Notes:
. A good detection has a consistent rise and drop of threshold tone. A poor
detection has irregular highs and lows in threshold tones. lf the metal is in the
shape of a circle, like a watch or loop of wire, opposite reactions may occur.
. There are ways to tell whether threshold tones are good deep signals or trash.
A good target response repeats as you swing the searchcoil over the suspect-
ed target. Trash-induced signals tend to not repeat.
. Recently buried coins might not respond the same as coins buried for a long
period of time.
. Some nails, nuts, bolts, and other iron objects (such as old bottle caps) oxidize
and create a halo effect around these objects.
A halo effect is caused by a mixture of natural elements in the ground and the
oxidization created by different metals. Because of the metal mixtures, target
signals may not be in a "fixed" position. This effect makes these objects very
hard to reject. (See "Fine Tuning.")
18 19
FINE TUNING
Once you become familiar with how your metal detector works, you can fine-tune
it to be more selective in what it finds. You can make it tune out undesirable ob-
jects and tune in precious metals. For example, you can set it to distinguish
between iron and gold. With the D|SCRIMINATE and PULL TAB REJECT SETTTNG
controls, you can determine an even greater distinction between these metals.
Discriminate
DISCRIMINATE distinguishes between junk and
valuable metal objects, and automatically rejects
nails and most iron. To adjust D|SCRIM|NATE,
rotate SETTING to DISC. Then. rotate DISCRIM-
INATE from LOW to HlcH. As you rotate
DISCRIMINATE in a clockwise direction, the
detector progressively rejects other iron, foil,
nickels, pennies and dimes. The range from
LOW to HlcH changes the frequency of your
detector, which allows the detector to reject
these metals.
