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Due to the sensitivity of the 1212-X, you’re bound to get some
“false signals” once in awhile. A false signal occurs when
something that shouldn’t, sounds like a good target. The 1212-X
does a good job of rejecting junk but it can be fooled by “hot”
mineralized spots in the soil, large pieces of junk, some kinds of
bottle caps and pull tabs or trash less than 2 inches from the coil.
So what do you do about false signals? Well, 90 percent of
them will sound suspicious to you after you’ve had some
experience, and you’ll just ignore them. They may be very faint
or very abrupt with static. Often when you go back over the
same spot, a false signal will simply disappear. Other false signals
may be very loud and sharp, but most of these will also disappear
if the coil is speeded up or raised slightly. Some shallow, large or
irregular pieces of junk, however, will sound off no matter what
you do. You may reduce the number of false signals by increasing
the trash rejection level. Some other sources of false signals are:
1.
ELECTRICAL INTERFERENCE:
Caused by radio/TV
stations, power lines, or nearby detectors
operating at the same frequency.
SOLUTION:
Move further away, reduce sweep
speed.
2.
HIGHLY MINERALIZED SOIL:
Usually causes constant
static on good target sounds.
SOLUTION:
Increase
trash rejection level, raise the search coil until false
signals disappear and sweep at that height.
3.
WET SAND:
Same as highly mineralized soil.
4.
ELONGATED FERROUS OBJECTS:
If you hear two
beeps very close together and can’t find either
one, you’re probably over a nail or some other long
iron object. But a very shallow coin or a buried coin
on edge may give the same response.
SOLUTION:
In all cases, the target will be between the beeps
or, if you sweep at right angles to your original
direction, you’ll receive a single beep directly over
the target (except for the very shallow coin). One
way to tell the difference between a coin and a
nail is to set your trash rejection to about 5. Most
small nails will be tuned out while most coins will
respond with a good, smooth signal.
FALSE SIGNALS
