Insignificant names for an uninitiated person: butterfly, ellipse, “sniper” - always attract the attention of a seeker of precious metals. Coils of metal detectors can completely ruin a trip to an excavation or give their owner positive emotions and valuable finds.
The coil is a periscope, only all observations occur underground. Each metal detector has its own full-time coil, and for a first time a beginner digger it is enough. But then, to get a better search result, you will need to have several types of different coils in your arsenal.
Search Coils
There is no universal coil for a metal detector. For each specific place of departure, a special device is necessary for the search to be successful. You should always remember that a considerable number of treasure hunters walk in the same areas as you, and it becomes difficult to find a secluded place. You need a coil that could notice what competitors were unable to find. When choosing it, you should consider:
- location of the place where the search will be performed;
- probable finds;
- the presence of garbage;
- mineralization of the soil.
Large-sized metal detector coils covering an extensive area in areas with lots of debris will not bring pleasure in the search. And it’s convenient to work with small “snipers” in such a place. The search coils criteria are:
- size size - small, medium, large;
- type of form - butterfly, ellipse, circle;
- frequency (the number of waves that are sent to the ground to find metal) is high for finding small targets, low for large ones.
Which reel to buy?
The acquisition of a coil, as well as the metal detector itself, is a responsible matter. Typical models that come with a metal detector are great for a start, but in the future, to work on different terrain, their variations will be required. It is necessary to determine the place of search in order to choose the appropriate size and shape of the coil.
In the ideal case, you should have several different ones, to always be in full readiness, since it is possible to change several places of search in a day. It is not necessary to replace an outdated detector with a new one; it is cheaper to purchase a coil for it. It is safer to buy a product of the same brand as the metal detector, or from the partner manufacturer recommended by the supplier. When buying, do not forget to pay attention to warranty service.
Garrett ACE 250 metal detector
This metal detector is the undisputed leader in the Russian market. The device has a reliable circuit, high-quality performance, an excellent combination of price with search characteristics. He proved himself perfectly among a wide range of search engines. The detector is released by the American company Garrett, which is a leading firm. The following additional features set it apart from the previously released Garrett ACE 150 :
- Pinpointer. It gives the most accurate information about finding the find underground. And this helps to avoid digging large pits and save time and energy.
- Wide scale discrimination. The metal detector contains 12 sectors independent from each other for metal detection. Depending on the algorithms, they receive information about the shape, material, conductivity of the subject. For comparison: the previous Garrett ACE 150 detector contained only 5 sectors. This means that each signal of the new device is more informative.
The principle of operation of a simple Garrett ACE 250 metal detector enables anyone who does not have any experience to quickly learn how to use it and enjoy a hobby. It is this detector, as the easiest to use, among the search engines has gained great popularity.
Product Description Garrett ACE 250
The device is manufactured using modern technologies similar to those used in more expensive models. It is simple to configure and manage, has high sensitivity, and quickly responds to the target. The Garrett metal detector has the ability to search in the "all metals" and "discrimination" mode, which allows you to choose the type of metal you need (silver, copper, gold), and not pull out garbage from iron. The weight of the device is a little more than a kilogram, it lies comfortably in the hand, and it is convenient to work with it. The metal detector contains the following modes:
- any metals;
- jewelry only;
- relics;
- all coins;
- custom.
Using the modes of a simple metal detector, the user can quickly and conveniently search for certain objects, filtering out unnecessary signals. In addition, the operator can specify his mode of operation.
Types of Coils
The coil for the metal detector has two loops:
- Transmitting - produces an electromagnetic field.
- Host - monitors field changes. The field begins to deform when a metal object falls under the coil. The resulting distortion allows the operator to start searching for an item.
Coils are of the following types:
- Concentric The loops (receiving and transmitting) are spaced as far apart as possible. As a result of this, a symmetrical field is created, which makes it possible to better separate the finds that lie nearby in one wiring. The field has the shape of a cone. The concentric metal detector coil is designed for the entire set of existing finds. They are affected by increased soil mineralization.
- Mono. It is used on a pulsed metal detector. The receiving and transmitting loops are located nearby. It has the same properties as concentric.
- Imaging. A feature of this coil is an additional receiving loop. This allows the detector to most accurately determine the find.
- DD. The coil is used to search for non-ferrous metals. She has good sensitivity to small finds. The coil field has the shape of a flat bucket, which provides the same visibility at different depths. Not subject to the effects of high mineralization of the soil.
Coil shape
The detector coils in shape differ in:
- Ellipsoidal. They well share the goals located nearby. The accuracy of the pinpoint mode on the coils in the shape of an ellipse is higher, and they allow you to search for objects in contaminated areas.
- Round. These coils allow you to determine the subject at a greater depth than ellipsoidal.
DIY metal detector coil
It is not difficult to make a coil on your own, since it does not require great accuracy in manufacturing.
- A mandrel will be required to wind the coil. To do this, take a plank and draw a circle or the Latin letter D on its surface. Small cloves are stuffed around the perimeter of the figure.
- For the transmitting coil, take a small length of copper wire, the diameter of which is 0.45-0.6 mm, and wrap the mandrel 25 times. Do-it-yourself receiving coil for a metal detector is done similarly, only copper wire is taken with a diameter of 0.2 mm.
- Tie the coils with a thread every one and a half centimeters and remove from the mandrel.
- Impregnate coils using epoxy resin or varnish.
- Dry the product well during the day.
- Coil the coils with electrical tape or tape FUM.
- Make shielding of products by wrapping them with thin foil.
- Wrap a wire without insulation on top of the foil, preferably tinned to improve electrical conductivity.
- The detector coil body can be made of polystyrene foam or expanded polystyrene. For strength, its outer and inner surfaces are reinforced.
- Make reel grooves using roller cutter. The depth of the grooves should be such that after they are immersed on top, it is possible to fill the coils with epoxy resin.
So, the homemade coil for the metal detector is ready and placed in the case.
Quick coil repair
Sometimes, unsuccessfully waving a device, you can hit a coil on a stone or tree roots. The metal detector begins to "scream", and a chip appears on the coil. Such a defect must be filled with epoxy resin, and the detector will still work properly. Experienced search engines advise in a hardware store to buy an epoxy resin in the form of a pencil or two syringes and always carry it with you. When a chip appears, pour it with glue and after a few hours continue the search. Most importantly, you have to wait a certain time for the resin to freeze. It is best to repair the detector coil in the evening, and in the morning place the cleavage with electrical tape for additional protection, and you can work.
For faster repairs, you can use superglue. It freezes much faster. In the backpack, the treasure hunter should always have a tube of superglue, strips from the bicycle chamber (several pieces) and a medical tourniquet. When you notice a chip, you need to carefully remove the dirt from it, drip a few drops of glue, tighten it tightly with a tourniquet after two minutes, capturing the undamaged parts of the coil, and stick a strip of the camera on the same glue. This, of course, is a temporary repair, but it allows you to use the metal detector for another two days. At home, the coil can be repaired more thoroughly. To save the product in its proper form, you can buy protection on the coil of a metal detector or make it yourself from improvised means, for example, wrap it with electrical tape or a dense cloth, attach the bottom of a plastic bucket to the outer surface.
Conclusion
Do not rush to change the metal detector if it is not technically outdated yet, it has several detection frequencies and there is a setting for the soil.
Minor additions will make it possible to increase its sensitivity and depth of detection of objects.