standard 1/4 inch stereo headphone jack at the rear of the unit,
located under the elbow as you hold the detector for use. Any headphone with a 1/4" stereo
jack will work. Mono headphones will not work.
Using headphones improves battery life, and prevents the sounds from annoying
bystanders. It also allows you to hear subtle changes in the sound more clearly, particularly
if searching in a noisy location.
For safety reasons, do not use headphones near traffic or where other dangers, like
rattlesnakes, are present.
5
Introduction to the Teknetics T2
HIGH PERFORMANCE The Teknefics T2 is a multi-purpose high-performance
computerized metal detector. It has the high sensitivity and ground cancellation features
needed for professional gold prospecting, the discrimination responsiveness needed for
serious relic hunting under difficult conditions, and visual target ID considered essential in
searching for coins. The ground cancellation system can be adjusted to allow searching salt
water beaches. The T2 operates at 13 kHz for good sensitivity to natural gold and jewelry
as well as to coins. The T2 comes with an 11 inch elliptical bi-axial searchcoil for
maximum detection depth in mineralized soils.
USER COMFORT The T2 is among the lightest and best balanced of all high-
performance metal detectors, so you can hold and swing it almost effortlessly. The arm
rest position is adjustable to fit your arm. The grip is durable high-friction foam elastomer,
comfortable in any kind of weather. The controls are conveniently located and easy to
learn how to use. Locking collars on the tubes eliminate rattling.
EASY-TO-USE & INFORMATIVE INTERFACE The entire menu is always visible on
the LCD display. The LCD display indicates the electrical signature ("target I.D.") of the
detected metal object. The display provides continuous information on battery condition
and on ground mineralization (which affects detection depth). Help messages are
automatically displayed on the lower right corner of the display when necessary.
LOW OPERATING COST The K2 is powered by four "AA" alkaline batteries, which
will typically last for more than 40 hours of use before needing replacement.
CONTROLS
ON-OFF & VOLUME Knob (Under the elbow)
This knob turns the machine on or off, and controls speaker volume.
Knob position has no effect on detector's sensitivity or susceptibility to noise from
electrical interference.
MENU Pushbutton (On right of the front panel)
Push the MENU button to:
1. Step through the menu selections on the display.
Upon each push of the button, the next menu selection will be highlighted.
The SETTINGS knob allows you to change values for the highlighted selection.
2. Recall the last setting which you adjusted.
After you have adjusted a setting, an arrow will remain highlighted next to this
menu selection. One push of the button will recall that selection and display the
stored value.
This recall function is useful for a value you want to adjust frequently, such as the
ground cancellation value.
SETTINGS Knob (On the left of the front panel)
Rotate the SETTINGS knob to:
1. Change the setting (or value) of the highlighted menu selection you have chosen.
2. Select operating MODE when positioned at the top of the menu.
When used to switch back and forth between the All Metals mode and
Discrimination mode, the detector changes modes as soon as the corresponding
selection is highlighted. The All Metals mode is used to detect all metal objects,
including small or deep objects. Use the Discrimination mode to ignore trash metal
such as nails, foil, or pull-tabs.
TRIGGER SWITCH (Under the display in front of your hand)
While the trigger is pulled back, metal objects are temporarily detected without the need
for searchcoil motion. This aids in pinpointing the exact location of objects which were
found while searching in the All Metals or Discrimination Mode.
When the trigger is pushed forward, FASTGRAB automatic ground cancellation is
activated. The internal computer measures the magnetic properties of the soil in order to
cancel interference from naturally-occurring minerals in the ground. After the detector
measures the soil in this manner, the detector then uses this information to control
operation in both the All Metal and Discrimination search modes.
7
THE MENU SYSTEM
The entire menu is printed on the LCD display. The display highlights the mode and
settings which are in use.
There are two search modes, All Metal and Discrimination. To change between search
modes, the top line of the menu system must be highlighted. Press the MENU button until
the top line of the menu is highlighted. When either All Metal or Discrimination is
highlighted, rotate the SETTINGS knob to change between the two modes.
Each search mode has three adjustable function settings:
ALL METAL: Sensitivity, Hum Level, and Manual Ground Cancellation.
DISCRIMINATION: Sensitivity, Discrimination Level, and Number of Tones.
To select a function, push the MENU button and continue pushing to move to the function
you want. The word SETTING will pop up on the display above the menu, and the
present setting of that function will be displayed as a number.
To change a setting, rotate the knob.
To increase a value, rotate to the right (clockwise)
To decrease a value, rotate to the left (counterclockwise)
If you select a function and do not make a change to that function after 5 seconds, the
detector will exit the menu system automatically, and resume normal operation.
If you press the MENU button or rotate the SETTINGS knob while the machine is in
normal operation, the user interface will return to the last menu feature setting. This
feature allows you to have quick access to a function that you want to adjust frequently.
8
GROUND CANCELLATION
What is Ground Cancellation?
All soils contain minerals. These ground minerals are often tens or hundreds of times as
strong as the signal from a desired buried metal object. The magnetism of iron minerals,
found in nearly all soils, causes one interfering signal. Dissolved mineral salts, found in
some soils, are electrically conductive, causing another interfering signal.
Ground Cancellation is the process by which the metal detector cancels the unwanted
ground signals while leaving signals from buried metal objects intact.
When the detector is calibrated to the actual soil condition, the result will be deeper target
detection, quieter operation, and more accurate target identification. This calibration, or
Ground Cancellation, can be accomplished automatically using the detector's internal
computer, by pushing the Trigger Switch forward, or manually in the All Metal menu.
Both automatic and manual ground cancellation settings carry through into both All Metal
and Discrimination modes. In Discrimination mode, the ground signal is generally
inaudible unless the discrimination setting is 0.
AUTOMATIC GROUND CANCELLATION (FASTGRAB tm)
1 Find a spot of ground where there is no metal present.
2. Hold the detector with the searchcoil about one foot above the ground.
3. Push the TRIGGER SWITCH forward with your index finger
4. Physically "pump" the searchcoil and detector up and down over the ground.
Lift it about 6 inches above the ground and lower it to within 1 inch of the
ground, about once or twice a second.
5. A 2-digit value will appear on the display. This is the ground phase setting.
If the detector's internal computer is unable to cancel the ground signal, the
message CAN'T GC will appear; find another spot of ground and try again.
MANUAL GROUND CANCELLATION
In most situations, it is preferable to push the trigger switch to activate FASTGRAB
automatic ground cancellation. Generally, it is best to first let the computer automatically
cancel interference from ground minerals. However, for gold prospecting, searching on a
wet saltwater beach, or searching in an area with so much metal trash that there is no
"clean" ground for the computer to sample, we recommended that you cancel ground
manually. Manual ground cancellation requires a bit of skill, acquired with some practice.
The range of ground cancellation settings indicated on the display range from 0 to 99;
however, each displayed number spans 5 detent steps on the settings knob. The actual
internal ground cancellation setting changes with each step; there are a total of 500
different settings. Under some ground conditions you may be able to hear the individual
steps in the setting.
The Fe3O4 bar graph on the LCD display represents the amount of magnetic mineralization.
GROUND CANCELLATION (continued)
MANUAL GROUND CANCELLATION (continued)
The two-digit G.C. Phase number displayed on the LCD represents the type of ground
mineralization.
Some typical ground mineralization types are:
0 — 10 Wet salt and alkali
5 — 25 Metallic iron
26-39 Very few soils in this range -- occasionally some saltwater beaches
40-75 Red, yellow, and brown iron-bearing clay minerals
75-95 Magnetite and other black iron minerals
When manually ground canceling, try to 'feel out" a spot on the ground to make sure there
is no metal present. In order to avoid locking onto metal, the computer will not cancel
ground where the numbers are less than 30. Where the ground reads less than 30, manual
ground cancellation is required.
To perform the Manual Ground Cancellation operation, do the following:
1. Select the MANUAL G.C. function
The legend G.C. PHASE pops up.
The present ground cancellation setting is displayed (0-99).
The message area on the display will say PUMP COIL TO GC.
2. Physically "pump" the searchcoil and detector up and down over the ground.
Lift it about 6 inches above the ground and lower it to within 1 inch
of the ground, about once or twice a second.
3. Turn the SETTINGS KNOB to adjust the level.
The goal is to eliminate the sound as the coil is being pumped over the
ground. In some soils, the sound is not completely eliminated; rather, the
audio feedback is the same both when lowering the searchcoil to the ground,
and when lifting the searchcoil off of the ground.
If the ground cancellation adjustment is incorrect, there will be a difference in the sound as
the searchcoil is either moving toward or away from the ground. It sounds like you are
either pulling fhe sound ouf of fhe ground, or pushing fhe sound info fhe ground.
- If the sound is louder as you lower the searchcoil, reduce the
ground cancellation setting.
- If the sound is louder as you raise the searchcoil, increase the ground
cancellation setting.
NOTE: Experienced users often prefer to adjust the ground cancellation to
get a weak but audible response when lowering the searchcoil. This is
called "adjusting for positive response."
10
ALL METAL MODE
The All Metal mode is more sensitive and offers better "feel" than the Discrimination
mode, and is used to find all metal objects present in the ground. The searchcoil must be in
motion for the object to be detected. This is a "single filter" search mode similar to the
"fast autotune", "SAT", or "P4" mode found in other detectors you might already be
familiar with.
SENSITIVITY This controls the "electronic gain", and is adjustable from 1 to 99. In the
presence of electrical interference, high ground mineralization, or variable ground
mineralization, operation will usually be too noisy (wobbly and erratic sound from the
speaker) if the sensitivity is set too high. At settings above 90, the internal noise of the
machine will be clearly audible. The sensitivity level setting is largely a matter of personal
preference. However, if you cannot hear at least some noise, the smallest or deepest objects
will not be detected.
HUM LEVEL This is the same thing that some manufacturers call "audio threshold". It
is adjustable from -9 to +9. For maximum ability to hear the weakest signals, adjust the
background hum level high enough so that it is barely audible while the detector is in use in
the field. To eliminate the weakest signals, adjust the hum level into the negative region,
which will allow the machine to run silently if the Sensitivity is not set too high.
The hum level changes slightly with each detent step on the settings knob. Each number on
the hum level numeric readout corresponds to five steps.
MANUAL GROUND CANCELLATION
Manual Ground Cancellation can only be performed while in the All Metal mode, but the
resultant setting will carry over if you change into Discrimination mode. See the previous
section on Ground Cancellation for instructions on how to use this feature.
11
DISCRIMINATION MODE
The Discrimination Mode is used to eliminate from detection trash metal objects such as
nails, aluminum foil, or pull-tabs. The searchcoil must be in motion for metal objects to be
detected. Using discrimination incurs some loss of sensitivity to small or deep objects of
the desired types.
SENSITIVITY
This controls the "electronic gain", and is adjustable from 1 to 99. Unlike the All Metal
mode, the Discrimination mode is designed to operate silently. If you hear noise when there
is no metal present or when the searchcoil is not in motion, reduce the Sensitivity setting
until the machine goes quiet. NOTE: there is no interaction between the sensitivity
settings of the All Metal and Discrimination Modes.
DISCRIMINATION LEVEL
This is adjustable from 0 to 80, and controls the range of objects to be silenced
("discriminated out" or "rejected"). All objects with numeric values below the
discrimination level selected will not be detected. NOTE: the numerical range that pertains
to each class of objects is printed at the top of the visual display. To eliminate iron, a
setting of 40 is usually about right. A setting of 80 will eliminate aluminum trash and zinc
pennies, but nickels will also be lost.
NUMBER OF TONES
The T2 offers several selections of discrimination audio tones, described below. The
continuous (not sampled) selections will tend to be noisy with a lot of clicking and popping
in trashy areas, but offer better "feel" especially in plowed ground and rocky alluvium
where the ground is "lumpy". The sampled selections offer greater smoothness but poorer
"feel", and usually provide better performance over level ground that has few rocks in it.
1 Single medium pitch tone. Discrimination is continuous, not sampled.
1+ Same as 1, except that the audio pitch rises on strong signals. Large shallow
metal objects will give a squeal. The variable-pitch feature gives you more
information about the detected object, but some people find the sound on strong
signals too annoying.
2+ Generally similar to 1+, except that iron gives a low pitch tone regardless of
how strong its signal. The discriminator is continuous; however the part that
determines the iron tone is a partly continuous sampled system for greater accuracy
in "non-lumpy" ground.
3. This is a sampled tone discriminator with continuous discrimination
enhancement for better response. Iron gives a low pitch tone, aluminum trash and
zinc pennies give a medium tone, and most other coins including nickels give a
high tone. There may be some breakup in the tone on deep objects or if there are
multiple objects close together. If you're searching for coins in a trashy area, this is
usually the preferred mode __ you set the discrimination level to about 55 (below
nickels), and then you dig only the objects that give a high tone.
12
LCD VISUAL DISPLAY
In normal operation, when the searcheoil passes over a metal object, the electrical signature
("2-digit I.D.") of the metal object is displayed on the numeric display for 4 seconds, unless
superceded by another object sooner. On a given buried object, the number will bounce
around a lot if the signal is weak or if the amount of ground mineralization is high.
At the top of the display, an arrow indicates the class of object present.
NUMERIC TARGET l.D. (2-digits)
The following table shows the numbers typically associated with certain commonly
encountered nonferrous metal objects. Older silver U.S. coins usually read about the same
as their modern clad equivalents. Modern quarter-sized dollar coins like the Susan B.
Anthony and the Sacagawea read about the same as a quarter. Many Canadian coins are
minted from a magnetic nickel alloy which gives very inconsistent readings and may
register as iron. Most one-ounce silver bullion coins will fall into the same range as the
modern U.S. $1 Eagle.
OBJECT TARGET I.D.
foil from gum wrapper 40 - 55
U.S. nickel (50 coin) typically 89
aluminum pull-tab 60 - 75
aluminum screwcap 70 - 80
zinc penny (dated after 1982) typically 78
aluminum soda pop can 75 - 85
copper penny, clad dime typically 83
quarter 25c coin, clad typically 89
50 coin, modern clad typically 92
old silver dollar coin typically 94
US silver Eagle $1 coin typically 95
13
PROBABLE TARGET I.D.
The probable target 1D zones (classes) at the top of the LCD display represent the signal
ranges produced by various coin and metal object types. When a metal target is detected,
the microcomputer analyzes the signal and categorizes it based on what kinds of metal
objects usually produce that kind of signal. The microprocessor then lights up an arrow
along the top of the LCD screen above the icon which represents that category.
For instance, if the detected signal fits within the parameters usually exhibited by zinc
pennies and the electrically similar aluminum screwcaps, the microcomputer will
categorize the signal as "zinc penny - aluminum screwcap". The LCD screen will then
"light up" the arrow above the zinc/screwcap icon.
Copper pennies (pre-1982) will usually register in the 100 zone.
Most gold jewelry is small, and will tend to read in the 40-60 range. Silver jewelry usually
has more metal in it and therefore tends to give higher readings.
Since different metal objects can produce similar signals, and since minerals in the soil can
distort the signals, the probable target ID's are just that-- probable. There is no way of
knowing for sure what's down there other than to dig the target up and see. Experienced
metal detector users have a rule of thumb-- "when in doubt, dig".
TARGET DEPTH
When the trigger is pulled to facilitate pinpointing an object, the numerical display
indicates the approximate depth of the object, in inches, based on the assumption that it's a
typical US coin. Small objects will read deeper than they actually are, and large objects
will usually read shallower than they actually are.
G.C. PHASE
This is the ground cancellation setting, 0-99. It is displayed when in the Manual G.C.
menu setting, and when the trigger is pushed to do computer-assisted ground cancellation.
SETTING
This "lights up" when you are in the menu. When the word "SETTING" is indicated, the
number being displayed is a setting, and not, for instance, a Target ID indication.
MESSAGES
If a metal object or highly magnetic soil is so close to the searchcoil that the signal is
overloading the circuit, the message OVERLOAD - RAISE COIL will appear.
(Such overloads will not harm the detector, but the detector will not detect metals properly
signal under these conditions.)
Push the trigger forward to ground cancel; the message PUMP COIL TO GC will appear.
If after several seconds the detector is unable to acquire a ground measurement suitable for
ground canceling, the message CAN'T GC will appear.
14
BAR GRAPHS
Fe3O4 (magnetite) This bar graph displays the magnetic mineralization factor ("magnetic
susceptibility") of the soil, expressed in terms of the percent volume of the iron mineral
magnetite, which most "black sand" is made of. The depth to which objects can be
accurately identified is strongly influenced by the magnetic mineralization of the soil.
Detection depth in All Metals mode is less affected. NOTE: In order to get the most
accurate reading, "pump" the searchcoil once or twice as though you were ground
canceling. Otherwise the readings may be too low.
Fe3O4 approx.
Range micro-cgs description
3 7,500 uncommon but not rare, heavy mineralization
1 2,500 heavy mineral, not uncommon in goldfields
.3 750 heavy mineralization, but common
.1 250 medium mineralization, typical
.03 75 light mineralization, but common
.01 25 light mineralization, often low G.C. setting
blank <14 quartz & coral white beach sands
BATTERY CONDITION INDICATOR
Fresh alkaline batteries will indicate all four bars. When no bars are displayed and the
batteries are about to go dead, the BATT legend will start flashing. NOTE: If using NiMH
rechargeable batteries, the display will remain stuck on the second or third bar for most of
the battery life, and when it drops to the first bar, the batteries will go dead within several
minutes.
15
CAPABILITIES AND LIMITATIONS
DEPTH
The T2 can detect U.S. coins to a depth of about 12-15 inches under good conditions. Large
objects (55 gallon drums, manhole covers, etc.) can be detected to a depth of several feet.
Electrical interference from power lines and from electrical appliances and electronic
equipment can reduce detection depth, or cause audible interference making it necessary
for the user to reduce the sensitivity setting. Soils with large amounts of iron or salt
minerals may also reduce detection depth or necessitate a reduction in the sensitivity
setting.
TARGET IDENTIFICATION
The T2 identifies the probable type of metal object ("target") by measuring its effective
electrical conductivity, which is displayed as a number from 0 to 99 on the LCD screen.
The "effective electrical conductivity" of an object depends on its metallic composition,
size, shape, and orientation relative to the searchcoil. Since coins are minted to tightly
controlled specifications, they can be identified with good accuracy. Identification of pull-
tabs and foil is less consistent because these kinds of targets come in wide variety. In
general, smaller objects, and objects made from lower conductivity alloys such as iron,
bronze, brass, lead, pewter, zinc, will read lower on the effective conductivity scale.
Larger objects and objects made from higher conductivity alloys such as silver, copper, and
aluminum, will tend to read higher. The notable exceptions are gold, which usually reads
low because it's rarely found in large pieces; and zinc pennies, which read moderately high
because of their size and shape. Although nails and other iron and steel objects will usually
give low readings, ring-shaped pieces of iron (for instance steel washers and harness rings)
will usually give medium to high readings. Flat pieces of iron or steel, such as can lids,
will occasionally do the same.
Most targets can be identified accurately in air out to about 10 inches. The minerals in
many soils will cause identification to be less accurate. In most soils, effective target
identification can be had to a depth of at least 8 inches.
REQUIREMENT FOR MOTION; PINPOINT FEATURE
As with other modern metal detectors, the T2's searchcoil must be kept in motion in order
to both detect and identify targets. The All Metal mode is more forgiving of sweep speed
variation than is the Discrimination mode.
The trigger-activated Pinpoint feature continues to detect metal if searchcoil motion stops
over the target. The Pinpoint feature is used primarily to pinpoint the exact location of a
target so that it can be retrieved with a minimum of digging, and does not provide target
identification.
16
GROUND CANCELING
To achieve maximum depth in both the All Metal and Discrimination modes, as well as
when using the Pinpoint feature, the T2 offers the ability to cancel ground minerals either
by manual adjustment, or automatically using the FASTGRAB feature (see p.9).
If you do not perform the ground canceling operation, the Discrimination mode will usually
still work fairly well, but the All Metal mode will not. The Pinpoint feature can be used for
pinpointing objects at moderate depth in most soils without prior ground-canceling.
The internal computer will not cancel salt water, so when detecting in wet ocean beaches,
ground cancellation must be done manually.
DISCRIMINATION
"Discrimination" refers to a metal detector's ability to ignore (reject) metal objects in
selected categories, especially iron and aluminum. This makes searching an area where
there's a lot of metal trash much more pleasant. The T2 offers a wide variety of
discrimination features which you can select according to conditions and your personal
preference.
DEPTH READING
The estimated "Depth Reading" when using the Pinpoint feature is based on the strength of
the signal. It is calibrated for typical coin-size objects. Small objects will read deeper than
they actually are, and large objects will read shallower than they actually are.
AIR TESTING
There may be times when you want to test or demonstrate the metal detector without
sweeping it over the ground, for instance if it's not fully assembled, or if you're indoors.
Place the searchcoil in a spot where it's stable and more than two feet away from any large
masses of metal, including the reinforcing steel which is usually present in concrete. If
you're wearing a wristwatch or jewelry on your hand or arm, remove it. Then, test or
demonstrate by waving metal objects ("targets") briskly several inches over top of and
parallel to searchcoil.
Ground cancellation cannot be tested or demonstrated in air unless you happen to have
appropriate specimens of iron minerals or electronic ferrite available.
17
SEARCH TECHNIQUES
Sweeping Searchcoil (this does not apply to Pinpointing with the trigger switch)
Keep the searchcoil in motion to detect targets. Sweep the searchcoil parallel to the
ground; do not lift the searchcoil at the end of the sweep.
Pinpointing With Trigger Switch
When you turn the T2 on, the ground cancellation setting is preset to give a positive
response on all soils. This means that if you are pulling the pinpoint trigger, the audio tone
will get louder as you lower the searchcoil to the ground. But you don't want to hear the
ground; you just want to hear the target.
After you have discovered a buried metal target using the All Metal or Discrimination
Modes, use the trigger switch to pinpoint its exact location.
Position the searchcoil just barely off the ground, and to the side of the target. Then pull
the trigger, and raise the searchcoil about 2 inches. Lifting the searchcoil away from the
ground makes the ground signal go negative, so the machine is silent. Now move the
searchcoil slowly across the target, and you can tell where it is by the sound. When
moving searchcoil from side to side over a small object, move only a very small amount,
less than one inch.
Narrow It Down
To narrow the response, position the searchcoil near the center of the response
pattern, release the trigger, and then pull it again. Now you should hear a response
only right over the top of the target.
Because you aren't ground cancelled, this method will tend to make the deeper
targets vanish. However, in most soils this method will work for coins less than
about 7 inches deep.
----IF YOU GROUND CANCELLED (for advanced users)
Position the searchcoil about an inch off the ground, and to the side of the target. Pull the
trigger switch, and then move the searchcoil slowly across the target. You can tell where it
is by the sound.
To narrow the response, release the trigger, position the searchcoil near the center of the
response pattern, and pull the trigger again and hold it. Now you should hear a response
only right over the top of the target.
18
SEARCH TECHNIQUES (continued)
Estimating Target SIZE, DEPTH, and SHAPE
When the trigger is pulled to activate Pinpoint, the K2 LCD displays estimated depth. The
estimate is based on the presumption that it's a coin-sized target. But what if it's not a coin
sized target?
The most common example is that of an aluminum can. It will usually be identified as a
zinc penny or a dime. And, its large size will give a strong signal, tricking the
microcomputer into thinking it's a shallow coin. Here's how to tell the difference.
With the searchcoil close to the ground, sweep back and forth to get a feel for the target
response.
Now, continue to sweep back and forth as you slowly raise the searchcoil higher and
higher. If the response diminishes quickly and never gets very broad, the target is probably
a coin. If the response diminishes slowly as you raise the searchcoil, and you get a broad
response, the target is probably an aluminum can. If you practice this by laying a coin and
an aluminum can on the ground, after you've done it several times you'll know the
difference, and you'll probably never have to dig another aluminum can again. And, you'll
know whether it was deep or shallow. (This technique also works in the All Metal mode,
and to a lesser extent in Discrimination mode.)
Objects which are ring-shaped, or flat and round like coins, tend to give a narrower, crisper
response than an object of similar size but bulkier shape. The easiest way to demonstrate
this is with an aluminum screwcap from a soda pop bottle. In its normal shape, it occupies
a volume, and gives a somewhat broader response than that of a coin. But if you flatten it,
the response will be crisper and more like that of a coin. Again, these differences are most
readily noticed in All Metals operation.
Long skinny iron or steel objects such as nails usually give a double response when
scanned lengthwise, and a weaker single response when scanned crossways. This is most
noticeable in the All Metal mode. However, a coin on edge can give a similar response, so
rely on both target ID data as well as "target feel" to distinguish between different kinds of
objects. Objects within 2-3 inches of the searchcoil will often give multiple responses as
you sweep across them, because up close to the searchcoil the response field is irregular.
False Signals and Chatter
At times the detector may "beep" when there's nothing there, or at least it seems like
there's nothing there. There are four major causes for this: electrical interference,
nuisance buried objects, ground minerals, and "hot rocks". The problem can usually be
corrected by reducing the sensitivity setting, but sometimes other measures can also be
taken.
ELECTRICAL INTERFERENCE
Electrical Interference can be caused by power lines, appliances, fluorescent and vapor type
lamps, household light dimmers, other nearby metal detectors, electric fences, radio
transmitters, and electrical storms. If you get abnormal noise even while holding the
searchcoil motionless in the air, the cause is electrical interference. By walking around
with the metal detector, you can often "follow the signal" and track it back to the
19
SEARCH TECHNIQUES (continued)
False Signals and Chatter (continued)
Electrically conductive natural minerals such as graphite, graphitic slate, or sulfide ore
minerals are rarely encountered except when gold prospecting. When gold prospecting,
you need to be able to hear everything, and you can expect to dig conductive minerals that
turn out not to be gold. In a given locality you may learn to recognize what type of rocks
these minerals are found in, and to ignore them if people in the area say that gold isn't
found in rocks of that type.
HOT ROCKS
A "hot rock" is a rock which causes the metal detector to "sound off' because of its iron
minerals. They come in two basic types.
"Negative hot rocks" (also called "cold rocks") are usually magnetite or contain
magnetite, and give a negative response because their ground cancellation phase is a
higher number than the soil they are found in. They tend to be dark in color,
usually black, and usually heavy. In some cases they will have rust stains. They are
usually attracted to a magnet, and for this reason gold prospectors always carry a
magnet ______ the ultimate ferrous/nonferrous "discriminator". In All Metal mode,
negative hot rocks give a "boing" sound rather than the "zip" sound of a metallic
target, so it's frequently possible to recognize the sound and then to ignore them.
"Positive hot rocks" are iron-bearing rocks which have been oxidized by natural
weathering processes so that their ground cancellation phase is a number lower than
the soil they are found in. They are often small, right on the surface, sound just like
a gold nugget, and are common in many gold prospecting areas. They are usually,
but not always, drawn to a magnet. They are most often reddish in color but are
often black, brown, or yellow. On relic hunting sites, red clay bricks and rocks
which have lined a fireplace or a campfire will often be "hot rocks". The
discriminator will usually eliminate them without difficulty if widely scattered, but
if there is a large concentration of them the discriminator may not quiet them all. In
that case, you can revert to the rule of thumb "don't dig nonrepeatable signals".
Using the sensitivity control
When the T2 is first turned on, the Sensitivity is at a medium setting appropriate for most
"coinshooting". For relic hunting or gold prospecting higher Sensitivity settings are
preferred.
If the event of nuisance detection signals due to electrical interference from electrical
power lines, electrical or electronic appliances, or another metal detector, it is usually
necessary to reduce the Sensitivity setting to achieve quiet operation.
If while searching you are constantly getting signals from which you can't recover metal
targets, you may be detecting small or deep targets which aren't recoverable using the
methods at hand. So, you may do better if you reduce the Sensitivity setting.
21
Tips on ground canceling
When the T2 first turns on, the ground cancellation is preset to 90. This will give a
"positive" response on most soils. If you search in the Discrimination mode, you probably
won't have to cancel the ground. If you switch to All Metal mode, ground cancellation will
probably be necessary.
To properly set the ground cancellation, a spot of ground with no metal is necessary.
Before you attempt to ground cancel, sweep back and forth to see if it seems like a metal
target is present. If so, first locate what seems to be a clear area and then ground cancel.
Ground cancellation may be done automatically by pushing the trigger, or manually if you
are in All Metal mode. After you have ground cancelled, sweep back and forth to see if
there is little or no response to the soil. (This is best done either in All Metal mode, or in
Discrimination mode with discrimination set to zero. It can also be done by pulling the
trigger to activate Pinpoint.) If there is little or no response, ground cancellation was
successful. If there is still substantial response, there may have been metal present where
you attempted to ground cancel, so find another promising spot and try again. If you can't
find a spot to successfully ground cancel, it's time to give up. Turn the machine off, turn it
on again so the ground balance preset will be restored, and then use the machine without
ground canceling.
In most areas, once you've ground cancelled, the ground cancellation setting will remain
satisfactory for a long time. However, if the soil has been disturbed by digging or bringing
in fill dirt, or if you are in a geologically complex setting such as is commonly encountered
in gold prospecting areas, you may have to frequently perform the ground cancellation
procedure to accommodate changing soil conditions.
When you ground cancel, the numerical value of the ground balance setting will
momentarily appear on the LCD screen. In general, sandy or gravelly soils will tend to
read in the 75-95 range, light colored barns and clays will tend to read in the 50-80 range,
and red clays will tend to read in the 35-55 range. To express it in other terms, in general
the more highly weathered and oxidized the soil is, the lower the numeric reading will be.
The Fe3O4 bar graph indicates how much iron mineralization is present. For it to work, the
searchcoil has to be maintained in motion. The most accurate readings will be achieved by
"pumping" the coil as you do when ground canceling. The greater the mineralization, the
more necessary it is to be ground cancelled in order to get the best depth performance.
If you are searching for relics, you can make a map of the soil of the site. Make a grid of
the site. Then take data on the mineral type by ground canceling, and on mineral amount
by looking at the Fe3O4 bar graph. Then plot the data on the site map and draw isolines. In
this way you may be able to locate areas which have been dug, backfilled, or subjected to
fire. This information in turn helps to reveal the history of the site.
22
Detecting Activities
Coinshooting
Coinshooting means searching for coins, usually in places like parks, schoolyards, church
lawns, and people's residential yards. In most places where coins are likely to be found,
there's a lot of aluminum trash like pull-tabs and bottle caps, as well as steel bottle caps and
often nails. Sometimes there's jewelry. You'll usually search using discrimination to get
rid of the iron and the aluminum trash, even though that'll cause you to miss some of the
jewelry.
Much coinshooting is done in lawn areas, where digging holes would cause damage to the
grass. Recovering targets is usually done by carefully cutting a slit in the turf with a knife,
and tamping it firmly when you're finished. In these situations you can't recover deep
targets, so you can cut down on nuisance signals by reducing the sensitivity.
When searching on private property, first get the permission of the property owner. Most
of the public places where one would be likely to do coinshooting are city, county, or
school district property. Usually there's no ordinance prohibiting use of a metal detector as
long as you're not causing damage. However, sometimes such ordinances do exist, and
administrators and security personnel often have the legal authority to prohibit any activity
they don't like even if there's no ordinance against it. If there is a metal detecting club in
your area, someone will usually know what areas can and can't be "beeped".
It's always a good idea to be ready to put your best foot forward when using a metal
detector in a public place. Any trash you see or inadvertently recover, pick it up and put it
in a pouch or pocketed apron. This way you can explain that you are performing a public
service by helping keep the place free of trash, especially pieces of metal or glass that could
endanger a child at play. Be proficient at recovering targets without causing damage to the
lawn. Explain that whenever you find jewelry which has personal identifying marks such
as a class ring, you make an attempt to determine the owner and to return it. When
someone who questions what you're doing finds out that you are causing no damage and
are actually performing a public service, usually from then on out you'll be welcome.
Relic Hunting
"Relic hunting" is searching for historical artifacts. The most common desired objects are
battlefield debris, coins, jewelry, harness hardware, metal buttons, trade tokens, metal toys,
household items, and tools used by workmen and trades people. The most common
unwanted metal is iron (nails, fence wire, rusted cans, etc.), but some iron and steel objects
such as weapons may also be valuable. If you're on a site where you may encounter
unexploded ordinance, use caution.
Most relic hunting locations are in fields, forested areas and vacant lots where digging
holes won't damage turf grass, so having a detector with good depth sensitivity is
important. Some places are so littered with iron that it's necessary to discriminate out iron
in order to be able to search, even though you will miss some potentially valuable artifacts
that way.
23
Relic Hunting (continued)
Before you go relic hunting, obtain permission from the property owner. If you intend to
hunt on public land, check first with the administrator to make sure it's not illegal. Certain
kinds of sites on both public and private land are protected by law from relic hunting. If
there is a metal detecting club in your area, some of the members will probably know what
the laws are in that area and which sites are and aren't off limits.
Relic hunting is most rewarding if you have an avid interest in history. In many cases, the
value of a relic is not the object itself, but the story it's a part of-- what historians call
"context" and archeologists call "provenance". A few pieces of rusty metal that tell a story
of life in a specific place or even of a specific family or person hundreds of years ago, can
capture our imagination and help to give context to our own lives now. But if those pieces
of metal are mixed in with other similar stuff and their context lost, they become trash. So
take the trouble to understand the site you're searching and keep track of where you found
things.
The ground cancellation and Fe3O4 bar graph features of the 2 can be used to map the soils
on a site. In this way you may be able to determine which areas have been dug, backfilled,
or subjected to fire. This information in turn helps to reveal the history of the site.
To find promising sites to hunt, do some research in your local library, look for clues in old
newspapers, and see what information you may be able to find on the Internet. Where did
buildings used to be, which have since been torn down? Where did people gather for
public events like dances and county fairs? Where did train and stage lines run? Where
were the swimming holes? In almost every town there is a historical society and museum
of local history. Most museums are grateful for anything they can put on display, and
when you dig something you can't identify, the curator can often identify it for you. If you
work closely with the historical society and the museum, landowners will be more willing
to give permission for you to search on their property.
Some of the most promising sites for relic hunting are places which are being cleared for
development. After the site is built on, whatever is there in the ground will be inaccessible.
The property owner can often be persuaded that the site should be searched immediately
while it is still searchable.
Gold Prospecting
Gold is found in many places throughout the Western States, Alaska, and in a few localities
in the Appalachians. The old saying "Gold is where you find it", means that to find gold,
you should look in areas where the yellow metal is known to be present.
The best areas for gold prospecting using a metal detector are usually hillsides, because
hillsides can't be "cleaned out" by panning and dredging the way streams can. Also, gold
on hillsides not far from its source vein tends to be larger (and hence more readily detected)
than alluvial (placer) gold which tends to get pounded to pieces and worn away as it rolls
along the streambed with the gravel during floods. Gold is valuable because there's not
much of it. Even in a good gold producing area, you'll often spend an entire day without
24
Detecting Activities (continued)
Gold Prospecting (continued)
finding any gold. Meanwhile you'll be digging bits and pieces of other metal-- birdshot,
shells and bullets from hunting and target practice, bits of rusted barbed wire, chips off
shovels and other mining tools, rusted tin cans, etc. "Hot rocks"-- rocks containing
concentrations of iron oxides that sound like metal when you pass over them-- are also a
nuisance in many gold areas. Discrimination is usually ineffective because the loss of
sensitivity resulting from discrimination is enough to cause those little nuggets to vanish.
If you've gone many hours without finding gold and are wondering if maybe there's
something wrong with your metal detector or the way you're using it, the most important
clue is this: if you're digging tiny pieces of trash metal, if you'd swung your searchcoil
over a gold nugget, you'd have dug that too.
Because most gold nuggets are tiny, and are usually found in soil which is high in iron
oxide minerals, serious gold prospecting requires a detector with high sensitivity and true
ground cancelled motion all metal operation. Run the machine with the sensitivity high
enough to hear some noise from ground minerals, and "learn the language" of the sounds
you hear. Headphones are recommended unless consideration for safety (for instance
rattlesnakes) rules them out. Move the searchcoil slowly and deliberately, carefully
controlling its height above the ground to minimize noise from the iron minerals in the soil.
Perform the ground cancellation procedure again whenever you suspect the ground
cancellation may be a bit off.
The Fe3O4 bar graph indicates the amount of iron mineralization in the soil. In most gold
areas, especially alluvial (placer) deposits, gold tends to be associated with iron minerals,
especially magnetite "black sand". If you know this to be the case in the area you're
working, you can maximize your gold recovery by concentrating your effort on areas
where the bar graph indicates higher amounts of iron mineralization.
Gold prospectors are mostly a friendly bunch, and willing to spend some time showing a
beginner how to increase your odds of finding the yellow stuff. Many will invite you to
search on their claims (if they have any) once they get to know you. In some gold areas, a
lot of the terrain is under claim, so you need to learn how to recognize posted claims and
stay off of them unless you have the claim owner's permission to be there. Prospecting
clubs such as the GPAA often own claims which are open to their members, and sponsor
group outings to good gold areas.
To dig into the ground and pull out a precious piece of yellow metal that you are the first
person on earth to see, can be a thrilling experience. If you love being outdoors, have
patience, and can stay motivated by the prospect of finding that next nugget, then "beeping
for gold" may be the hobby for you. Not many people get rich by gold prospecting, so the
most important thing is to think of it as outdoor recreation that may pay some of the
expenses, and to have fun doing it.
25
Detecting Activities (continued)Cache Hunting
Cache Hunting
A "cache" (pronounced "cash") is an accumulation of money, jewelry, gold, or other
valuables, which someone has hidden. When people bury a cache, they usually put it in a
strongbox or in a jar. To search for a cache, first you need a reason to believe the cache
may exist. This means doing research. Some caches have been the subject of many stories
you can read about in print, but you need to be able to sort fact from fiction. If you can get
copies of old newspaper stories about the circumstances surrounding the hiding of the
cache, you may find discrepancies which help you to judge the reliability of the
information available. Often the best information on an old cache is to be learned from old
timers who live in the area where the cache is thought to be. In the case of newer caches,
often the only information is what can be obtained from family and acquaintances of the
person who is believed to have hidden the cache.
The ownership of a cache is not always clear. Sometimes it belongs to the person or heirs
of the person who hid it, sometimes it belongs to the owner of the property on which it is
located, and sometimes it belongs to the person who finds it -- or some combination of the
above. If the contents of the cache was stolen to begin with, that fact can also complicate
the question of ownership. Find out what laws apply to the cache in question, and always
make sure that the issue of ownership is resolved prior to recovering a cache.
Compared to a coin, a cache is usually large and deep. You'll probably want to search in
All Metal mode. However, for a really deep cache, it may be advantageous to search in
Pinpoint, frequently releasing the trigger momentarily to cancel drift.
Shallow Water Hunting
All First Texas Products searchcoils are waterproof, allowing you to search in shallow
water up to a foot or so deep. However, if you're searching around water, be careful not to
get the electronics housing wet. Avoid salt spray, as it will work its way into the control
housing and damage the electronics-- such damage is not covered under warranty.
Both fresh and salt water beaches are popular places for metal detecting. Vacationers lose
money and jewelry playing in the sand and in the water. It's usually easy to dig in a beach
environment, and metal detecting is permitted on most beaches. Once in a while you may
be able to recover for someone a piece of jewelry they've lost minutes before, which is a
gratifying experience.
When searching on a beach, it's best to either search in All Metal mode, or to search with
the discrimination level set just high enough eliminate iron, because the value of beach
finds is largely in the jewelry rather than in the coins. You'll dig a lot of aluminum trash,
but the digging is easy, and you can tell people that you're helping to clean up the beach
and make it safer for people's feet. You may want to use a special "sand scoop" for
recovering valuables from the sand quickly-- most metal detector dealers sell these.
The electrical conductivity of the water itself can pose some challenges. You may get false
signals when going into and coming out of the water, making it necessary to pay careful
attention to keep the coil either in or out of the water but not to touch the surface. This
effect may be observed in either fresh or salt water.
Detecting Activities (continued)
26
Shallow Water Hunting (continued)
Salt water is highly conductive, and produces a strong signal which is like that of metal.
When searching in salt water, the following measures will usually be sufficient to silence
the salt water response while retaining acceptable sensitivity:
1. Set the sensitivity in both modes to 30 or less.
2. Ground cancel the machine manually in All Metal mode.
3. Search in the Discrimination mode with a discrimination setting
higher than 45, and "1+" tones.
HOW METAL DETECTORS WORK
Most hobby metal detectors for finding buried objects are of the "VLF Induction Balance"
type. Here's how they work.
The searchcoil (also called "search head" or "loop") on the end of the tube assembly
("stem") contains two electrical induction coils which are like antennas. One coil
transmits a rapidly alternating magnetic field, "illuminating" the region surrounding the
searchcoil. If metal is present, its electrical conductivity distorts the magnetic field. If iron
metal is present, its magnetism also distorts the magnetic field, but in a different way,
allowing the metal detector to distinguish between ferrous and nonferrous metals.
The other coil is a receiving antenna which detects changes in the magnetic field caused by
the presence of metal. The electronic circuits amplify this weak signal, analyze it to
determine what kind of change is occurring as the searchcoil is swept past the metal object,
and then convey the information to the user in the form of an audio tone and /or a visual
display of some type. Most advanced metal detectors perform some of these tasks in
software running on an internal microcomputer.
The iron minerals which are present in most soils also distort the magnetic field, often
obscuring the weak signals of small or deep objects. This can cause the object to go
undetected, or to be misidentified if it is detected. Much of the technology that goes into
modern metal detectors is devoted to the task of eliminating the unwanted signals from iron
minerals in the soil, while not losing the signals from metals.
5-YEAR LIMITED WARRANTY
The Teknetics T2 metal detector is warranted against defects in materials and workmanship
under normal use for five years from the date of purchase to the original owner. Liability
in all events is limited to the purchase price paid. Damage due to neglect, accidental
damage or misuse of this product is not covered under this warranty.
Liability under this Warranty is limited to replacing or repairing, at our option, any
Teknetics metal detector returned, shipping cost prepaid, to:
First Texas Products, L.P.
1100 Pendale Rd.
El Paso, TX 79907
27
~and~
