Coils

What is a Search Coil and Why is it Essential in Metal Detecting?

A search coil, often overlooked, is the heartbeat of a metal detector. This flat, generally circular disk, doesn't merely exist for aesthetic appeal but serves a functional purpose. It's responsible for creating a magnetic field, which in turn senses and identifies metallic items in the vicinity. Attached to the control housing by a meticulously wound cable along the stem, the search coil rests at the detector's base, readily touching the ground as you venture in your search.

A notable feature is that the breadth and intensity of this magnetic field directly correlates with the shape and size of the search coil itself. Thus, a deeper comprehension of the various coil sizes and designs is not just beneficial—it's crucial. This knowledge equips metal detecting enthusiasts and professionals with the insight to select the most optimal search coil tailored to their specific hunting scenarios.

Diving Deeper: Search Coil Depth and Functionality

When discussing the detection depth, it's generally accepted that a search coil will detect to a depth roughly equivalent to its diameter, especially when it concerns a coin-sized object. Yet, this isn't a one-size-fits-all rule. With an increase in the search coil's size, its field pattern expands. But there's a twist: the expansive field pattern, although covering more ground, might not be as concentrated. This means it can often overlook smaller objects. For those using search coils with diameters beyond 15”, this dispersion becomes quite evident.

Why does this matter? Large search coils, given their expansive, deeper, but less focused magnetic field, are your go-to when your objective is to find items that are characteristically large and nestled deep within the earth's embrace. Think of treasures like caches or age-old relics that narrate tales of yesteryears.

In a nutshell, understanding your search coil is the key to optimizing your metal detecting adventures. Whether you're a hobbyist or a pro, the right coil can make all the difference between a fruitful hunt and a missed treasure.