Metal detectors from the perspective of an experienced radio amateur
A few months ago, in the usual conversation with my nephew, the conversation went about metal detectors, treasure hunters, and other similar things. As a radio amateur with experience, I was very much affected by, at first glance, a very profitable idea, not new for a long time, but still very relevant. Therefore he promised to sort out this issue in more detail.
Began to "dig" first on the Internet. It turned out that there is a mass of organizations of treasure hunters, a whole world has been created that thousands of people live in. Everything is complicated and simple at the same time. If you know what you want, you can immediately decide who you are with - professionals or amateurs.
I was interested in the purely technical side of things. The complexity of the equipment, the cost and the possibility of self-production. A lot of reviews and analyzes posted on the sites gave a detailed picture, which I tried to summarize and put at your discretion, with the expectation that many can learn from the information received some benefit.
I would like to start, of course, with the professionals. Serious firms such as Fisher or Garrett produce quite a wide range of metal detectors (or metal detectors) prices usually range from 40 thousand rubles, as, for example, for the Minelab Eureka Gold detector to search for gold nuggets.
Up to 8 thousand rubles for the simpler model of the company Garrett - ACE 150
')
There are significant differences between different models in terms of basic capabilities; for the more expensive models, this list is huge, I provide basic data:
In the "All Metals" mode, you can detect objects at a considerable depth.
Determining the type of metal on the difference of sound.
Special sound signal from the coins.
High-level microprocessor control.
You can configure the discriminator for a specific type of metal.
Iron, silver and gold can be determined on the graphic scale.
It is possible to measure the size of the object, the depth of its location with simultaneous accurate indication of the location on the display screen.
Adjusting the soil balance, both manual and automatic.
Voice message about the characteristics of the last detected target.
I will not complement the availability of various accessories and connectors - this is understandable by itself. It is interesting that for your money you can buy a device of any configuration, add a depth magnifier to the model, for example, TreasureHound EagleEye for the GTI 2500 ,
allowing to significantly increase the depth of search.
Reviews are quite interesting, but confusing price of the goods. In order to buy it, you need to have considerable experience in treasure hunting, because I considered the option of self-production.
In the short review I will not describe the theoretical aspects of the electrical processes in the circuits widely ; I will try to simplify the theory for a better understanding of a wide range of readers.
It is known from physics that metals have a certain electrical and magnetic permeability, that is, when a metal is placed inside an electric coil, its inductance changes - if the metals are magnetic, like iron, the inductance increases, if you take brass - the inductance decreases. On this physical dependence built most of the simplest schemes of metal detectors.
I tried it practically - the scheme works, it detects metal objects, but, alas, a lot of flaws: low sensitivity, it is not possible to accurately determine the type of metal, the work is unstable, although large pieces of iron can be successfully detected at a depth of up to a meter.
The second physical principle is the reflection of an electrical signal from metallic surfaces. Simplified operation of TR / VLF type devices : the transmitter emits a signal with a frequency of usually from tens to hundreds of kilohertz, the receiver receives a reflected one.
The return signal is determined by the presence of metal and the distance to it. Advantages - more accurate metal search, greater sensitivity, better circuit stability. Disadvantages - complex circuitry, the problem with the manual manufacture of high-quality working coil, the complexity of setting up the circuit to the required quality of work.
After checking and reading I came to the same conclusion as many other lovers:
For fun or when searching for metals in a particular place for personal purposes, not for profit or sports interest, it is enough to make a simple scheme and with its help to look for large pieces of iron lying in the ground since the Second World War or scrap metal, buried by an excavator from the collective farm of the Soviet Union . The cost of such a scheme will be within a few hundred rubles.
If you want to engage in metal mining on a large scale and, hoping to have either gain or exciting adventures, it is better, of course, to purchase a good instrument from a normal company. In this case, you will discover a completely new mysterious world, where you can discover many underground secrets and take part in various expeditions. The price of such pleasure is from 8 to 40 thousand rubles .
Well, did not have the desire to try the taste of adventure?
Began to "dig" first on the Internet. It turned out that there is a mass of organizations of treasure hunters, a whole world has been created that thousands of people live in. Everything is complicated and simple at the same time. If you know what you want, you can immediately decide who you are with - professionals or amateurs.
I was interested in the purely technical side of things. The complexity of the equipment, the cost and the possibility of self-production. A lot of reviews and analyzes posted on the sites gave a detailed picture, which I tried to summarize and put at your discretion, with the expectation that many can learn from the information received some benefit.
I would like to start, of course, with the professionals. Serious firms such as Fisher or Garrett produce quite a wide range of metal detectors (or metal detectors) prices usually range from 40 thousand rubles, as, for example, for the Minelab Eureka Gold detector to search for gold nuggets.
Up to 8 thousand rubles for the simpler model of the company Garrett - ACE 150
')
There are significant differences between different models in terms of basic capabilities; for the more expensive models, this list is huge, I provide basic data:
In the "All Metals" mode, you can detect objects at a considerable depth.
Determining the type of metal on the difference of sound.
Special sound signal from the coins.
High-level microprocessor control.
You can configure the discriminator for a specific type of metal.
Iron, silver and gold can be determined on the graphic scale.
It is possible to measure the size of the object, the depth of its location with simultaneous accurate indication of the location on the display screen.
Adjusting the soil balance, both manual and automatic.
Voice message about the characteristics of the last detected target.
I will not complement the availability of various accessories and connectors - this is understandable by itself. It is interesting that for your money you can buy a device of any configuration, add a depth magnifier to the model, for example, TreasureHound EagleEye for the GTI 2500 ,
allowing to significantly increase the depth of search.
Reviews are quite interesting, but confusing price of the goods. In order to buy it, you need to have considerable experience in treasure hunting, because I considered the option of self-production.
In the short review I will not describe the theoretical aspects of the electrical processes in the circuits widely ; I will try to simplify the theory for a better understanding of a wide range of readers.
It is known from physics that metals have a certain electrical and magnetic permeability, that is, when a metal is placed inside an electric coil, its inductance changes - if the metals are magnetic, like iron, the inductance increases, if you take brass - the inductance decreases. On this physical dependence built most of the simplest schemes of metal detectors.
I tried it practically - the scheme works, it detects metal objects, but, alas, a lot of flaws: low sensitivity, it is not possible to accurately determine the type of metal, the work is unstable, although large pieces of iron can be successfully detected at a depth of up to a meter.
The second physical principle is the reflection of an electrical signal from metallic surfaces. Simplified operation of TR / VLF type devices : the transmitter emits a signal with a frequency of usually from tens to hundreds of kilohertz, the receiver receives a reflected one.
The return signal is determined by the presence of metal and the distance to it. Advantages - more accurate metal search, greater sensitivity, better circuit stability. Disadvantages - complex circuitry, the problem with the manual manufacture of high-quality working coil, the complexity of setting up the circuit to the required quality of work.
After checking and reading I came to the same conclusion as many other lovers:
For fun or when searching for metals in a particular place for personal purposes, not for profit or sports interest, it is enough to make a simple scheme and with its help to look for large pieces of iron lying in the ground since the Second World War or scrap metal, buried by an excavator from the collective farm of the Soviet Union . The cost of such a scheme will be within a few hundred rubles.
If you want to engage in metal mining on a large scale and, hoping to have either gain or exciting adventures, it is better, of course, to purchase a good instrument from a normal company. In this case, you will discover a completely new mysterious world, where you can discover many underground secrets and take part in various expeditions. The price of such pleasure is from 8 to 40 thousand rubles .
Well, did not have the desire to try the taste of adventure?
Source: https://habr.com/ru/post/87982/
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