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TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
SEARCH TECHNIQUES (continued)
NUISANCE BURIED OBJECTS
In some areas there is a lot of metallic trash which produces weak signals. These could
include deeply buried objects, little bits and pieces of rusty iron and corroded foil. These items
can be detected, but are difficult to pinpoint due to their depth and small size. When you dig
and find nothing, it may seem like the machine is beeping at nothing even though there is
actually something there. The best solution is usually to reduce sensitivity.
If searching a very trashy area and unwanted signals are a problem, search with the
searchcoil 2 inches away from the ground. Trash objects very close to the searchcoil will
sometimes not be completely eliminated, even when the discrimination setting should have
eliminated the target.
Metal detectors are designed to see one metal object at a time. Where there are two iron
objects near each other, the detector can be fooled into thinking that the gap between them is
nonferrous metal. This is a common condition where a wooden building has burned or been
torn down, and the site is littered with nails. A signal from a nonferrous metal object such as a
coin will usually be repeatable, whereas a false positive signal resulting from multiple or oddly
shaped iron objects will seem to wander around and even to vanish. Experienced detectorists
call these non-repeating signals and usually do not bother digging them since nonrepeating
signals are almost always trash.
GROUND MINERALS
Conductive mineral salts usually produce broad signals which will not be mistaken for a
metallic object. Common causes are concentrations of mineral fertilizer, spots where
evaporation has concentrated naturally occurring mineral salts, residue from de-icing salts,
and urine from livestock. Unless dry, “cow pies” can sound off like they are metal. Ocean
beaches have salt water—that subject is discussed elsewhere in the manual.
In spots where there has been intense fire, such as a campfire site or where a stump was
burned during land clearing, the soil minerals may be altered by oxidation so that their ground
cancellation setting is lower than that of the surrounding soil. In such cases, search slowly and
change the G.C. setting as frequently as necessary.
In some areas, electrically conductive industrial minerals such as smelter coke, slag, and
charcoal have been dumped or used as landfill. Individual lumps of these materials can
usually be quieted by reducing sensitivity and searching with a discrimination level of at least
50. However, where the ground consists primarily of such materials, you may not be able to
search quietly. In that case, do not dig unless a signal is crisp and repeatable.
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 is not found in
rocks of that type.
SPECIFICATIONS
Mechanical: S-rod with electronics housing mounted on handgrip, 3-piece breakdown,
batteries under elbow, 2-way armrest adjustment — forward/backward & around forearm.
Searchcoil: 11” (28 cm) open-frame elliptical double-D, waterproof.
Batteries: 4 AA, alkaline or NiMH (not included).
Weight: 3.5 pounds (1.6 kg) with alkaline batteries installed.
Static Balance: force in vertical plane normal to elbow 0.47 pounds (0.22 kg).Varies with
adjustment and user’s stance and arm/hand physiology.
Dynamic Balance: axial moment, 0.29 foot-pounds (0.39 newton-meters). Varies with
adjustment and user’s stance and arm/hand physiology.
Sweep Effort: lateral moment 5.2 foot-pounds (7.1 newton-meters).
Operating Principle: VLF induction balance
Operating Frequency: nominal 13 kHz, quartz crystal timing reference
Basic Sensitivity: 5 x 109 root Hertz (detectivity)
Lag Coefficient: 70 milliseconds
Reactive Overload: approximately 10,000 micro-cgs units (volume susceptibility)
Resitive Overload: approximately 1,200 micro-cgs units (volume susceptibility)
Ground Cancellation Range: From ferrite to salt, inclusive
Discrimination Ground Suppression: combination of second and third order methods
ID Ground Suppression: third order
Battery Life: typically 40 hours with good quality alkaline, somewhat less with NiMH rechargeable.
Operating Temp Range: -4 to +122 degrees F (-20 to +50 degrees C)
Operating Humidity Range: 0-90% non-condensing
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