Fisher 1225-X manual False Signals

FALSE SIGNALS

A “false signal” occurs when something that shouldn’t, sounds like a good target. Your 1225-X does an excellent job of ignoring junk but it’s so sensitive to good targets that it can be fooled by bad targets with similar electrical characteristics. Large pieces of trash for example, or even some kind of bottle caps and pull tabs. Small pieces of trash less than 2 inches from the search coil will also sound good occasionally.

So what do you do about false signals? Well, 90% 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 disappear if the coil is speeded up or raised slightly. Some shallow, large or irregular pieces of junk however, will fool the 1225-X no matter what you do. Here’s some other sources of false signals and what to do about them:

1.DETECTOR INTERFERENCE: Caused by nearby metal detectors operating at the same (or close) frequency.

SOLUTIONS: Move further away or reduce sensitivity.

2.ELECTRICAL INTERFERENCE: Caused by Radio/TV stations, power lines, etc.

SOLUTION: Move further away, lower the sensitivity, reduce sweep speed. Wrap the search coil cable tightly around the stem.

3.HIGHLY MINERALIZED SOIL: Usually causes constant static or good target sounds. SOLUTIONS: Lower the sensitivity, increase the discrimination. Raise the search coil until false signals disappear and sweep at that height.

4.WET SAND: Same as highly mineralized soil.

5.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 coin on edge will give the same response. SOLUTIONS: In all cases, the target will be

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