This issue deserves special consideration, because the author had repeatedly to hear and many times to answer it.
To answer this question, you must understand what goals do you have when searching for and what price you expect to achieve them. Typically, a significant portion of people are unaware that many of the problems of finding treasure and relics dare not by improving the characteristics of the devices for searching, and in other ways.
For example, one friend of the author was doing in your spare time on small trips the cities of Russia. He found interesting from his point of view, the buildings of ancient built and thoroughly researched their attics and cellars. Collected Antiques very successful method used. In a similar way still foraged the search engines and in Moscow, despite the rapidly declining number of buildings, not affected by the reconstruction and repairs.
If speech came about attics and basements, it should also be noted that the metal detector near iron pipes and iron roofs, most likely useless due to the "shielding" small items massive search other metallic objects, greatly hindering the search.
Many Muscovites, walking through the Park on the island of the Moscow river in the district Nagatino, and do not suspect that in addition to radioactive ash CHP, at their feet lie a thousand tons of ground excavated by the dredge with the deepening of the waters of the Bay.
Now, in the 70 years from this soil every day after work Draghi search engines are practically bare hands Antiques and relics. In change, coins, jewelry, household items, and came across the weapon. Can only guess how many were produced for a few years! No one in those times and did not think about using metal detectors.
A curious incident occurred to the author during the spring canoe trip in The Novgorod region. A powerful flood of 1994 cut a break on many portions of the shores of rivers. In one place, not having the metal detector, the author managed find war relics more than all the rest Hiking with the device (by the way, the most interesting finding was the German coin 20 Pfennig 1942).
Therefore, before looking for the answer to the question of what the metal detector is better it should be clarified, and whether it is necessary generally?
Similarly, and with what price you plan to search. And the "hot the minds that adhere to the - "at any price", can thoroughly recommend dig the whole earth in the region of interest and sift it through a fine sieve...
A realistic approach is presented for clarity in the form of a table (see tab. 1) in the coordinates of the "money work".
Table 1
As for the technical side, it's safe to say that the vast number of overseas electronic detectors, designed for serious search, are so-called class VLF-metal detectors (VLF = Very Low Frequency - elf), working on the principle of "transmission-reception" at frequencies 5... 15 kHz. Such devices recommended for self-production.
Novice radio Amateurs can recommend a more simple device on the beating or simplified versions of the detectors of other types, including sets of "do it yourself" company "Master KIT".
Fans of scientific experiment and design search can, in principle, recommend metal detectors of all types. However, according to the author, the most interesting from the point of view of the analog circuitry of the induction type instruments and devices on a transfer - receiving".
Those who have experience with microprocessor devices will certainly be interesting detectors based on single-chip microcontrollers.
Author: A. I. Shchedrin