OPERATING TECHNIQUES 25
Recognizing false signals in Discriminate Mode
When operating in the Discriminate Mode, some "false signals" may be caused by 1)
heavy concentrations of trash metal objects, 2) very large trash metal objects, or 3)
electrical interference. These signals are generally short, choppy sounds and sound
different than "good signals" (good target response sounds).
At the end of your sweep, as you reverse the coil direction, the detector is most
susceptible to trash induced noise. There are two ways to tell whether these sounds are
good deep signals or trash "noise." The first is by repeatability. Trash induced noises will
not be regular as you sweep the coil over the suspected target several times, whereas a
good target response will be repeatable. The second method is to switch to Pinpoint
Mode and check the target response sound. If the response is weak, it may well be a deep,
good target. But if the response is very strong, it is probably trash. Note that a coin close
to the surface can give a double beep sound, but it is regular and repeatable. Raising the
coil an inch or two will restore the single beep on surface targets. When searching in the
Discriminate Mode, it is best not to use a higher DISC LEVEL setting than necessary.
Nickels and most smaller rings are rejected when the DISC LEVEL is set to reject pull
tabs on any metal detector that is a Trash Discriminator like the
SIIADOWX2. If you don't
dig any junk at all, you are surely passing up a lot of good finds as well. Set the DISC
LEVEL only high enough to suit the conditions where you are searching. If there is any
doubt whether a target is good or not, dig it.
Pinpointing a target
Pinpointing a target in Discriminate Mode is probably best done by "X-ing" as well.
Remember that the detector will beep just as the target passes under the center of the
searchcoil. Slowing the sweep speed down will help you pick out the center of the X
because the target response is reduced at very slow speeds making it easier to correlate
the sound with the coil center. Another easy method is to sweep the coil from side to side
across the target in very short sweeps as you slowly move forward and backward across
the target. Slow down the sweep rate and shorten the sweeps until you just barely get a
response at one spot. The target will be directly below the coil center at this response
time.