Without a doubt, metal detecting is an exciting hobby. Most people, having at least once spotted a valuable target like old coin, relic, or jewelry, cannot stop with this hobby. With time, treasure hunters want more, and start looking for ways to improve their search sessions, to reach higher productivity. One of the ways to do that is purchasing additional search coils. However, considering the number of options, the choice becomes complicated. So, let’s find out what coils are available on the market, and what each of them does.
Size of the coil defines the depth of reach, and influences the sensitivity of detector. The main rule is, the bigger the coil, the bigger is the scope it covers, and the bigger is the depth of reach. Obviously, bigger depth of reach is worth paying for, and you probably want a bigger product in your kit. However, big coils are less sensitive to smaller objects, at the same time being more inclined to catch electromagnetic interference. As a result, you may face the situation when you have to decrease the overall sensitivity just to avoid the interference.
Smaller coils, in their turn, work better with small targets, and are more resistant to all kinds of interference. Those coils are also handy when working on narrow locations, where you are limited in space.
In practice, to find coins and deep targets, you want a bigger option, and on trashy locations, where small finds can be burried together with metal objects of all kinds, small coils will be more effective.
If you are more into prospecting, big coil is your choice. Firstly, in the majority of cases, prospecting happens on remote locations where the interference is almost absent, so big coil will give you scope and depth. On the other hand, small coil will find nuggets close to the surface.
Shape may turn out to be crucial for effective search. Round coils are the most widespread, because they show stability in performance, and have the best tech specs. Other shapes are often handy in different specific conditions.
Overall, elliptic coils are more manoeuvrable in the forest and when there are big objects on the location, at the same time, they cover the same scope of combing through as round models do. Open-air design, in its turn, makes the coil lighter, and improves search in shallow waters or underwater.
Concentric coils have their transmitting loop along the edge, while the receiving loop is in the middle, together making a conical shape of signal. Such configuration requires the most thorough overlap of every swing, but it is the most efficient when spotting the targets.
This is a very popular coil configuration, having two D shaped loops overlapping in the middle. They shape the signal in the form of a knife, making it powerful and very exact. DD configuration is stable in performance, provides a considerable depth of reach, good ground balance, and you do not need to overlap mush when detecting.
Mono configuration suggests only one loop along the edge, that receives and transmits the signals. This type gives the best depth of reach when treasure hunting, even compared with DD one. Yet, its ground balance is worse, especially on highly mineralized soils.
In the conditions of frequent interference, or high ground mineralization, or on salty beach, DD configuration may turn out the best choice.
It will be fair to state that an additional coil can add to your metal detector features, and increase the productivity of treasure hunting. Regardless of what aspect you’d want to tap into – depth, discrimination, or bigger range – there are coils that can meet your demand.