Semi-Elliptical Metal Detector Search Coils

In clean or moderately contaminated ground, yes - a larger coil reaches deeper on good targets by exposing a wider electromagnetic field. On trash-heavy sites, the advantage reverses: a larger coil sees multiple targets simultaneously and produces confused signals, making target ID harder. Larger coils are the right choice for open clean ground where coverage and depth are the priority. Small coils are the right choice on dense sites where target separation is the challenge. See the full coil collection.

A DD coil uses two D-shaped windings to produce a narrow detection field down the center of the coil — better target separation and more stable performance in mineralized ground. A concentric coil produces a cone-shaped field covering the full coil face — good depth in clean ground but more susceptible to ground mineralization noise and less effective at separating closely spaced targets. For most hunting situations in variable soil, DD is the better choice. The stock coils on most modern detectors are DD for this reason. Concentric coils have advantages in specific clean-ground applications where their cone-shaped coverage is an asset.

For most major brands — Minelab, Garrett, Nokta, XP — there is a selection of aftermarket coils from manufacturers like Coiltek, CORS, and Detech that are designed for specific machine compatibility. The connection type and operating frequency must be compatible with your detector. Use the brand filter links below to find coils confirmed compatible with your specific machine. Aftermarket coils often provide meaningful improvements over stock coils at lower cost than buying a new machine.

What size coil should I use for beach detecting?

For beach detecting, a medium to large elliptical or round coil covers the most ground per session and reaches adequate depth on rings and coins in wet sand. Very large coils become unwieldy in surf conditions. A stock-size coil works well for most beach hunters. If you detect in areas with heavy trash concentration - busy public beaches near swimming areas - a smaller coil for better separation may help. For open beach detecting, maximize coverage with a larger coil. See elliptical coils and round coils.

Elliptical coils are the most versatile shape for general use - more maneuverable than round coils in tight spaces while providing the target separation and ground coverage that most hunting situations require. Manufacturers ship elliptical coils as stock because they handle the widest range of detecting situations effectively without the specific strengths and weaknesses of round coils. For open-field prospecting and maximum coverage, round coils have advantages; for general coin, relic, and park detecting, elliptical is the practical choice. See all search coils.

For most relic hunting on moderately iron-heavy ground, a medium elliptical coil (9-11 inches) is the standard recommendation - enough coverage and depth for typical relic targets while still providing reasonable target separation in moderate trash. For the most iron-dense competition sites where target separation is the decisive factor, a smaller elliptical (5-7 inches) resolves individual targets better. For open field relic sites with lower trash density, a larger coil adds depth and coverage. See elliptical coils.

A larger elliptical coil will typically improve depth on good targets in clean or moderately contaminated ground. A smaller elliptical coil may actually reduce maximum depth on deep targets while improving target separation in trashy conditions. The improvement you get depends on the site: at open clean sites, a larger coil adds depth; at dense trash sites, a smaller coil finds targets the larger coil missed by resolving them from surrounding signals. Coil upgrades deliver the most value when you match the coil size to the site conditions you regularly hunt.

Both shapes refer to the outer coil form (elliptical vs round), while DD and concentric refer to the internal winding configuration. A DD elliptical coil has two D-shaped windings producing a narrow detection field down the center - better target separation and more stable performance in mineralized ground. A concentric elliptical has nested winding rings producing a cone-shaped field - good depth in clean ground, more susceptible to ground mineralization. For most hunting situations and variable ground, DD configuration in an elliptical shape is the better choice. See all search coils.