Metal Detectors For Hobbyists

Metal detecting is one of the fastest growing hobbies in the world. Why? It is the only hobby you get paid to do, if you learn the proper operation of your metal detector.

For metal detecting to be rewarding it is essential that you have a basic understanding of how a metal detector operates. All metal detectors have an invisible field around the coil or loop as it is sometimes called. When this field comes in contact with metal either underneath it in the ground (or in the water) or sometimes above it in the air, the detector gives a signal. This is a simple description of how a hand held metal detector works.

There are three general types of metal detectors in use in the hobby. The oldest type is the BFO (Beat Frequency Oscilator). Ther are simple to use but limited in their depth capabilities. The most common type is the VLF (Very Low Frequency) and they have many great features with the cost increasing in a direct relation to the bells and whistles that are added. These capabilities or features include: discrimination, Notch Discrimination, Target Identification, Target Tone ID, Target Signature, Multiple Signature, Multiple Frequency, Silent Search, Ground Balance, Depth Reading and several others including some computer visualization features. The third type is the PI (Pulse Induction). This type is generally not good at discriminating targets but work best in highly mineralized soil like gold fields and are excellent in salt water beach detecting. The PI and VLF (operating in all metal frequency) have far superior depth to the older BFO units. Depth is important but not the most important element to metal detecting success. I have dug more than 150,000 coins (and thousands of other treasures) and 80 percent of them have been less than 5-7 inches deep and even the older BFO units can go these depths in lightly mineralized soil. The single most important element to metal detecting success is knowledge.

All metal detectors have a loop or coil. Each coil type has its own special characteristics. The two most common types are the concentric and the double "D". Both of these are wide scan coils. This means that nearly the whole loop area will receive signals from metal objects that are not buried deep. This is easily seen by putting a penny or dime on top of the ground that is clear of other metal and move the coil back and forth over it at just and inch or two above the ground. Neraly every area of the coil will elicit a signal from the coin. Now raise the coil to about four or five inches above the coin and do the same movements again. This time not all areas of the coil will obtain a signal. The higher you raise the coil above the coin the smaller the area of the coil receives a signal. The field that is emitted from these standards coils is in essence cone shaped. The deeper a coin or other metal object is buried the greater the need to overlap the coil sweep.

It is very important that you understand your detector's coil features. The easiest way to do this is to do an air test with a coin. Keeping the coil in a horizontal position, turn the detector on and adjust it for coin hunting. Take a penny or dime and move it back and forth in all directions and various depth levels determining the cone effect, the coil effects at shallow distances, sensitivity around the coil edges and how to adjust your detector for its best depth. Turning the coin on its edge and doing the same movements will also help with understanding the signals from coins turned on edge in the ground.

Another great help with your metal detector is field tests found in treasure magazines or online. Experienced users making a field test on the same model detector that you own can add to your knowledge. Metal detector forums online also provide informative comments on detector use. There are also some great metal detector dealerships that offer assistance with training on detectors that they sell.