Go ahead and search for treasure! How to make a powerful metal detector at home with your own hands. DIY underwater metal detector DIY underwater metal detector
Many people make equipment with their own hands - this way it costs less than if it were bought in a store. Is it possible to assemble an underwater metal detector with your own hands? Every beginner and professional search engine has this opportunity. It should immediately be noted that the assembly process will require experience in assembling electronic circuits and knowledge in the field of electronics. Without all this, attempts to assemble a full-fledged underwater metal detector with your own hands will be unsuccessful.
What is needed to assemble a metal detector? First you need to find a suitable scheme. It should provide the possibility of underwater search in salt and fresh water, and to the maximum possible depth. Many schemes allow you to find a five-kopeck coin of the USSR in the ground at a depth of 20-25 cm. The depth of immersion depends on your ability to create sealed enclosures. In total we need to do the following things:
- Find a suitable scheme;
- Purchase parts;
- Draw up a diagram of the layout of elements on a printed circuit board;
- Create a printed circuit board and place all the circuit elements on it.
Pay attention to the quality of soldering - it must be high so that the metal detector can operate without failures. You can fill the board with epoxy resin to provide protection from water, but this can make it difficult to replace parts if the metal detector breaks down.
When creating an underwater metal detector with your own hands, you will need to create a search coil. On the Internet you will find many options for coils, and you can ensure their tightness using any plastic material, for example, by covering the coil in the same epoxy resin and waiting for it to dry completely. The result is a sealed search coil that can be used to search at a wide range of depths.
At the last stage you need to come up with a body. It must be sealed and not allow water to pass through even at great depths. If the circuit you choose has any controls, you need to ensure that they are sealed and can operate in water. We also ensure the tightness of the battery compartment and connectors for connecting the search coil and headphones.
When assembling an underwater metal detector with your own hands, you may encounter various difficulties:
- The circuit works successfully in air, but begins to act weird under water;
- Setting up the circuit requires the use of an expensive oscilloscope;
- The resulting metal detector is not sensitive;
- There is no place to get waterproof items or underwater headphones.
All these problems can be avoided if you purchase a ready-made underwater metal detector. Factory-assembled devices are distinguished by stable operation in the most difficult conditions and high sensitivity, and underwater headphones are already supplied with them. Ready-made metal detectors from leading brands allow you to find even the smallest metal particles in the ground, and some models can withstand immersion to depths of up to 60 meters. They easily tolerate prolonged exposure to water, notable for their tightness. Well, more advanced search coils will provide a decent search depth. If you have experience in assembling electronic circuits and are well versed in electronics, try assembling an underwater metal detector with your own hands - homemade devices, well configured and adjusted, often give brilliant results. Well, their most important advantage is their affordable cost, which compares favorably with the cost of factory-assembled metal detectors.
It is known that in the seas and lakes - especially in the coastal zone, where there are many vacationers, you can find a lot of gold and silver jewelry. But to search in water, the metal detector coil must be sealed, and the circuit must have its own characteristics - underwater specialization, so to speak. The Underwater P.I homemade underwater metal detector is designed for these purposes, the assembly and configuration of which does not present any particular difficulties. The test parameters turned out to be the following: 5 kopecks of the USSR is about 23-25 cm, large objects are about a meter, maybe a little more (also depends on the position of the DELAY regulator). I checked the device at home.
At the moment I have almost completed the structure for the Surfmaster P.I. (the armrest remains). I soldered on the signet surf rev1.2 (from АpBerg), it can be used. Pay in bark. file is correct, the circuit works immediately after assembly - only the zero at the output of the NE5534 chip needs to be adjusted. What I liked about the metal detector was its sensitivity to small objects (pellets, a small gold earring of complex shape, a pin), the ability to use the DELAY knob to cut off small metal debris made of ferrous metal (nails or long-shaped objects made of black metal give a double peak-peak).
Disadvantages - the inability to ignore various plugs and large iron objects. I wound the coil for the Underwater P.I underwater detector on a three-liter jar. It contains 25-30 turns of 0.5 mm wire. A sketch of the coil is shown below.
In the absence of an IRF9640 field-effect transistor, I installed an IRF9630. Regarding this replacement (and the coil), I selected a reference resistance - installed a variable and tried it by range, since I don’t have an oscilloscope. It turned out to be 600 ohms. When I make the next copy of the submariner, I will try to find the right components and complete the setup more carefully. I installed a button on the pinpointer (it should be Push-off), but I didn’t have to install it. The device is dynamic, so it quite accurately determines the center of the target. The board is interesting, long, and fits well into a silicone glue tube.
With the onset of spring, more and more often you can see people with metal detectors on the banks of rivers. Most of them are engaged in “gold mining” purely out of curiosity and passion. But a certain percentage actually earn a lot of money from searching for rare things. The secret to the success of such research is not only in experience, information and intuition, but also in the quality of the equipment with which they are equipped. A professional instrument is expensive, and if you have a basic knowledge of radio mechanics, you have probably thought more than once about how to make a metal detector with your own hands. The editors of the site will come to your aid and tell you today how to assemble the device yourself using diagrams.
Read in the article:
Metal detector and its structure
This model costs more than 32,000 rubles, and, of course, non-professionals will not be able to afford such a device. Therefore, we suggest studying the design of a metal detector in order to assemble a variation of such a device yourself. So, the simplest metal detector consists of the following elements.
The operating principle of such metal detectors is based on the transmission and reception of electromagnetic waves. The main elements of a device of this type are two coils: one is transmitting, and the second is receiving.
The metal detector works like this: the magnetic field lines of the primary field (A) of red color pass through the metal object (B) and create a secondary field (green lines) in it. This secondary field is picked up by the receiver and the detector sends an audible signal to the operator. Based on the principle of operation of emitters, electronic devices of this type can be divided into:
- Simple, working on the “receive-transmit” principle.
- Induction.
- Pulse.
- Generating.
The cheapest devices belong to the first type.
An induction metal detector has one coil that sends and receives a signal simultaneously. But devices with pulse induction differ in that they generate a transmitter current, which turns on for a while and then turns off abruptly. The coil field generates pulsed eddy currents in the object, which are detected by analyzing the attenuation of the pulse induced in the receiver coil. This cycle repeats continuously, perhaps hundreds of thousands of times per second.
How does a metal detector work depending on its purpose and technical device?
The operating principle of a metal detector varies depending on the type of device. Let's consider the main ones:
- Dynamic type devices. The simplest type of device that continuously scans the field. The main feature of working with such a device is that you must be in motion all the time, otherwise the signal will disappear. Such devices are easy to use, however, they are poorly sensitive.
- Pulse type devices. They have great sensitivity. Often, such a device comes with several additional coils for adjustment to different types of soils and metals. Requires certain skills to set up. Among the devices of this class we can distinguish electronic devices operating at low frequencies - no higher than 3 kHz.
- Electronic devices, on the one hand, do not give a reaction (or give a weak one) to unwanted signals: wet sand, small pieces of metal, shot, for example, and, on the other hand, they provide good sensitivity when searching for hidden water pipes and central heating routes, as well as coins and other metal objects.
- Depth detectors designed to search for objects located at impressive depths. They can detect metal objects at a depth of up to 6 meters, while other models “pierce” only up to 3. For example, the Jeohunter 3D depth detector is capable of searching and detecting voids and metals, while showing objects found in the ground in 3- measured form.
Depth detectors operate on two coils, one is parallel to the ground surface, the other is perpendicular.
- Stationary detectors- these are frames established at particularly important protected sites. They detect any metal objects in people's bags and pockets that pass through the circuit.
Which metal detectors are suitable for making yourself at home?
The simplest devices that you can assemble yourself include devices that operate on the principle of reception and transmission. There are schemes that even a novice radio amateur can do; for this you just need to select a certain set of parts.
There are many video instructions on the Internet with detailed explanations of how to make a simple metal detector with your own hands. Here are the most popular ones:
- Metal detector "Pirate".
- Metal detector - butterfly.
- Emitter without microcircuits (IC).
- Series of metal detectors "Terminator".
However, despite the fact that some entertainers are trying to offer systems for assembling a metal detector from a phone, such designs will not pass the battle test. It’s easier to buy a children’s metal detector toy, it will be more useful.
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
Homemade products based on the “Pirate” series metal detector are among the most popular among radio amateurs. Thanks to the good performance of the device, it can “detect” an object at a depth of 200 mm (for small items) and 1500 mm (large items).
Parts for assembling a metal detector
The Pirate metal detector is a pulse type device. To make the device you will need to purchase:
- Materials for making the body, rod (you can use a plastic pipe), holder, and so on.
- Wires and electrical tape.
- Headphones (suitable for the player).
- Transistors – 3 pieces: BC557, IRF740, BC547.
- Microcircuits: K157UD2 and NE
- 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.
- 2 diodes 1N148.
DIY metal detector circuits
The classic circuit of the “Pirate” series metal detector is built using the NE555 microcircuit. The operation of the device depends on a comparator, one output of which is connected to the IC pulse generator, the second to the coil, and the output to the speaker. If metal objects are detected, the signal from the coil is sent to the comparator, and then to the speaker, which notifies the operator of the presence of the desired objects.
The board can be placed in a simple junction box, which can be purchased at an electrical store. If such a tool is not enough for you, you can try to make a more advanced device; a diagram for making a gold-oriented metal detector will help you.
How to assemble a metal detector without using microcircuits
This device uses Soviet-style transistors KT-361 and KT-315 to generate signals (you can use similar radio components).
How to assemble a metal detector circuit board with your own hands
The pulse generator is assembled on the NE555 chip. 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.
To place radio components, a printed circuit is used, which can be easily made independently. To do this, we use a piece of sheet getinax covered with copper electrical foil. We transfer the connecting parts onto it, mark the fastening points, and drill holes. We cover the tracks with a protective varnish, and after drying, we lower the future board into ferric chloride for etching. This is necessary to remove unprotected areas of copper foil.
How to make a metal detector coil with your own hands
For the base you will need a ring with a diameter of about 200 mm (ordinary wooden hoops can be used as the base), on which 0.5 mm wire is wound. To increase the depth of metal detection, the coil frame should be in the range of 260−270 mm, and the number of turns should be 21−22 vol. If you don't have anything suitable on hand, you can wind a reel on a wooden base.
Copper wire spool on wooden base
| Illustration | Description of action |
 | For winding, prepare a board with guides. The distance between them is equal to the diameter of the base on which you will attach 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 rounded shape; if necessary, additionally fasten the winding in several more places. |
 | Connect the circuit to the device and test its operation. |
Twisted pair coil in 5 minutes
We will need: 1 twisted pair 5 cat 24 AVG (2.5 mm), knife, soldering iron, solder and multitester.
| Illustration | Description of action |
 | Twist the wire into two skeins. Leave 10 cm on each side. |
 | Strip the winding and free the wires for connection. |
 | We connect the wires according to the diagram. |
 | For better fastening, solder them with a soldering iron. |
 | Test the coil in the same manner as the copper wire device. The winding terminals must be soldered to a stranded wire with a diameter in the range of 0.5-0.7 mm. |
Brief instructions for setting up a DIY metal detector “Pirate”
Once the main elements of the metal detector are ready, we proceed to assembly. We attach all the components to the metal detector rod: the body with the coil, the receiving and transmitting unit and the handle. If you did everything correctly, then additional manipulations with the device will not be required, since it initially has maximum sensitivity. Fine tuning is performed using variable resistor R13. Normal operation of the detector should be ensured with the regulator in the middle position. If you have an oscilloscope, then use it to measure the frequency at the gate of transistor T2, which should be 120−150 Hz, and the pulse duration should be 130−150 μs.
Is it possible to make an underwater metal detector with your own hands?
The principle of assembling an underwater metal detector is no different from a conventional one, with the only difference being that you will have to work hard to create an impenetrable shell using sealant, as well as to place special light indicators that can report a find from under water. An example of how this will work is in the video:
Do-it-yourself metal detector “Terminator 3”: detailed diagram and video instructions for assembly
The Terminator 3 metal detector has occupied an honorable place among homemade metal detectors for many years. The two-tone device operates on the principle of induction balance.
Its main features are: low power consumption, metal discrimination, non-ferrous metals mode, gold only mode and very good search depth characteristics, compared to semi-professional branded metal detectors. We offer you the most detailed description of the assembly of such a device from folk craftsman Viktor Goncharov.
How to make a metal detector with your own hands with metal discrimination
Metal discrimination is the ability of the device to distinguish between the detected material and classify it. Discrimination is based on different electrical conductivities of metals. The simplest methods for determining the types of metals were implemented in old instruments and entry-level devices and had two modes - “all metals” and “non-ferrous”. The discrimination function allows the operator to respond to a phase shift of a certain magnitude, compared to a configured (reference) level. In this case, the device cannot distinguish between non-ferrous metals.
Learn how to make a homemade professional metal detector using improvised materials in this video:
Features of deep metal detectors
Metal detectors of this type can detect objects at great depths. A good metal detector, made by yourself, looks to a depth of 6 meters. However, in this case the size of the find must be substantial. These detectors work best for detecting old shells or large enough debris.
There are two types of deep metal detectors: frame and transceiver on a rod. The first type of device is capable of covering a large area of land for scanning, however, in this case, the efficiency and focus of the search is reduced. The second version of the detector is a point detector; it works directed inward over a small diameter. You need to work with it slowly and carefully. If your goal is to build such a metal detector, the following video can tell you how to do it.
If you have experience in assembling such a device and using it, tell others about it!
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. And the main search tool is 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 be collected: best metal detector circuits, their descriptions, programs and other data for manufacturing DIY metal detector. 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. Basically, there are various schemes presented here 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 contain the necessary tools, materials and equipment for self-assembly of all metal detectors without exception. For many schemes you will also need various additional equipment and materials, here are just the basics for all schemes.
- Soldering iron, solder, tin and other soldering supplies.
- Screwdrivers, pliers, wire cutters and other tools.
- Materials and skills for making a printed circuit board.
- Minimum experience and knowledge in electronics and electrical engineering as well.
- 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:
 |
Principle of operation | I.B. |
| Metal discrimination | There is | |
| Maximum search depth | ||
| There is | ||
| Operating frequency | 4 - 17 kHz | |
| Difficulty level | Average | |
 |
Principle of operation | I.B. |
| Metal discrimination | There is | |
| Maximum search depth | 1-1.5 meters (Depends on the size of the coil) | |
| Programmable microcontrollers | There is | |
| Operating frequency | 4 - 16 kHz | |
| Difficulty level | Average | |
 |
Principle of operation | I.B. |
| Metal discrimination | There is | |
| Maximum search depth | 1 - 2 meters (Depends on the size of the coil) | |
| Programmable microcontrollers | There is | |
| Operating frequency | 4.5 - 19.5 kHz | |
| Difficulty level | High | |
Radio amateurs are not those who want to save money and not purchase new equipment, but those who want to maximize all the existing parameters of a particular device. This statement also applies to those who are going to assemble metal detectors with their own hands. If a person has certain knowledge in the design of technology, they should be used to the fullest. This is much better than buying ready-made equipment for a lot of money at a time when the filling in it costs less than a third of the total amount. Based on the above, if you are one of the radio amateurs and are planning to assemble an underwater metal detector with your own hands, then we will help you do it right now.
What are the main differences between an underwater metal detector?
An underwater metal detector is a special device that is designed to detect metal objects not only on the surface, but also in the water column. Thanks to such equipment, you have the opportunity to search for objects made of metals and alloys in the presence of poor visibility and strong noise.
The main difference between an underwater vehicle and a conventional detector is that the former has the ability to remain under water for a long period. When developing this equipment, one should take into account the fact that many search engines go almost up to their necks in water, so the depth of immersion is also of great importance. Such metal detectors can easily recognize fairly small objects such as earrings, chains and rings. After all, it’s them that underwater search engines are hunting for. When assembling equipment yourself, you can configure it to search mainly for non-ferrous metals. The above differences between an underwater metal detector and a standard ground detector should be taken into account during assembly.
What is needed to assemble an underwater metal detector?
In order to assemble a search coil that will have a diameter of 23 centimeters, you will need a PETV wire, the thickness of which is half a millimeter. You should have approximately 25 turns. Feel free to experiment with the wire and coil shape. For standard equipment approximately 20 meters should be used.
In order to make the rod and control unit, it is better to use plastic or stainless steel tubes. This is important because other metals tend to corrode when working underwater. Thanks to the use of plastic and stainless metal, you can significantly extend the service life of all equipment.
The frame should not be made too light so that the product does not float to the top, but also not too heavy, since otherwise it will sink to the bottom due to its heavy weight. Here it is best to take a closer look at your own feelings. The main task when choosing a material for the production of a rod is that it must be highly resistant to use in sea water and not be destroyed due to frequent exposure to an aggressive environment.
As an example, let's consider the construction of an underwater metal detector based on the Surfmaster PI 1.2 metal detector, which works great in both sea and fresh water, has excellent sensitivity for small objects made of non-ferrous metal and board sizes that allow it to be installed in a plastic pipe or tube from under the sealant.
In order to assemble the Surfmaster PI 1.2 underwater metal detector with your own hands, you will need the following tools:
soldering iron;
·PETV wires 0.5 mm;
·insulating tape;
· silicone sealant;
· scissors and knife and some others.
· printed circuit board
· set of electronic components
DIY underwater metal detector Surfmaster P.I diagram
Surfmaster 1.2 Parts List
External view of the Surfmaster 1.2 circuit board
The Surfmaster assembly kit can be purchased at
Assembly steps
Assemble an underwater metal detector with your own hands
can be done in several stages:
·
At the first stage, the most difficult task lies in the manufacture of the printed circuit board.
·
Next, all prepared electronic elements are installed on the board. Soldering should be done in full accordance with the diagram.
·
Connect the power source. Ideally, you should use a powerful battery that can be recharged while you work, rather than regular batteries.
·
Mount the finished board and battery in a small container that is hermetically sealed. It is necessary to bring the variable resistances out of this container, and all the resulting joints and cracks must be fixed with silicone sealant. The already prepared container must be installed on a pre-assembled rod.
·
The coil should be wound. For these purposes, a regular jar with a volume of three liters is suitable. For the reel, you need to choose a housing that is made of plastic material that is not susceptible to water.
·
The leads from the coil must be connected to a stranded wire.
Next, special attention should be paid to the issue of tightness, for which:
·
all cracks formed must be filled with silicone sealant;
·
it is better to use the most standard pipes, which are made of polypropylene, and the diameter can be chosen according to your preferences.
·
To produce a rod, you can use an old fishing rod and ordinary adapters for plastic pipes.
·
The tube left over from the sealant is perfect for assembling the control unit housing.
·
Waterproof ports should be installed on all existing connectors.
