User's Manual

24 17
TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
TEKNETICS
Comprehensive Operating Manual & Guide to Metal Detecting
CAPABILITIES AND LIMITATIONS (continued)
STEEL BOTTLE CAPS & FLAT IRON TRASH
Modern motion-type Target-ID metal detectors usually have difficulty consistently identifying
steel bottle caps and other flat iron trash objects. Double-D searchcoils also have a reputation
for being unable to distinguish steel bottle caps from coins, and for being unable to eliminate
steel bottle caps from detection. If you are searching in an area where there are many steel
bottle caps or other flat iron trash targets, minimize the amount of unnecessary digging with
the following methods:
1. Search with the 3b (bottle cap) method using the # OF TONES feature. This
method calculates visual ID differently in order to cause steel bottle caps to read lower
on the scale, and to register less consistently. A desirable object such as a coin will
usually produce numeric values that are fairly consistent in both directions of sweep.
See # OF TONES under the DISCRIMINATION Mode section of this manual.
2. Search in dP mode. This method calculates visual ID differently in order to cause
steel bottle caps to ID lower on the scale and to register less consistently. It also
produces more audio clues to the character of the target.
3. Lift the searchcoil or sweep at an angle. Within 2 inches of a Bi-Axial
searchcoil, the crossed magnetic fields of the Double-D construction can produce
anomalous responses. If the object feels shallow (strong signal, narrow response, or
multiple responses in a single sweep) and is giving consistent high readings like a
coin, raise the searchcoil 2 to 3 inches and try again. A coin will almost always
continue to give consistent readings unless it is right next to an iron object.
A steel
bottle cap that is at least 3 inches away from the searchcoil will
usually produce readings that bounce around from medium to
low numbers.
4. Sweep REAR of coil over the target or sweep fast
1. If the ID# is repeatable around 81 to 84, when passing over
center of searchcoil at normal speed, then target should be a
dime or copper penny.
2. If not in the range of 81 to 84, then:
a. Sweep the back end of searchcoil over the target. If
tones change from high to a low tone, it is probably a
bottle cap.
b. Sweep center of searchcoil fast
across target.
i. If tone and ID-value drop, it is
probably a bottle cap.
ii. If a bottle cap, the faster you
sweep, the lower the tone.
Sweep back end
of searchcoil over
suspected bottle cap.
(Low Tone = Bottle Cap)
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DISCRIMINATION MODE (continued)
The “# OF TONES” selections are (continued)
3b: Bottle Cap Mode Similar to 3, but modified so that
steel bottle caps will usually produce inconsistent, or
non-repeatable, tones and broken sounds. There
may be a slight reduction in the ability to separate
adjacent targets. Use this method in areas with a
high concentration of steel bottle caps. Also refer to
p. 25 for sweep techniques to aid in the identification
of steel bottle caps.
4: Four different audio tones This method is similar
to 3, but with a fourth medium-high tone for targets
in the numeric range of 73 to 79. This four-tone
system is useful for searching in areas where there
may be very old coins which register in this range.
dP: Delta Pitch This method produces a tone whose pitch varies in relation to the visual ID
number — the higher the ID, the higher the pitch. Good for relic hunting. Sampling is
mostly continuous. This method is also useful in areas with a high concentration of steel
bottle caps. Coins will produce a fairly constant pitch as you sweep back and forth. Bottle
caps produce inconsistent tones, often with a squawk at the beginning of the sound.
FA: Fast Process This is best for trashy areas with little EMI it gives sharper response to targets.
bP: Boost This selection is an enhanced sensitivity version of the 2+ # OF TONES
selection. It is particularly useful when searching for deep targets in a non-trashy area, or
on a site where vegetation makes it necessary to raise the searchcoil several inches
above the surface of the ground. It will also produce excellent results on trashy sites
provided that you slow down your sweep speed; sweep the coil slower than you would
when using 2+. When bP is selected, the response characteristics of the All Metal Mode
are also modified; these characteristics include less noise and a slower response speed.
CL: Cache Locating This selection is an enhanced sensitivity, slow-speed, version of the
2+ # OF TONES selection. Its primary use is in locating large deep objects while
sweeping the searchcoil several inches above the surface of the ground; under these
conditions it goes deeper than the other # OF TONES selections. When CL is selected,
the response characteristics of the All Metal Mode are also modified; these characteristics
include less noise and a slower response speed. In many situations, you may prefer to do
cache locating in the All Metal Mode after first selecting CL in the Discrimination Mode.
What You See vs. What You Hear
The visual Target-ID displayed on the LCD is based entirely on sampled processing; the
number displayed represents the snapshot. When using these different “# OF TONES”
methods, the detector’s audible response may differ from the visual. Using these methods,
there is not a 100% correspondence between what you see and what you hear, especially on
buried targets where ground minerals influence Target-ID and audible response. By making
the audio and visual systems independent, the T
2
allows each system to do what it does best.
The audio is optimized for quick response and target feel, whereas the visual system provides
the best numeric resolution of Target-ID.
Audio Pitch
This setting carries over into Discrimination V.C.O. Audio tone.