Finding artifacts underground is a fairly popular activity. For some, this is a profession, others are simply interested in archaeology. There are numerous groups of treasure hunters: both romantics and pragmatic treasure hunters. All these people are united by one passion: searching for metal objects hidden at various depths.

If you have accurate map indicating the location of the burial of the treasure, or plans for fighting during the war, this does not guarantee success. You can shovel tons of soil, and the desired item will calmly lie a couple of meters from the active search site.

To search for gold and less valuable metals, you will need a metal detector that you can make yourself.

Important information: The use of such devices is not prohibited by law. However, there are penalties for the consequences of such a search regarding excavations, as well as the recovery of discovered objects.

We won’t go into details; that’s the topic of another article. Simply put: if you find gold ring on the beach, or a handful of Soviet coins in the forest - there will be no problems associated with the use of electronic search tools.

But for recovered bronze spoons that are 100 years old or older, you can get a real sentence or a large fine.

Nevertheless, devices for searching for metal objects in the depths of the earth are freely sold, and those who want to save money can make a metal detector with their own hands at home.

How the device works

Unlike ground detectors, which work using waves of different frequencies or ultrasound, a metal detector (either factory-made or home-made) works with inductance.

The coil emits an electromagnetic field, which is then analyzed by the receiver. If any object that conducts electric current or has ferromagnetic properties is in the coverage area, the field format is distorted. More precisely, under the influence of the active field of the coil, the object forms its own. This event is recorded by the receiver, and an alert is generated: the instrument needle moves, a tone sounds, and indicator lights light up.

Knowing the operating methodology, you can calculate the electrical circuit and create powerful metal detector with your own hands. The complexity of the design depends only on the availability of the element base and your desire. Let's look at several popular options for how to assemble homemade metal detector:

The so-called "butterfly"

This nickname was received due to the characteristic shape of the platform on which the inductors are located.

The arrangement of the elements is related to the operating principle. The circuit is made in the form of two generators operating at the same frequency. When identical coils are connected to them, an induction balance is created. As soon as a foreign object with electrical conductivity gets into the electromagnetic field, the balance of the field is destroyed.

Generators are implemented on NE555 chips. The illustration shows typical diagram such a device.

The coil for the metal detector (there are two of them, in the diagram: L1 and L2) is made by hand from wire with a cross section of 0.5–0.7 mm². Ideal option- transformer winding copper core in varnish insulation (removed from any unnecessary transformer). The characteristics do not have to be maintained with pinpoint precision, under one condition: the coils must be identical.

Approximate parameters: diameter 190 mm, each coil has exactly 30 turns. The assembled product must be monolithic. To do this, the turns are grabbed with a mounting thread and filled with transformer varnish. If this is not done, vibration of the turns will throw the circuit off balance.

Electrical diagram

There are two manufacturing options:

• given the small number of elements, you can assemble it on a breadboard by connecting the legs of the parts using conductors;
• For accuracy and reliability, it is better to etch the board according to the proposed drawing.

Any “snot-based” soldering can fail in the field, and you will be offended for wasted time.

Just like a transistor metal detector, the NE555 device needs fine tuning before use. The diagram shows three variable resistors:

• R1 is designed to adjust the frequency of the generator and achieve that same balance;
• R2 coarsely adjusts sensitivity;
• Using resistor R3, you can set the sensitivity with an accuracy of 1 cm.

Information: This scheme cannot discriminate against metals. The seeker only makes it clear that the object exists. And by the tone of the signal (based on your experience) you can determine the approximate volume and depth of the deposit.

The power supply is quite universal: 9–12 volts. You can select the battery from the source uninterruptible power supply, or assemble a power supply from AAA batteries. A good option is 18650 batteries (they are also used for vaping).

Butterfly setting

The principle of operation is described above, so let’s just look at the technology. We set all resistors to the middle position, and ensure that the synchronization of the generators is disrupted. To do this, we fold the coils in a figure eight and move them relative to each other until the squeaking turns into crackling. This is a synchronization failure.

We fix the rings and rotate the resistor R1 until a steady crackling sound appears at even intervals.

By bringing metal objects to the place where the coils overlap (this is the search point), achieve a steady squeak. The sensitivity is adjusted by resistor R2.

All that remains is adjustment with resistor R3, which is used rather to correct the voltage drop in the power source.

Mechanical part

A do-it-yourself metal detector rod is made from lightweight plastic pipes or wood. The use of aluminum is undesirable as it will interfere with operation. The circuit and controls can be hidden in a sealed housing (for example, a junction box for wiring).

The butterfly finder is ready to go.

Pirate

Another popular pulse model for beginner treasure hunters is the “Pirate” metal detector. It is also easy to make with your own hands, detailed instructions in two versions:

It is advisable to bring the power closer to 12 volts, since the quality of work depends on the voltage. Printed circuit boards have already been tested, both options are shown in the illustration.

Coil (in in this case one) is made from the same 0.5 mm transformer wire. The optimal diameter is 20 mm, the number of turns is 25. Since we are making the “Pirate” metal detector with our own hands, the external design fades into the background. Any materials that you were ready to throw away will do.

It is better to make the handle detachable for ease of transportation. We remember that the use of metals is unacceptable.

Sensitivity is adjusted by two variable resistors in real time while searching. No fine tuning of the generator is required.

And if you manage to properly seal the case, you can start searching for “treasures” in the beach surf, and even at the bottom of the reservoir.

It is more difficult to make an underwater metal detector with your own hands, but it will give you an undeniable advantage over your competitors.

Improved performance

You can make a deep metal detector with your own hands from a ready-made “Pirate” without additional costs. There are two ways to do this:

1. Increasing the diameter of the inductor. At the same time, downward permeability increases significantly, but sensitivity to small objects decreases.
2. Reducing the number of coil turns while simultaneously adjusting the circuit. To do this, you will have to sacrifice one coil for experiments. We remove (and cut off) turn after turn until we see that the sensitivity begins to decrease. We remember the number of turns at maximum parameters, and make a new coil for this circuit. Then we change the resistor R7 to a variable one, with similar power parameters. After conducting several experiments with sensitivity, we fix the resistance and change the variable to a constant resistor.

The Pirate metal detector can be assembled using the popular Arduino controller.

It is more convenient to use such a device, but there will still be no discrimination of metals.

Having figured out how to make a metal detector with your own hands for amateur tasks, we will briefly examine several serious models.

DIY metal detector Clone PI W

In essence, this is a cheaper version of the professional finder Clone PI-AVR, only instead of an LCD display, a line of LEDs is used. This is not as convenient, but still allows you to control the depth of artifacts.

The best option for the price is the CD4066 chip and ATmega8 microcontroller.

Of course, there is also a printed circuit board layout for this solution, only the control buttons are placed on a separate panel.

Programming ATmega8 is a topic for a separate article; if you have worked with such controllers, no difficulties will arise.

The powerful Clone PI W metal detector, made by yourself, allows you to find metal no more than a meter deep, although without discrimination.

Seeker "Chance"

A similar circuit on the ATmega8 controller is called “Chance”. The principle of operation is similar, only the possibility of screening out (partial discrimination) of ferrous metals has become possible.

A printed circuit board design has also been worked out, which can be successfully replaced with a classic “breadboard” for Arduino

DIY Terminator 3

If you need a homemade metal detector with metal discrimination, pay attention to this model. The scheme is quite complicated, but your efforts pay off with the coins you find, which may turn out to be gold.

The peculiarity of the “Terminator” is the separation of the receiving and transmitting coils. A 200 mm ring is made to emit the signal. 30 turns of wire are laid for it, then it is cut, as a result we get 2 half-coils with a total capacity of 60 turns (see diagram).

The receiving coil is located inside, 48 turns with a diameter of 100 mm.

The adjustment is made using an oscilloscope; after achieving optimal amplitude results, the windings are fixed in the housing by pouring epoxy resin.

Then an experimental hands-on adjustment of the discrimination switch is performed. For this purpose, real objects from various metals, and their type is indicated on the mode switch (after checking).

Radio amateurs are working on an improved version of Terminator 4, but there is no practical copy yet.

Simple metal detectors from ready-made electrical appliances

Bottom line

Regardless of the complexity of the design, making a homemade metal detector will require a lot of time and effort from you. Therefore, out of curiosity, such devices are not made. But for professional use, this is an excellent alternative to factory copies.

Video on the topic

There is probably no need to tell you what this electronic device is intended for. Everything is clear to everyone. These devices are used by sappers, at airports, in intelligence agencies, and in various institutions related to security in one way or another. But that's not all.

Metal detector in the 90s

These devices in the 90s of the twentieth century helped people not to die of hunger. During those difficult times, you could often see young people and others walking the streets with metal detectors. The device was used to search for metals and alloys. In particular, in cities near which large industries were located, it was possible to dig up real wealth with its help.

Basically, these guys made metal detectors with their own hands and looked for waste from metallurgical plants or native metals that remained in the bowels of the earth. The latter were used in the construction of routes. After all, many asphalt and dirt roads were covered with slag, and often in its composition one could find metal and an alloy of iron and manganese - ferromanganese. At the end of the 90s, it had already become quite expensive. In one day of such work on city and country roads one could earn as much as a factory worker earned in a week. Since many people were unemployed, this activity became especially popular. After all, this alloy is one of the components for creating steel of various grades at the same metallurgical plants.

Metal detectors today

Today, the topic of searching with the help of electronic devices is not so widely developed. However, these devices are still popular among certain groups of people. They wander through the places of former glory of valiant Soviet soldiers, trying to dig up something valuable from historical objects. For example, you can find coins from the time of the Patriotic War, German ones of course. And some people manage to dig up really valuable things. You just need to know where to look.

What can you really find?

Unless you pick up the device yourself and walk along the city roads or through memorable and historical places, you will hardly believe how many interesting objects the earth stores. And for this you should build a metal detector with your own hands.

Coins

Often you can dig them up. During times Ancient Rus' Coins of the Arab East were used for trade. Then they used coins of Byzantine and Tatar production. Silver bullion is now found in the form of money.

Today in Crimea (and this is where well-preserved objects can be found) you can see people with these devices.

Crosses, icons, coils

Every self-respecting Christian wore a cross in Ancient Rus'. All crosses were different from each other, depending on the type and its purpose. You can often find so-called vests.

Buckles, buttons, various household items

This group of items is very numerous. Most of them have been used since the Bronze Age and are used until today. Often the objects were made of bronze, copper or iron.

Echoes of War

This is the most popular group of items that are searched for purposefully. They are especially popular among collectors. Enthusiasts are searching, getting them, and restoring them. Some end up in museums, some end up in your hands.

How to make a metal detector with your own hands

In the era of the popularity of ferromanganese and high prices for it, grimy young people did not shy away from digging in the ground to earn a little money. More often they purchased devices to search for their prey in numerous markets or from various specialists who, by chance, were fired from radio factories or TV repair shops. One way or another, these professionals assembled the metal detector with their own hands from radio components left in stores using various schemes and technologies. The guys often argued about who had the better and more technologically advanced device. After all, back then it was actually a working tool, and not a hobby device, as it is nowadays.

Those who had at least a little knowledge of electronics also made their own metal detectors. But these guys weren't interested in digging a metallurgical ingredient out of the ground. But it seems we have deviated from the topic.

Operating principle

Before moving on to assembling various circuits, you need to look at the operating principle of these devices.

The operation of a metal detector is based on the principles of magnetic attraction. The device creates a magnetic field through one coil. The second receives return signals. Then, if found, it sends a return signal through an audible alarm. You can even make a special metal detector for non-ferrous metals with your own hands.

How large sizes coil, the more sensitive the device will be. Although in modern devices, and especially in industrial models, the coil is small. But there are amplifiers on microcircuits.

Types

An ultra-low frequency finder is the simplest device. Every schoolchild knows how to make a metal detector with his own hands using an ultra-low frequency circuit. But this does not mean that such a seeker is ineffective. Quite the opposite. With proper setup, you can achieve good results.

The pulse finder is a deeper device. With its help you can easily find jewelry, coins and other small items at great depths. Such schemes are popular among professional treasure hunters.

A device that operates on beats allows you to detect absolutely any metal object or mineral in the bowels of the earth at a depth of up to a meter. It is designed for certain types of alloys. This is a cheap device to assemble.

The radio detector is capable of detecting metals at a depth of up to a meter. It's easy to do. This is a suitable device for beginners, but is not popular among diggers.

A primitive metal detector using one transistor

If you still have a long-wave radio receiver in working condition at home, then even if you have little knowledge of electronics, you can assemble a metal detector attachment for this receiver.

To make a metal detector with your own hands, the diagram is drawn without much difficulty. The circuit diagram represents the most common LC generator, designed for frequencies in the region of 140 KHz. The coil for the device, which is used as an oscillating circuit, should contain 16 turns of the simplest insulated wire up to 0.5 mm in diameter. The coils must be laid on plywood of suitable sizes. Fix the resulting contour to the base using glue. This is how you usually make a coil for a metal detector with your own hands.

Required Parts

You can use absolutely any resistors and capacitors for this device. As a transistor, a low-power high-frequency one with reverse conductivity will suffice. This could be the popular and easily available KT315. Or KT3102 with any letter index.

To assemble this simple metal detector with your own hands, the circuit is assembled either wall-mounted, or on a pre-prepared board made of getinax or textolite.

Setting up a simple metal detector

After the part is ready, we need to place it next to our coil. The device should have a comfortable handle. The radio receiver must be mounted on the finder handle, and then tuned to a frequency around 140 kHz. You will hear a squeak or squeak. If you bring the coil closer to a metal object, the sound in the headphones will change its tone.

Despite the fact that these are the simplest metal detectors in design and layout, making them with your own hands is elementary; the sensitivity of such devices makes it possible to work at depths of up to 200 mm.

High frequency finder

This assembly scheme is a little more complicated than the previous one. But also much more effective. Its difference is that there are two coils.

The first is the outer contour. A magnetic field is created directly in this coil. The second is the receiving circuit. This part is designed to receive, process, and amplify signals that come from the earth.

Making a deep metal detector with your own hands

First you need to collect the so-called command block. To create it, an old computer, an equally old laptop or a radio will do. Then you need to find the highest frequency in the AM band. You need to make sure that there is no radio station on the frequency.

Search head

To assemble the search head, you need to cut two circles from thin plywood. One of them should have a diameter of about 15 cm, the second should be made a little smaller. This is done so that the rings can be inserted into each other. Then we need to cut out small pieces of wood so that our head rings are parallel.

After this, 10-15 turns of enameled wire with a cross-section of 0.25 mm from the outer circle should be removed from the plates. You also need to secure the resulting structure. For everything to work, you need to connect the head from the bottom and the detector from the top.

It's time to turn on our frequency. A faint tonal sound will be heard. It's better to use headphones.

Metal detector "Pirate"

Assembling the device is not difficult at all. The device circuit does not contain programmable microcircuits; it is easy to make and configure this metal detector with your own hands. Detailed instructions will help with this. Also, this circuit does not contain expensive or scarce parts. "Pirate" in its parameters can surpass foreign, quite expensive industrial analogues.

Options

For power supply you will need from 9 to 12 V. The current consumed by the device is up to 40 mA. Sensitivity will be up to 150 cm subject to large metal objects.

How is the element base for a metal detector made?

The “Pirate” type circuit consists of two nodes. This is a transmitting circuit, which consists of a pulse generator based on KR1006VI1 and a switch made from an IRF740 transistor. The receiver is made on the basis of the K157UD2 microcircuit and the VS547 transistor.

The coil should have 190 mm in diameter. The number of turns on the PEV wire is 0.5 - 25. The transistor in the circuit can be pulled out of an ordinary energy-saving light bulb or any charger for mobile phones. A correctly assembled “Pirate” metal detector with your own hands practically does not need to be configured.

"Terminator"

The device has good capabilities. For example, the device will detect a coin with a denomination of 5 Russian rubles from 25 cm. The finder will recognize a German military helmet from 80 cm. These values ​​are given on the condition of a coil with a diameter of 240 mm. "Terminator" can recognize metals even at the maximum working depth.

It is worth saying that beginners are unlikely to be able to assemble a “Terminator” metal detector with their own hands. The device requires careful setup. Even experienced craftsmen sometimes mistakes are made when assembling this circuit. The main thing here is not to rush.

In order to assemble the Terminator, you will need a multimeter, as well as an oscilloscope and an LC meter. They are not available to every person. However, you can try to create a special software and hardware complex based on a regular home personal computer.

Description

The terminator is a single-tone device that operates from pulsed beats. The finder is great for finding coins. Also, if you make a little modification, you can look for gold on the beaches, while completely ignoring any other metals. "Terminator" is also suitable for searching for any other objects from any alloys.

In conclusion

So, we found out how to make a “Pirate” metal detector with our own hands, and also looked at “Terminator”. As you can see, by devoting a minimal amount of free time and effort to the assembly, you can get a rather interesting, and most importantly, workable tool with which you can find ancient objects, and possibly expensive coins.

A deep metal detector is similar in design to a regular one, with the exception of some technical details. It also differs in its increased sensitivity to metal objects, which makes it possible to detect them at greater depths compared to a simple metal detector. In addition, there is a selective search function, that is, the ability to find objects of a certain size without reacting to those that do not fit the parameters.

Diagram of a deep metal detector

It is quite simple, despite its apparent complexity. The metal detector consists of two parts – receiving and transmitting. The main device is a high frequency transmitter generator. Two loop antennas, one of which serves as a signal transmitter, the second as a receiver. They must be located strictly at an angle of 90 degrees to each other to prevent the receiving antenna from picking up the generator signals. When a metal object is found, the magnetic field created by the generator is distorted and subsequently picked up by the receiving antenna. In this case, the mass of a metal object is used as a source of radiation, sending the energy produced to the receiving antenna.

Metal detector receiver circuit

The transmitting device includes a thyristor with a power of 0.25 to 1 W and a sound generator with a frequency of 200 Hz. When a metal object is found, the operator hears a sound with a frequency of 200 Hz, the strength of which depends on the size of the object found and the distance to it.

A detector receiver whose oscillation circuit responds to a frequency of 120 kHz, and consists of two diodes. The amplifier can be absolutely any low-frequency generator that can be found in an old radio. An amplifier with transistors in the amount of 5-6 pieces is enough. A transistor is also used as a current amplifier for a pointer instrument, allowing the level of the received signal to be measured. That is, the device contains two types of indicators - visual and acoustic. The operating frequency is adjusted so as not to interfere with the operation of the signal receiver.

Transmitter circuit

Required parts and tools for assembly

To assemble such a metal detector, you must first prepare a set of necessary parts and tools.

In the case of a pulse metal detector, approximate parts list will look like this:

1. Electrolytic capacitors with a voltage of at least 16 V in the following capacities: 2 capacitors with a capacity of 10 μF, one with a capacity of 2200 μF, 2 pcs - 1 μF.
2. Ceramic capacitors: 1 piece with a capacity of 1 nf.
3. Film capacitors of the lowest voltage value, for example, 63 V - 2 pieces of 100 nf each.
4. Resistors of 0.125 W: 1 k - one, 1.6 k - one, 47 k - one, 62 k - two, 100 k - one, 120 k - one, 470 k - one, 2 ohm - one, 100 ohm – one, 470 ohm – one, 150 ohm – one,
5. Resistors of 0.25 W: 10 ohms - one.
6. Resistors 0.5 W: 390 ohm - one
7. Resistors 1 W: 220 ohm - one.
8. Variable resistors: 10 k – one, 100 k – one,
9. Transistors: BC 557 – one, BC 547 – one, IRF 740 – one,
10. Diodes: 1N4148 - two, 1N4007 - one.
11. Microcircuits: K157 UD2, NE555.
12. Panels for each of them.

Metal detector parts

From tools When performing work you will need:

• Soldering iron, tin, special solder, other soldering supplies.
• A set of screwdrivers, wire cutters, pliers and other plumbing tools.
• Materials for the production of printed circuit boards.

Metal detector assembly steps

The process of assembling a deep metal detector with your own hands includes the following steps:

At the first stage, it is necessary to assemble the electronic part, namely the control unit.

The step-by-step process looks like this:

• Cutting PCB to the required size.
• Preparing a PCB design and transferring it directly to the board.
• Preparation pickling solution. It contains table salt, electrolyte and hydrogen peroxide.
• Etching the board and drilling technological holes.
• Tinning the board using a soldering iron.
• Next comes the most important stage in the control unit assembly. This is the selection, search and soldering of parts directly onto the board.
• Winding a test coil. There are several options for winding it. The simplest option is to use a PEV wire of size 0.5 and wind it 25 turns on a suitable frame with a diameter of about 19-20 cm.

The best option would be to solder everything directly, and after the setup is complete, select the necessary connectors and adapters. It’s better not to do twists, it has negative influence on the sensitivity of the device.

The second good option would be to make such a ring from twisted pair wire. You will need about 2.5 - 2.7 m of wire.

To achieve maximum sensitivity, do the following:

1. Wind 25 turns of wire.
2. Perform a test by cutting small pieces of wire and observing the increase in sensitivity.
3. This must be done until sensitivity begins to decrease.
4. Count the number of turns, wind the final version of the coil, adding 1-2 turns. Thus, the maximum sensitivity value is achieved.

Upon completion of the main work, the control unit, coil and other parts are fixed in place on the rod. The metal detector can be turned on and checked.

Possible problems during assembly

• The assembled device does not react to metal objects. The cause may be a breakdown of the diodes or transistor. Faulty parts need to be replaced.
• Excessive heating of the transistor. You should install a resistor of lower resistance, reducing it until the heating stops.

Assembly of this type of metal detectors is not too difficult, provided all rules and instructions are strictly followed.

This type of design is designed to search for coins. The process of assembling it is completely simple. However, experience in assembling such a tool is still necessary. The Terminator is able to detect an object even if the target of capture is minimal.

First you need to prepare necessary equipment, namely:

• a multimeter that measures speed.
• LC meter
• Oscilloscope.

Next, you need to find a diagram broken down into nodes. Now you can make a printed circuit board into which jumpers, resistors, panels for microcircuits and other parts should be soldered in order. The next step is to clean the board with alcohol. It is definitely worth checking for defects. You can check whether the board is in working condition as follows:

1. Turn on the power.
2. Turn down the sensitivity control until no sound is heard from the speaker.
3. Touch the sensor connector with your fingers.
4. When turned on, the LED should blink and then go out.

If all actions occurred, then everything was done correctly. Now you can make a coil. It is necessary to prepare a winding enamel wire with a diameter of 0.4 mm, which must be folded in half. A circle is drawn on a sheet of plywood with a diameter of 200 mm and 100 mm. Now you need to drive nails in a circle, the distance between them should be 1 cm.

Next, you can move on to winding the turns. At 200 mm you should make 30 of them, and at 100 - 48. Then the first coil should be soaked in varnish; when it dries, you can wrap it with thread. The thread can be removed, and by soldering the middle, you get a solid winding of 60 turns. Afterwards, the coil must be wrapped with electrical tape quite tightly. And a 1 cm foil is placed on top, this will be a screen, and more electrical tape is wound on top of it. The ends should come out.

On the second coil it is also necessary to solder the middle. In order to start the generator, you need to connect the first coil to the board. The second coil should be wrapped with a wire of 20 turns, then we connect it to the board. Now you need to connect the oscilloscope minus to minus to the board, and the plus is connected to the coil. Be sure to look at what frequency it will be when you turn it on and remember it or write it down on paper.

Now the coils need to be placed in special form to then fill them with resin. Next, the oscilloscope is connected to the board, with the negative pole, the amplitude should reach zero. The coils in the mold are filled with resin to approximately half the depth. When everything is ready, the metal discrimination scale is adjusted.

Parts list for the Terminator 3 metal detector

As parts for the trio metal detector you will need:

If you have these parts, you can assemble the Terminator Pro metal detector yourself.

Circuit diagram of a metal detector with metal discrimination

You can make a metal detector with metal discrimination yourself using the circuit for the Chance pulse device. The process of making a coil is quite simple.

The diagram itself can be found on the Internet. But still, experience in assembling such devices will be useful. Assembling the metal detector should begin with the board.

After the board is manufactured, the microcontroller needs to be flashed. And at the end of the work, we connect the metal detection device to the power supply.

DIY metal detector without microcircuits

Homemade equipment can be made without complex microcircuits, but using a simple transistor generator. The metal detector will be non-discriminatory. It will detect objects in the ground to a depth of 20 centimeters, and in dry sand - to a depth of 30 centimeters. In this device, the transmitting and receiving coils operate simultaneously.

Terminator 3 metal detector coil

To begin with, you should take winding enamel with a diameter of 0.4 mm. Fold it so that there are two ends and two beginnings. Next, you should wind from two reels at a time.

Now we need to make transmitting and receiving coils; for this, two circles of 200 mm and 100 mm are drawn on a plywood sheet. Nails are driven in along these circles, the distance between them should be 1 cm. 30 turns of enamel wire are wound onto a large mandrel. Then you should apply varnish to the coil and wrap it with thread, then remove it from the winding and solder the middle. This creates one middle wire and two outer wires.

The resulting coil should be wrapped with electrical tape and a piece of foil should be placed on top, and foil on top again. The ends of the windings should go out.

Now it’s time to move on to the receiving coil. 48 turns are already wound here. To start the generator, you need to connect the transmitting coil to the board. The middle wire is connected to the negative. And the middle terminal of the take-up coil is not used. The transmitting coil requires a compensating coil, on which 20 turns are wound.

We connect the oscilloscope to the board like this: a probe with a minus to the minus of the board, and a plus probe to the coil. Be sure to measure the frequency of the coils and write it down.

After connecting the coils according to the diagram, they must be placed in a special container and filled with resin. The oscilloscope now sets the division time (10 ms and 1 volt per cell). Now you should reduce the amplitude to zero. We wind the turns until the volt value reaches zero. We make a compensating loop at the coil, which will be outside.

The mold should be filled halfway with resin. When everything hardens, you need to connect the oscilloscope and bend the loop inward. Then twist it until the amplitude value becomes minimal. Afterwards, you need to glue the loop, check the balance, and now you can fill the second half of the container with resin. The reel is ready for use.

Metal detector coil repair

Before you begin the repair, you should prepare the following tools:

• Stationery knife;
• Incandescent lamp;
• A container for glue, preferably flat;
• Special or epoxy resin;
• Medium and fine sandpaper;
• Small spatula.

First of all, you need to dry the coil using an incandescent lamp. And use a utility knife to widen the cracks on it. Squeeze glue onto flat surface and mix with a spatula. Apply this substance to the coil. In places of cracks, you can apply more resin. Now you should wait until it all hardens thoroughly. And then sand it, using first medium and then fine sandpaper. This procedure will help smooth out all the unevenness. In this fairly simple way, you can revive the oldest coil from a metal detecting device.

Parameters of metal detectors depending on purpose and technical device

Metal detectors for amateurs are the simplest dynamic type devices. The search head of the device must constantly move; this is the only way the desired signal can appear. If you stop moving, the signal will disappear. Such simple detectors are convenient because they do not require complex settings and allow you to exclude medium soils. Disadvantages include its low sensitivity and frequent false alarms in difficult areas.

The scanning speed of the device is about 30 centimeters per second.

Mid-range devices have better sensitivity. This device is supplied with several search heads from the factory. different sizes. Setting up the detector will require certain skills. Mid-range metal detectors are capable of recognizing metals.

Computerized devices are already professional instruments with a liquid crystal screen and pointer indication. The memory of its processor is loaded with programs capable of recognizing and distinguishing a signal and classifying each detected object. Professionals independently program devices for search conditions, eliminating unwanted triggers.

Gold detecting tools work not only on coins and jewelry in the ground, but also on native metal. It is not suitable for searching for small particles such as sand. It does not recognize them, especially if the soil is highly mineralized.

Otherwise, these metal detectors are very sensitive and work great, for example, when searching for gold jewelry in the sand of the beach

Depth detectors are designed to search for objects located at impressive depths. They can detect metal at a depth of up to 6 meters, while other models “pierce” only up to 3. Such devices recognize voids and other internal soil anomalies. Depth detectors operate on two coils, one is parallel to the ground surface, the other is perpendicular.

Stationary detectors are frames installed at particularly important protected sites. They detect any metal objects in people's bags and pockets that pass through the circuit.

What types of metal detectors can you make at home with your own hands?

Detectors are divided into 5 main types based on the principle of detecting the desired object.

Let's look at which metal detectors are suitable for making with your own hands at home:

And now more about how to make a simple metal detector with your own hands using the example of the “Pirate” design.

Homemade metal detector “Pirate”: diagram and detailed description of the assembly

If you are just thinking about how to make a homemade metal detector, do not try to take on complex models. Start with a simple but effective "Pirate". The name was invented by the author of the homemade product from a combination of Pi (pulse) and Ra-t (radioscope). The name stuck, and the simple and clear assembly scheme was so loved by users that “Pirate” became one of the most popular homemade products in this area. Currently, there are already 4 modifications of the “Pirate” scheme. The metal detector is simply assembled with your own hands, without using any specific tools.

The only drawback of this device is that the DIY metal detector does not have a scheme for working with metal discrimination. But for a novice treasure hunter this is unimportant.

In addition to the parts required for assembly, you will need a soldering iron, screwdriver, and insulating tape.

Parts for assembling a metal detector

To make the device you will need to purchase:

• ceramic capacitor - 1 nF;
• 2 film capacitors - 100 nF;
• electrolytic capacitors: 10 μF (16 V) – 2 pieces, 2200 μF (16 V) – 1 piece, 1 μF (16 V) – 2 pieces, 220 μF (16 V) – 1 piece;
• resistors - 7 pieces per 1; 1.6; 47; 62; 100; 120; 470 kOhm and 6 pieces for 10, 100, 150, 220, 470, 390 Ohm, 2 pieces for 2 Ohm;
• variable resistors - 3 pieces for 10 and 100 kOhm, 400 Ohm (1W);
• transistors – 3 pieces, VS557, IRF740, VS547;
• 2 diodes 1N148;
• 2 microcircuits: K157UD2 and NE555.

In addition to the listed details, stock up on headphones from the player

You will also need plastic pipe for the rod, 9V batteries or accumulators and PEV wire with a diameter of 0.8 mm.

For your information! Many people are interested in how to make a metal detector from a phone with their own hands. Some developers even offer programs that can be downloaded to your phone and used for this purpose. Serious radio enthusiasts can only advise you to use some spare parts - for example, a headphone input or a battery, perhaps a board to create a microcircuit.

DIY metal detector circuits

The simplest “Pirate” scheme looks like this.

The board can be placed in the body of a pocket receiver or any convenient size plastic box, even simple ones are suitable distribution boxes from an electrician's arsenal.

Important point! To get rid of possible interference when touching the device regulators, all variable resistor housings are connected to the negative side of the board.

If you want to take your experiments further, here is a diagram for making a gold-focused metal detector.

Schematic of the Terminator 4 metal detector with increased sensitivity

If you assembled the circuit correctly, the device will work properly. Possible problems with a microcircuit.

How to assemble a metal detector circuit board with your own hands

The metal detector circuit board circuit is quite simple. Conventionally, it can be divided into several blocks:

• search coil assembly;
• transistor sound amplifier;
• pulse generator;
• two-channel amplifier.

This is what it looks like.

The pulse generator is assembled on the NE555 timer. By selecting C1 and 2 and R2 and 3, the frequency is adjusted. The pulses obtained as a result of scanning are transmitted to transistor T1, and it transmits the signal to transistor T2. The audio frequency is amplified using the BC547 transistor to the collector, and headphones are connected.

For your information! You can make a metal detector with your own hands without microcircuits. On the Internet you will find many analog circuits using transistor oscillators. Such devices will detect metal at a depth of up to 20 centimeters in the ground and up to 30 centimeters in loose sand.

How to make a metal detector coil with your own hands

The coil is an important part of the device. It can be made from copper wire or twisted pair. More details in our master class.

Copper wire spool

Illustration	Description of action
	Copper wire with a diameter of 0.5 mm is suitable for the coil.
	For winding, prepare a board with guides. The distance between the guides should be equal to the diameter of the base on which you will mount the reel.
	Wind the wire around the perimeter of the fastenings in 20-30 turns.
	Secure the winding with electrical tape in several places.
	Remove the winding from the base and give it a round shape.
	Choose a base that will hold its shape. This could be a plastic bucket lid or a wooden craft hoop.
	Connect the circuit to the device and test its operation.
	IN assembled form a coil of wire might look like this.
	To test the operation of the device, pass metal objects over the coil at different heights.

Twisted pair coil

Illustration	Description of action
	Roll the wire into two coils as shown in the photo, leaving two ends of approximately 10 centimeters each.
	Strip the winding and free the wires for connection.
	Connect the wires as shown in the diagram.
	For better contact, solder the ends of the wires.
	Test the coil in the same manner as the copper wire coil.

Advice! If you want to make a more powerful DIY coil for your metal detector, give it an elliptical shape.

Detailed instructions for setting up a DIY metal detector “Pirate”

For final assembly of the device you will need a plastic pipe. The assembly diagram is simple. The sensitivity of the detector is adjusted using potentiometers. Achieve the result so that it recognizes a coin from a distance of 30 centimeters. He can “hear” large metal deposits a meter to one and a half meters away. “Pirate” does not recognize non-ferrous or ferrous metals underneath you, so you just have to dig, and it is possible that you will stumble upon an old trough, and not the desired treasure. But in this case, you can take it not by quality, but by quantity, because any metal can be taken to a recycling collection point.

It is possible that you will be lucky and all your efforts will not be in vain

What the assembled “Pirate” will look like is in the next video. It only remains to note that the construction kit for making this device can be purchased on the Internet. By the way, it comes with detailed instructions on how to make a metal detector yourself at home from kit parts.

Features of deep metal detectors

A deep metal detector is attractive because it can detect objects where other devices are powerless. A good deep metal detector, made with your own hands, looks to a depth of 6 meters, and is not hindered by roots, voids or other obstacles. One caveat - with its help you can only detect large objects, and this is understandable, because for the sake of a couple of coins you will not dig a six-meter hole.

And again we return to the same universal model of the “Pirate” detector. It turns out that a deep-depth device can be made on its basis, and this is not at all difficult. The modification process is described in this video.

Instrumental search is simply enormously popular. Adults and children, amateurs and professionals are looking for it. They are looking for treasures, coins, lost things and buried scrap metal. The main search tool is a metal detector.

There are a great variety of different metal detectors to suit every taste and color. But for many people, buying a ready-made branded metal detector is simply financially expensive. And some people want to assemble a metal detector with their own hands, and some even build their own small business on their assembly.

Homemade metal detectors

In this section of our website about homemade metal detectors, I will collect: best schemes metal detectors, their descriptions, programs and other data for making a metal detector with your own hands. There are no metal detector circuits from the USSR or circuits with two transistors here. Since such metal detectors are only suitable for visually demonstrating the principles of metal detection, but are not at all suitable for real use.

All metal detectors in this section will be quite technologically advanced. They will have good search characteristics. And a well-assembled homemade metal detector is not much inferior to its factory-made counterparts. Mainly presented here various schemes pulse metal detectors and metal detector circuits with metal discrimination.

But to make these metal detectors, you will need not only desire, but also certain skills and abilities. We tried to break down the diagrams of the given metal detectors by level of complexity.

In addition to the basic data required to assemble a metal detector, there will also be information about the required minimum level of knowledge and equipment for making a metal detector yourself.

To assemble a metal detector with your own hands, you will definitely need:

This list will include necessary tools, materials and equipment, for self-assembly all metal detectors without exception. For many circuits you will also need different additional equipment and materials, here are just the basics for all schemes.

1. Soldering iron, solder, tin and other soldering supplies.
2. Screwdrivers, pliers, wire cutters and other tools.
3. Materials and skills for making a printed circuit board.
4. Minimum experience and knowledge in electronics and electrical engineering as well.
5. And also straight hands will be very useful when assembling a metal detector with your own hands.

Here you can find diagrams for self-assembly of the following models of metal detectors:

Design and principle of operation of the device

Metal detectors on the market operate on different principles. Many believe that they use the principle of pulse echo or radar. Their difference from locators lies in the fact that the transmitted and received signals act constantly and simultaneously; in addition, they operate at the same frequencies.

The principle of operation of the metal detector

Devices operating on the “receive-transmit” principle record the signal reflected (re-emitted) from a metal object. This signal appears due to the influence of variables on a metal object. magnetic field, which is generated by the metal detector coils. That is, the design of devices of this type provides for the presence of two coils, the first is transmitting, the second is receiving.

Metal detector circuit

Devices of this class have the following advantages:

• simplicity of design;
• Great potential for detecting metallic materials.

At the same time, metal detectors of this class have certain disadvantages:

• metal detectors can be sensitive to the composition of the soil in which they search for metal objects.
• technological difficulties in the production of the product.

In other words, devices of this type must be configured with your own hands before work.

Other devices are sometimes called beat metal detectors. This name comes from the distant past, more precisely from the times when superheterodyne receivers were widely used. Beating is a phenomenon that becomes noticeable when two signals with similar frequencies and equal amplitudes are summed. The beat consists of pulsating the amplitude of the summed signal.

The signal pulsation frequency is equal to the difference in the frequencies of the summed signals. By passing such a signal through a rectifier, it is also called a detector, and the so-called difference frequency is isolated.

This scheme has been used for a long time, but nowadays it is not used. They were replaced by synchronous detectors, but the term remained in use.

A beat metal detector works using next principle– it registers the frequency difference from two generator coils. One frequency is stable, the second contains an inductor.

The device is configured with your own hands so that the generated frequencies match or at least are close. As soon as metal enters the action zone, the set parameters change and the frequency changes. Frequency difference can be recorded in different ways, ranging from headphones to digital methods.

Devices of this class are characterized by a simple sensor design and low sensitivity to the mineral composition of the soil.

But besides this, when using them, it is necessary to take into account the fact that they have high energy consumption.

Typical design

The metal detector includes the following components:

1. The coil is a box-type structure that houses the signal receiver and transmitter. Most often, the coil has an elliptical shape and polymers are used for its manufacture. A wire is connected to it connecting it to the control unit. This wire transmits the signal from the receiver to the control unit. The transmitter generates a signal when metal is detected, which is transmitted to the receiver. The coil is installed on the lower rod.
2. The metal part on which the reel is fixed and its angle of inclination is adjusted is called the lower rod. Thanks to this solution, a more thorough examination of the surface occurs. There are models in which the lower part can adjust the height of the metal detector and provides a telescopic connection to the rod, which is called the middle one.
3. The middle rod is the unit located between the lower and upper rods. Devices are attached to it that allow you to adjust the size of the device. On the market you can find models that consist of two rods.
4. The top rod usually has a curved appearance. It resembles the letter S. This shape is considered optimal for attaching it to the hand. An armrest, a control unit and a handle are installed on it. The armrest and handle are made of polymer materials.
5. The metal detector control unit is necessary to process the data received from the coil. After the signal is converted, it is sent to headphones or other display devices. In addition, the control unit is designed to regulate the operating mode of the device. The wire from the coil is connected using a quick release device.

Metal detector design

All devices included in the metal detector are waterproof.

It is this relative simplicity of design that allows you to make metal detectors with your own hands.

Types of metal detectors

There is a wide range of metal detectors on the market, used in many areas. Below is a list showing some of the varieties of these devices:

Ground model Deep metal detector Underwater vehicle Security device Industrial metal detector

1. Ground. These devices are designed for DIY searches for scrap metal, jewelry, coins, etc.
2. Deep. These devices are used to search for the above-mentioned metal products at great depths.
3. Underwater. Devices of this type are designed to operate underwater. They can work at different depths.
4. Metal detectors for searching for gold. These devices allow you to find gold and gold jewelry in any environment.
5. Security devices. These devices are used to detect metal products on the human body and in luggage. Such devices are made in the form of arches and are installed at the entrance to places large cluster people, for example, at train stations, shopping centers, etc.
6. Industrial. This equipment is part of conveyor lines. Their main task is to detect metal in other substances. For example, in a mined sand-soil mixture.
7. Army. The military uses such devices to detect mines, unexploded shells, bombs, etc. with their own hands. The military calls such devices mine detectors.
8. Do-it-yourself devices are most often assembled by novice “treasure hunters”.

Usage modern materials allows you to design and manufacture devices with high precision metal detection in different environments. The use of microelectronics has made it possible to minimize their overall weight parameters. In addition, simplicity electrical diagram allows with minimal costs make a metal detector with your own hands.

Basic parameters

Like any technical device, a metal detector has certain parameters that characterize its functional properties.

Detection depth

In the first place is the depth of metal detection. By the way, many companies producing such devices do not indicate the maximum depth at which their products can detect metal products. And if such a figure is indicated, then most likely this is data obtained during laboratory tests. That is, real field conditions differ significantly from laboratory (test) ones.

This means that when doing real work with your own hands, the detection depth will be slightly less than indicated in the passport. Why is this happening? The fact is that the composition of the soil has a significant impact on the capabilities of the metal detector. Indeed, it is one thing to search in river sand, and the other in soil with a high iron content. Hardware, especially those that long time are located at depth, oxidize and change their properties, and this affects the ability to detect the object.

Metal detector detection depth

Most modern metal detectors can find metal objects at a depth of up to 2.5 m; special depth products can detect a product at a depth of up to 6 meters.

Operating frequency

The second parameter is the operating frequency. The thing is that low frequencies allow the metal detector to see to a fairly large depth, but they are not able to see small details. High frequencies allow you to notice small objects, but do not allow you to view the ground to great depths.

The simplest (budget) models operate at one frequency; models that fall into the middle price range use 2 or more frequencies. There are models that use 28 frequencies when searching.

Diagram of a deep metal detector

Deep metal detectors are used to search for metals at great depths. But it is worth noting that they are not cheap and therefore it is quite possible to assemble it yourself. But before you start making it, you need to understand how a typical circuit works.

Diagram of a deep metal detector

The circuit of a deep metal detector is not the simplest and there are several options for its implementation. Before assembling it, you need to prepare the following set of parts and elements:

• capacitors different types– film, ceramic, etc.;
• resistors of different values;
• semiconductors - transistors and diodes.

Nominal parameters and quantity depend on the selected circuit diagram of the device. To assemble the above elements, you will need a soldering iron, a set of tools (screwdriver, pliers, wire cutters, etc.), and material for making the board.

Assembly process of a deep metal detector

The process of assembling a deep metal detector looks something like this. First, a control unit is assembled, the basis of which is a printed circuit board. It is made from textolite. Then the assembly diagram is transferred directly to the surface of the finished board. After the drawing is transferred, the board must be etched. To do this, use a solution that includes hydrogen peroxide, salt, and electrolyte.

After the board is etched, it is necessary to make holes in it to install the circuit components. After tinning the board. The most important stage is coming. Do-it-yourself installation and soldering of parts onto a prepared board.

To wind the coil with your own hands, use PEV brand wire with a diameter of 0.5 mm. The number of turns and the diameter of the coil depend on the selected circuit of the deep metal detector.

As an example, let's look at the most common metal detectors that can work with deep frames - Koschey,. If you follow the suggested diagrams, creating a deep metal detector with your own hands will not be difficult.
The first stage will be the manufacture and configuration of the electronic unit. At the next stage, you will need to build a deep coil. In the material below we will examine in detail existing methods creating coils for deep metal detectors with your own hands.
It is important to take into account the size and weight of structures. For example, if we take the Pirate, the indicators will be quite modest, and the highest result will be when using units such as Koschey 5IG or Koschey 4IG. Such results are obtained due to the presence of a separate deep firmware in the latter.

DIY depth frame for a metal detector

The most common practice is to install small depth frames directly on a rod or a standard reel. In this case, there are some restrictions on weight and size parameters. For this reason, this design is suitable only for those frames that have a diameter of up to sixty centimeters. A product with a larger diameter will be too heavy, so it will be quite uncomfortable to carry.
You can produce the frame for the reel using ordinary pipes made of plastic. The pipe should be selected depending on the method by which you plan to connect it. Also, when choosing a pipe, you need to take into account the dimensions of your frame, since it is important that the pipe can provide maximum rigidity to the overall structure.

Depth coil design shape

Reels that have small in size, it is best to make them non-separable and shaped like a circle or square. When creating frames with large dimensions, a non-dismountable design will be inconvenient during transportation. It is quite difficult to move a frame of this type from place to place. Therefore, in this case it is better to make a collapsible type structure. It is better to build a structure with a collapsible frame in the shape of a square, which is equipped with an overhead search loop. Therefore, the frame frame should be made only from pipes that are made of durable plastic. Search coil will need to be wrapped using insulating stranded wire. Most often, frames of this type are carried in pairs. There is also the option of creating a structure that you can move yourself.
A few photos as an example:

Depth frame winding process

In order to wind frames, it is best to use stranded wire in insulation, which has a diameter of approximately 0.5-0.75 mm. At the end of the work, you need to tighten the coils tightly enough together using standard electrical tape or adhesive tape. This will make the loop much stronger. After this, to achieve maximum structural strength, it is necessary to compress it with a heat-shrink tube or secure it with electrical tape.
Using the detailed instructions provided, you can build a deep metal detector with your own hands quite easily. To do this, you will need elements that every radio amateur must have in stock. A device created with your own hands will not be inferior in functionality to its factory counterparts, and it will cost you an order of magnitude cheaper.