In this article, I will show you how to wind a metal detector coil yourself. Let's take this metal detector as an example. The coil in it must wind with a certain accuracy, but how can this be done common man who understands nothing about this ?? To help us, the greatest minds have created an interesting program (Coil32) who does not have a program, download it at the end of the article.

And so, on the diagram of the metal detector it is written that the coil must have an inductance of 2290mkH (microhenry). It even says what wire and on what diameter to wind. But if I want a coil larger diameter or smaller or the wire is of the wrong thickness ??

Then turn on our program (Coil32)

In the open program, press (PLUGINS) then (Multi loop) exactly where the coils we need will be.

A window like this will pop up:

Now everything is simple, everything is signed in the windows, what is the diameter of the wire, on which frame to wind and, most importantly, the window with inductance. We insert our parameters into the windows: we need an inductance of 2290 mkH, I had a wire of 0.4, and I want to wind the coil on a mandrel 11cm (111mm). As soon as all the values ​​are set, we press the calculate button and the information we need will appear in the window on the right.

So now you can independently calculate and wind a coil of any diameter that suits you best.

The main advantage possessed by impulse devices for searching for objects made of non-ferrous metal is that it is quite simple to build a coil for a twisted pair metal detector. Equipped with a fairly simple coil, these devices have excellent detection rates. This article will describe detailed instructions creation twisted pair coils for Pirate metal detector, thanks to which you can make this design yourself. Thanks to this, you will not need to purchase it on the radio market for a rather impressive amount. In the process of work, you will need standard elements, which are probably available from every electronics engineer. The coils, which are created by the following simple methods, can be used with almost all impulse devices that are very popular today.

Coil for Pulse Twisted Pair Metal Detector

From a twisted pair of wires, it is possible to build a wonderful sensor, which is an indispensable component for a pulse device. Such a coil will have a search depth of more than one and a half meters. This design It has good sensitivity to various small-sized products, which include gold jewelry, trifles, etc. In order to make such a coil, you need to first prepare a twisted pair wire, which can be purchased without any problems wherever radios are sold. The wire is made of four twisted pairs without a screen, it is very important that it be copper, not bimetallic

In order to make such a coil, you need to follow these instructions:
· Make a piece of wire that is 2.7 meters long.
· Mark exactly half of the line. After that, you should also measure 41 cm from each end.
· According to the marks made, you need to make a ring from this wire and fix it using ordinary tape or adhesive tape.
· The ends of the future coil should be slightly bent inward.

· This is followed by a thorough stripping of the wire insulation, after which you need to solder these wires in this order:

· After the above procedure, it is necessary to isolate the adhesions using special thermal tubes or adhesive tape.

· In order to draw the conclusion of the coil being produced, you need to take a 2 * 0.75 mm wire, which is in rubber insulation and has a length of 1.2 meters, and then solder it to the other ends of the future coil. After that, it is also necessary to insulate the wires.
· Decide on the most suitable coil body. You can easily purchase a factory product, or a regular plate made of plastic will do.

· The coil must be inserted into the body and the elements must be fixed using hot melt glue. The spikes and wires will also need to be secured.
· The next step is to glue the body. In the event that you did not use a ready-made body, but a plastic plate, then to make it more rigid, you must fill it with epoxy resin. First, you still need to conduct a trial test of functionality, because after you glue everything together, you will not be able to make amendments.
· In order to fix the coil to the shaft, you can use the factory bracket or come up with an analogue yourself, it all depends on your choice.
· After soldering the connector to the other end of the wire, the coil will be completely ready for use.

One of the advantages of impulse metal detectors is the simplicity of manufacturing search coils for them.... At the same time, with a simple coil, impulse metal detectors have a good detection depth. This article will describe the most simple and available ways making search coils for pulse metal detectors with your own hands.

Coils made by the manufacturing methods described below are suitable for almost all popular schemes of impulse metal detectors (Koschey, Clone, Tracker, Pirate, etc.).

1. Coil for Pulse Twisted Pair Metal Detector

From a twisted pair wire, you can get an excellent sensor for pulse metal detectors. Such a coil will have a search depth of more than 1.5 meters and have good sensitivity to small objects (Coins, rings, etc.). To make it, you need a twisted pair wire (such a wire is used for Internet connection and is available for sale in any market and computer store). The wire consists of 4 twisted pairs of wires without screen!

The sequence of manufacturing a coil for a pulse metal detector, from a twisted pair wire:

• Cut off 2.7 meters of wire.
• Find the middle of our piece (135 cm) and mark it. Then we measure 41 cm from it and also put marks.
• We connect the wire along the marks into a ring, as shown in the figure below, and fix it with tape or electrical tape.

• Now we begin to wrap the ends around the ring. We do this simultaneously on both sides, and make sure that the turns fit tightly, without gaps. As a result, you get a ring of 3 turns. This is how you should get it:

• We fix the resulting ring with tape. And bend the ends of our coil inward.
• Then we strip the insulation of the wires, and we solder our wires, in the following sequence:

• We isolate the soldering points with thermal tubes or electrical tape.

• To output the coil, we take a wire 2 * 0.5 or 2 * 0.75 mm in rubber insulation, 1.2 meters long, and solder it to the remaining ends of the coil and also insulate it.
• Then you need to choose a suitable housing for the coil, you can buy it ready-made, or choose a suitable diameter plastic plate etc.
• We put the coil in the case and fix it there with hot melt glue, we also fix our spikes and wires to the terminals. You should get something like this:

• Then the body is glued, or if you used a plastic plate or pallet, then it is better to fill it with epoxy, this will give your structure additional rigidity. Before glueing the body or filling it with epoxy, it is better to carry out intermediate performance tests! Since after gluing, there is nothing to fix!
• To attach the coil to the rod of the metal detector, you can use such a bracket (it is quite inexpensive), or you can make a similar one yourself.

• We solder the connector to the second end of the wire, and our coil is ready for use.

When testing such a coil from the Koschey 5I metal detectors, the following data were obtained:

• Iron gates - 190 cm
• Hard hat - 85 cm
• 5 braid coin of the USSR - 30 cm.

1. A large coil for a pulse metal detector with your own hands.

Here we will describe the way making a deep coil 50 * 70 cm, for impulse metal detectors... This coil is well suited for finding large metal targets on great depth, but it is not suitable for finding small metal.

So, the process of making a coil for pulse metal detectors:

• We make a pattern. To do this, in any graphics program, we draw our pattern, and print it in a 1: 1 size.

• Using a piece, we draw the outline of our coil on a sheet of plywood or chipboard.
• We drive in nails around the perimeter, or screw in the screws (the screws must be wrapped with electrical tape so that they do not scratch the wire), in steps of 5-10 cm.
• Then we wind the winding on them (for the Clone metal detector 18 -19 turns) of the 0.7-0.8mm winding enamel wire, you can also use a stranded insulated wire, but then the weight of the coil will turn out a little more.
• Between the studs, tighten the winding with cable ties, or tape. And we coat the free areas with epoxy resin.

• After the epoxy has hardened, take out the nails and remove the coil. We remove our screeds. We solder the conclusions from the stranded wire 1.5 meters long. And we wrap the coil with fiberglass, with epoxy resin.

• To make a cross, you can use polypropylene pipe with a diameter of 20 mm. These pipes are sold under the name Heat Seal Tubes.

• You can work with polypropylene using an industrial hair dryer. It must be heated very carefully, because at 280 degrees the material decomposes. So, we take two pieces of pipe, from one of them we heat the middle, dig a hole through and through, expand it so that the second pipe can fit into it, heat the middle of this very second pipe (while continuing to maintain the middle of the first in a hot state) and insert one into the other. Despite the complex description, it does not require any special dexterity - I did it right the first time. Two preheated pieces of polypropylene stick together "to death", you don't have to worry about their strength.
• We warm up the ends of the cross and cut them with scissors (heated polypropylene is cut well) in order to obtain “recesses” for the winding. Then we insert the crosspiece inside the winding and, alternately heating the ends of the crosspiece with the recesses, "seal" the winding into the latter. When putting the winding on the crosspiece, you can pass the cable through one of the pipes of the crosspiece.
• From a piece of the same pipe we make a plate (by flattening in a hot state), bend it with the letter "P" and weld it (again hot) to the middle of the cross. We drill holes for everyone's favorite bolts from the toilet lid.
• In order to give additional strength and tightness, we seal up the remaining cracks with all kinds of sealants, we wrap up doubtful places with fiberglass with epoxy, and finally, we wrap everything with electrical tape.

(in the footsteps of the md4 forum)

Any IB without a good sensor is practically just a pile of metal debris ...

Therefore, today's topic is IB , and its main unit is the DD sensor.

So, in order not to talk for a long time about the manufacturing methods and which one is better ..., I immediately post good information with pictures from the MD4 forum. Topic - "Making a stable DD coil" by syava7... Of course, I edited the topic for "superfluous" ... And so, let's go.

... We take a conventional commercial housing for a reel with hollow ears. Cut out from the PCB thickness. 2mm inserts into the ears as in the photo, the overhang should be about 7-8mm above the inner surface of the case, cut out small pieces of fabric for sealing. Coarse skin skins inner surface ears.

We saturate the fabric with epoxy, insert it with textolite into the ears. It should look like this:

When it dries up, lightly sand the entire body (inside), put a pressure seal, attach the body wire (ground) ...

Then we apply graphite mixed on Dragon(such a varnish), and it sticks tightly. but it remains elastic, it does not crack even with several bends of 90 degrees or more, so the wiring is quite enough.

Note: The Dragon I dilute 1: 1 with alcohol (otherwise it is very thick).

Resistance from wiring to any point is not more than 1 kOhm. I knead on the Dragon, sticks tightly, but at the same time is elastic. Do not smear the protruding ears.

While this whole thing dries, we wind the windings and do not tie them tightly with threads.

I take an audio-video cable S-VHS 2 cores in separate screens, cable diameter 6 mm. Sealed gland type PG-7.

... Then we put the windings into the coil. For centering and so that the winding does not touch the graphite, I use pieces of fabric about 1 cm wide in the narrow parts of the case, it lies in a semicircle and holds the winding, in the center there are just strips of fabric. We glue the resonant capacitors (necessarily film!), We connect everything, set it up, at several points we glue the windings with hot melt glue. everything looks like this:

Since the windings are not tightly wound, it is easy to flatten them at the intersection points, thereby reducing protrusion. ALWAYS put a piece of fabric between the windings!

This is how a fully assembled and tuned coil looks like before pouring. Yes, we do not forget to leave the tail of the wire from the coil screen.

Next, we prepare a table for pouring, I use a piece of chipboard, we find a place so that there is no metal nearby, I live in a high-rise building, and metal is everywhere, so I take a stool, put two shoe boxes on it (so that higher from the floor, on iron in the floor also reacts) to the chipboard bed, I set the plane along building level... The table is ready.

Since the ears are hard (about 1mm stroke), so that there are no nuances with the mounting of the coil on the rod, I insert an insert between the ears that fully corresponds to the mount on the rod and press, sometimes burst, it all depends on the case, because plastic

Since the plastic cases are often not entirely even, I take packs of matches, they are quite dense and of the same size, I substitute them in several places under the case, then I check the balance, and pour in one pass just above the edges of the windings. Then I put a book on top so that the body is leveled, the balance goes away a little from this, I correct the windings with a toothpick (I balance it). I make a suggestion to my wife and children so that no, no, otherwise ... And I wait until everything freezes. During the hardening of the epoxy, the balance floats away, in no case should it be corrected! After freezing, it will snap into place, and if you correct it, it will run away, it is not clear where ...

As a result, a smooth body with a minimum of epoxy is obtained, the windings are completely impregnated, no rustles, noises, microphone effects.

After mixing and pouring, epoxy gives a lot of air bubbles, which can be easily removed with a hairdryer or a gas burner (carefully!). For greater fluidity, you can add a little alcohol to the epoxy. But this epoxy dries longer !!!

Photos will be, as there will be an opportunity to finish all this. There is such a ready-made one, but nothing is visible there ...

Next, sand the epoxy a little so that the graphite better lime, glue the protruding screen wires, apply graphite, dry, pour a protective layer of epoxy 3-4 mm and the sensor is ready. I'd like to add that in last layer epoxy, you can add a little black dye or car paint and mix well ... The layer will turn out to be beautiful and opaque. PLUS - this layer will not drink water and is less susceptible to UV light.

Sewing off the excess height of the edges of the plastic sensor, and we get an excellent, lightweight (on the DD-30 540-560gr, depends on the weight of the windings), reliable and phantomless coil at home.

I make the screen without side walls, but only from the bottom and top, since the epoxy does not stick well to the graphite, and it is good to the sanded sides. The reel works stably on wet grass, etc.

Temperature stability depends on the coils, and if done correctly: Px is 2 kHz lower in frequency from Tx, and even the Q-factor of Px is lowered by the input resistor, then a good and stable coil is obtained.

Usually all my detectors work with search sensors:

Frequency……………. 8-10kHz.

Tx …………………… 40-45 turns with 0.45-0.56mm wire.

Рх …………………… 160-180 turns with 0.23-0.27mm wire.

I tune Px lower in frequency by 1.8-2 kHz in order to get to the gentle section of the frequency response and phase response. In reality, at a Tx current of 140-160 mA and a temperature from +35 to + 5, the amplitude at the output of the amplifier with a coefficient. mustache about 50 does not exceed 0.8 V. from + 5 to -5 no more than 1.2 V., which fits into the framework of any metal detector and the phase stands rooted to the spot.

I would be glad if I could help you, assemble a good sensor and .

Good luck with your design and search!

Alexander Serbin (Kharkov)

Nothing meaningful names for the uninitiated person: butterfly, ellipse, "sniper" - always attract the attention of a seeker of valuable metals. Metal detector coils can completely ruin the trip to the excavation or endow their owner with positive emotions and valuable finds.

The coil is a periscope, only all observations take place underground. Each metal detector has its own standard coil, and for a beginner digger it is enough for the first time. But then, to get better result search, you will need to have several types of different coils in your arsenal.

Search coils

There is no universal metal detector coil. For each specific location of departure, a special device is needed in order for the search to be successful. It should always be remembered that a large number of treasure hunters walk in the same areas as you, and it becomes difficult to find a secluded place. What is needed is a coil that can spot what competitors have failed to find. When choosing it, you should consider:

• the location of the place where the search will be carried out;
• probable finds;
• the presence of debris;
• soil mineralization.

Metal detector coils large sizes covering a wide area, in places with a lot of rubbish will not bring pleasure in searching. And it is convenient to work with small "snipers" in such a place. The criteria for the search coils are:

• size size - small, medium, large;
• shape type - butterfly, ellipse, circle;
• frequency (the number of waves that are sent into the ground to find metal) - high for small targets, low for large targets.

Which coil to buy?

The acquisition of the coil, as well as the metal detector itself, is a responsible business. The generic models that come with the detector are great for a start, but in the future, variations will be required to work in different terrain. It is necessary to determine the location of the search in order to choose the appropriate size and shape of the coil.

Ideally, you should have several different ones in order to always be in full readiness, since it is possible to change several search places in a day. An outdated detector does not have to be replaced 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 a partner manufacturer recommended by the supplier. When buying, do not forget to pay attention to the warranty service.

Metal detector Garrett ACE 250

This metal detector is the undisputed leader in Russian market... The device has a reliable circuit, high-quality performance, an excellent combination of price and search performance. He showed himself excellently among a wide range of search engines. The detector is produced by the American company Garrett, which is a leading company. The following additional functions distinguish it from the previously released one:

• Pinpointer. He gives the most accurate information about finding a find underground. And this helps to avoid digging large pits and save time and energy.
• Wide range of discrimination. The metal detector contains 12 sectors independent of each other for detecting metal. Depending on the algorithms, they receive information about the shape, material, conductivity of the object. For comparison: the previous Garrett ACE 150 detector contained only 5 sectors. This means that each signal from a new device is more informative.

The principle of operation of a simple metal detector Garrett ACE 250 allows anyone with no experience to quickly learn how to use it and enjoy their hobbies. It is this detector, as the easiest to use, that has gained great popularity among search engines.

Garrett ACE 250 Product Description

The device is manufactured according to modern technologies, similar to those used in more expensive models... It is easy to set up and operate, has high sensitivity, 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 select the type of metal you want (silver, copper, gold), rather than pulling debris out of the 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;
• only jewelry;
• 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.

Coil types

The metal detector coil has two loops:

• Transmitting - produces an electromagnetic field.
• Host - monitors field changes. The field begins to deform when metal object falls under the coil. The resulting distortions allow the operator to start searching for the subject.

Coils are of the following types:

1. Concentric. The loops (receiving and transmitting) are spaced as far apart as possible. As a result, a symmetrical field is created, which makes it possible to better separate finds that lie next to each other in a single run. The field is shaped like a cone. The concentric coil of the metal detector is designed for the entire set of existing finds. They are susceptible to increased soil mineralization.
2. Mono. It is used on a pulse metal detector. The receiving and transmitting loops are located side by side. Has the same properties as concentric.
3. Imaging. The special feature of this coil is the additional receiving loop. This allows the detector to identify the find most accurately.
4. DD. The coil is used to search for non-ferrous metals. It has good sensitivity to small finds. The coil field is shaped like a flat bucket to provide consistent visibility at different depths. Resistant to high soil mineralization.

Coil shape

Metal detector coils differ in shape by:

• Ellipsoidal. They share well-placed targets. The pinpoint mode is more accurate on elliptical coils, and they allow you to search for objects in dirty areas.
• Round. These coils allow you to identify an object at a deeper depth than ellipsoidal.

DIY metal detector coil

It is not difficult to make a coil on your own, since it does not require great precision in manufacturing.

1. A mandrel is required to wind the coil. To do this, take a plate and draw a circle or the Latin letter D on its surface. Small carnations are stuffed along the perimeter of the figure.
2. For the transmitting coil, take a small length of copper wire, the diameter of which is 0.45-0.6 mm, and wind the mandrel 25 times. The receiving coil is made in the same way, only the copper wire is taken with a diameter of 0.2 mm.
3. Tie the coils with a thread every one and a half centimeters and remove from the mandrel.
4. Impregnate the turns using epoxy resin or varnish.
5. Dry the product well within 24 hours.
6. Wrap the coils with electrical tape or FUM tape.
7. Make shielding of products by wrapping them with thin foil.
8. Wrap a wire without insulation on top of the foil, preferably tinned to improve electrical conductivity.
9. The coil body of the metal detector can be made of foam or expanded polystyrene. For strength, its outer and inner surfaces are reinforced.
10. Make grooves on the reel using a cutter. The depth of the grooves should be such that, after submerging them from above, it is possible to fill the coils with epoxy.

So, the homemade metal detector coil is ready and placed in the case.

Quick coil repair

Sometimes, by unsuccessfully waving the device, you can hit the coil on a stone or tree roots. The metal detector starts screaming, and a chip appears on the coil. Such a defect must be filled with epoxy, and the detector will still function properly. Experienced search engines advise in a hardware store to buy epoxy resin in the form of a pencil or two syringes and always carry it with you. When a chip appears, fill it with glue and continue searching after a few hours. Most importantly, you need to wait a certain amount of time for the resin to harden. It is best to repair the metal detector coil in the evening, and in the morning wrap the chip area with electrical tape for additional protection, and you can work.

For faster repairs, you can use superglue. It solidifies much faster. The treasure hunter should always have a tube of superglue, bicycle tube strips (several pieces) and a medical tourniquet in his backpack. Noticing the chip, you need to carefully remove the dirt from it, drip a few drops of glue, after two minutes, tighten this place tightly with a tourniquet, capturing the undamaged places of the coil, and stick the camera strip 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 keep the product in proper shape, you can buy protection for the metal detector coil or make it yourself from improvised means, for example, wrap it with electrical tape or thick cloth, attach the bottom of a plastic bucket to the outer surface.

Conclusion

You should not rush to change a metal detector if it is not technically outdated yet, has several detection frequencies and is tuned to the ground.

Minor additions will make it possible to increase its sensitivity and depth of detection of objects.