The frequency of the coil directly affects the sensitivity and search depth. In this regard, the 7 kHz detector is prepared to offer the treasure hunter a wide range of targets and a relatively large scanning depth. A low frequency is characteristic of longer wavelengths, which penetrate the soil layers much more easily. Of course, this affects the proportional decrease in the sensitivity of the coil to small objects, but not much.
A metal detector with a 7 kHz elliptical coil is a universal option for working in the field, which implies a large amount of digging. This device will prove to be excellent at detecting targets such as jewelry and medium-sized coins, relatively large items from the times of World War II, as well as small flake coins. Among the shortcomings of this coil is the difficult work in the ground, which is characterized by increased mineralization, and a decrease in sensitivity against the background of electromagnetic interference.