How to choose a metal detector

• Non-LCD detectors that either use no digital signal processing or only to a limited extent that does not affect the audio response of the detector.

More detailed explanation

Today, only a few reputable companies are engaged in the production of analog detectors for beginners. The detectors are equipped only spartanly. They usually have settings for sensitivity, discrimination and volume, which could lead to detectors at a lower design and technical level. But that is not true! The production of such a detector is more expensive, mainly due to the comparison with increasingly cheaper digital technologies.

The construction of analog detectors is very precise, it is the only way, because you can't help yourself with a digital trick here. Discriminant circuits of much more expensive models are often used and differ only in the minimum number of functions. But as with all other detectors, it is necessary to stick to their actual performance. If the finder - beginner can do without the answer on the LCD, it is always a good choice, it will bring him the right habits when searching.

3. Professional digital detectors

Quick reply:

• Digital detectors with graphical response to LCD, controlled by fast processors. The detectors are characterized by a relatively accurate graphical response, great variability of settings and the ability to work on multiple frequencies.

More detailed explanation:

The selection is currently huge and basically all reputable manufacturers produce some top "digital". Regardless of the price, the differences in the performance of individual models are often significantly larger than might be expected.

As with all detectors, you should monitor the instrument's performance, evaluation accuracy and how it handles soil out-tuning. All other features can make searching more enjoyable or simpler, but they are not critical.

Top detectors use different technologies. The best available technology today is multifrequency FBS2. However, there are a number of other devices that use one or a combination of several individual frequencies and yet belong to the top.

If you want to choose a top device for you, ask experienced people. Never settle for one opinion and try to find tests and reviews for a particular device. For detectors where there is no material available except for the text in the e-shop, there could be a problem. In addition, there is a lot of competition in the class and many sellers often resort to, say, very rude behavior. If someone vehemently tells you that a certain device is definitely not suitable for you, it may be exactly what would suit you best. Find out more about it and contact distributors for the Czech Republic with questions.

And now for a little „detector Latin“

1. No detector will show you the shape of the object under the probe. Thanks to technology and your experience, you will be able to estimate the size and depth of storage with top devices. But you will never know "what it is" for sure before you dig it up.

2. The range of the detector is limited by physical possibilities. If you read somewhere that the detector has a range in meters on a single coin .... it's nonsense! Top detectors in the hands of experienced detectors are able to capture a single coin of size 1 CZK at a depth of up to 40 cm. An object the size of a military canister in about one meter. The theoretically calculated ranges on an infinite metal surface are then around two meters. Unfortunately, smaller targets are much more usual :)

4. Professional analog detectors

Quick reply:

• Top detectors without target resolution on LCD. In most cases, with excellent discrimination, reach, rapid recovery after acceptance of the target and thus top separation properties.

   

More detailed explanation:

Talking about analog detectors is actually quite inaccurate, as all devices today already use a microprocessor. In essence, these are devices without LCD, where digital technology serves primarily to precisely control all the functions of the detector.

High-quality analogues thus provide, above all, a very fast response to the target and, thanks to this, they have exceptional separation abilities. In places with a large amount of waste, it is easier to separate individual objects. Also, the range of many detectors is at the level of the best digital devices, but at a significantly lower price. As everything has its pros and cons, here the limitation is given only by audio discrimination, which in practice means that you evaluate the object only as ferromagnetic or non-ferromagnetic. But this suits many searchers, as they still dig everything out of non-ferrous metals. The devices are still very popular and their accuracy is completely comparable to top digital detectors.

5. Detectors for special use

1. Underwater detectors - can be divided into two categories:

• Devices that can be immersed to a small depth (up to a maximum of three meters). These are mostly top devices from the manufacturers for the most universal use and special detectors for divers. The detectors of the first group can be recommended to any searcher who can afford it, so to speak.

• In contrast, deep immersion detectors are usually used only by professionals. They are unsuitable for classic search on land, mainly due to their shorter construction and unnecessarily large weight.

   

2. Detectors for searching for natural gold

There are many detectors that have the word "Gold" in their name, but they have nothing to do with the search for natural gold. The same applies to cheaper variants of various digital detectors, where the word "Gold" means rather greater sensitivity when looking for classic jewelry. Really high-quality detectors for searching for natural gold start at prices around CZK 20,000 and end well above CZK 100,000. In the conditions of the Czech and Slovak Republics, where there are literally microscopic nuggets, betting on the highest quality device is almost the only way to achieve some success.

Accept

Ve slovníčku detektoráře to znamená přijmutí určitého předmětu, lépe řečeno určité povrchové vodivosti předmětu, v nastavení diskriminace.

Air test

Basic tool for testing the detector. The test object is not stored in the soil, but loosely on the surface. This is only an orientation test; impact in soil and evaluation can change dramatically.

All Metal

This is usually referred to as a regime designed to search for all metal objects without discrimination. In many cases, detectors have the greatest range in this mode. But this is not the rule.

Automatic interference debugging

Function in which the detector itself searches for the least disturbed channel. In addition to the automatic function, many detectors have the option of shifting the operating frequency manually, usually by switching in several steps. In many cases, this will help you avoid unwanted interference or excessive reduction of the detector's sensitivity.

Automatic soil out-tuning

In automatic mode, the detector debugs the influence of minerals and metal ions contained in the soil.

Bag

A commonly used term for a detector bag.

Board

Detector motherboard. Printed circuit board containing detector electronics. 

Target - target response

General designation for a certain answer of a given subject. 

Sensitivity

Sensitivity adjustment is the basic setting option for searching with a metal detector. By setting the sensitivity, you affect both the range of the detector and the stability. It is a mistake to think that a detector set to the maximum will always have the maximum range. In locations with a large amount of minerals and waste, you only get an unstable device, if you do that. The optimal compromise between stability and reach is always sought.

Coil

Coil or probe. The basic part of the detector. Thanks to it, the electronics of the detector evaluates the received signals. They are divided into several types and their processing is usually the manufacturer's top secret. A quality probe is often the heart of the detector. The basic types are divided into concentric and Double D (2D). 

Detection - object detection

General search, focus of a particular subject.

Discrimination

In general, the rejection of certain metal objects, or rather, certain surface conductivity of the object. Proper discrimination is one of the most important parameters of a detector, and the development of discriminant circuits is often associated with many patents and secrecy.

Double D

Search probe type. It may also be referred to as 2D or DD. The winding inside the probe creates the shape of two letters D turned back to back. The probes are characterized by a large area coverage, but sometimes at the expense of separation.

Electromagnetic interference

A common problem that a detector may encounter. Today, space is in many cases supersaturated by transmission at many wavelengths. Damaged or old power lines can also be a problem. It usually transmits on most frequencies simultaneously and is virtually non-tunable. Interferences then cause undesirable instability of the detector.

Electromagnetic field

It is formed in all metal objects which conduct electricity. Its behavior and strength depend on several basic factors. The vast majority of metal detectors are based on this physical principle.

Ferromagnetic rocks

These may be rocks of volcanic origin or rocks containing large amounts of metals. In both cases, they cause problems for conventional VLF detectors. There are several devices on the market that will cope with these problems with greater or lesser success. In most cases, these are various basalt filters, etc.

Frequency

Detector operating frequency. It affects the transmission of electromagnetic fields through the soil and also the proper function of the discriminator. Classic VLF detectors operate at a frequency from 3 kHz to 30 kHz. Other designations for frequency bands are LF 30 to 300 kHz, MF 300 kHz to 3 MHz and HF 3 to 30 MHz. 

Graphic response

A mark used to identify a finding on an LCD detector. This is usually a number or segment that shows the measured surface conductivity of the target below the probe.

Treasure hunters

A slang term which refers to all people using a metal detector. In the Czech Republic, however, the term „hledač (searcher)“ or „mrcasník“ is used far more often, which is a word taken from the Brno slang and refers to slackers. Therefore, a certain part of searchers is quite allergic to this term :). 

Target depth identification

A large part of digital detectors is equipped with some graphical identification of the depth of the object under the probe. These are usually different "coin depths" - determining the depth of the coin. Analog devices suffice with an increase in signal strength due to the distance of the object from the probe.

Signal identification

To identify the signal, we use both the audio response of the detector and, if applicable, the visual response on the LCD. But there is only one way to understand what the detector "tells you" - practice. There are a number of objects that can completely confuse the detector (iron rings, crumbling foils, etc.), then it depends mainly on the experience of each searcher.

Concentric probe

This is called probes with a concentric arrangement of forces. The advantage of these probes is a more precise targeting. The disadvantage is less coverage. For this reason, oval concentric probes have recently been created, which are supposed to solve the problem of less concentric probes. 

LCD display

Liquid crystal display. Most digital detectors use this technology for their graphics functions. 

Mineralization

A frequently discussed topic in all detector forums. Ideally, the detector should be able to handle large amounts of salts and metal ions dissolved in the soil. These elements in the soil are collectively called mineralization.

Non-motion detector

Non-motion detectors are characterized by the fact that you do not have to move the search probe to identify the target in the soil. If you identify an object in the soil, you only need to hold the probe still to get a tonal and graphic answer over the target. However, working with a detector is practically no different from motion detectors. As with motion detectors, with non-motion detectors you proceed through the searched place with slow movements reminiscent of mowing the grass, where the probe gradually covers the searched area.

Neutral soil

Soil with a minimum amount of dissolved mineral salts and metal ions. 

Notch

Window or notch. This is a discriminating feature, where you do not proceed from iron to non-ferrous metals when setting up the detector, but you can remove any conductivity number or segment. Since the resulting conductivity of the object can vary significantly in individual soils, it is better to save with this function, if the detector is equipped with it. This function is most often used for filtering iron and aluminum foils. If the selected level is too high, you can easily miss desired targets, such as small silver coins. 

Debugging the effect of mineralization

Or also "soil debugging". This is a key function for the correct function of the detector in many locations. Simple digital and analog detectors use a fixed value. The resulting stability of the detector in the field displayed depends on the level set by individual manufacturers. Higher-class detectors use various, more or less accurate, automatic or manual functions for soil tuning.

Interference suppression

The purpose is to filter out unwanted manifestations of detector instability that cause electromagnetic interference. Some detectors are equipped with an automatic interference suppression function or have the option to shift the operating frequency. In all cases, however, the basic principle is the same - choose a working "channel" so that the detector is disturbed as little as possible. It should be added to this point that most manufacturers try to reduce or eliminate the effect of interference already in the production of search probes, a number of passive solutions are used.

Iron oxides

Frequent manifestation of soil mineralization. Filtering large amounts of these oxides can often cause problems for detectors. For sites with a high concentration of iron oxides in the soil, special metal detectors or pulse detectors are used. 

Surface conductivity

The ability of an object's surface in an electromagnetic field to create eddy currents. For the purposes of metal detectors and the principles used today, this is a key feature. 

Threshold tone

This is the basic setting of the detector, if the device is equipped with this function. Using it, you get greater sensitivity to small objects and also greater depth range. The threshold tone needs to be set sensitively. Too high a value can hide small objects. The usual setting is on the audibility threshold, then the user hears only a faint background sound. There are also a number of detectors in which the threshold function can be used even in the so-called silent discrimination mode, where you do not hear the characteristic sound of the threshold. However, with a higher setting of this function, you will gain in sensitivity.

Phantom signal

Or, a false signal. This phenomenon can easily occur if the sensitivity or threshold tone is set too high. It may be more difficult for a beginner to distinguish this phenomenon from the classic detector response to a finding under a probe. The procedure for mastering the identification of sounds requires a certain amount of experience. For a beginner, it is generally best to start with a lower level of sensitivity and first learn to identify false signals well.

Pulse detectors

Detectors working on the principle of electromagnetic pulses. Unlike conventional VLF detectors, they do not have problems with soil mineralization and are usually characterized by a greater depth range. But the problem is very bad or no discrimination. Devices that can handle at least the basic discrimination of metals (ferrous - non - ferrous metals) are relatively expensive.

Regime

Or, the operating mode of the detector. It can be used to denote both the preset program from the manufacturer (coin, rellic, etc.) and the basic search technique - All Metal, discriminatory, motion, non-motion. Purely individual settings can be marked in the same way. It can then be referred to as the selected operating mode.

Fast response

Often mentioned parameter in detector evaluation. It is desirable that the response of the detector to the target be as fast as possible. Especially with the set discrimination (iron filtration is usual), the time of the so-called recovery of the detector should be as fast as possible. With slower devices, it can easily happen that detectors simply cannot detect targets which are positioned close to one another. 

Scanning

Terrain search by probe. Always keep in mind that the probe should be as close to the ground as possible and as parallel as possible. When searching, do not rush and try to ensure that the individual loops always overlap the previous movement of the probe by 50%.

Targeting

Precise targeting is an important part of mastering the detector. Avoid digging large holes unnecessarily. Here, detectors that work quickly with the signal and do not delay have a big advantage. The classic method is the so-called cross-targeting, where you focus the signal from two sides and at the intersection of the imaginary cross is the object you are looking for. Another possibility is to target the signal using the pinpoint function, when the detector actually switches to non-discriminatory non-motion mode and the detected signal should be located below the center of the probe.