Best Large Coils for Open Fields

Separation in trash is the main cost, and weight is the second. Minelab publishes a weight of 1.46 lb with the skidplate fitted for the Minelab EQX 15 Coil (15 inch), noticeably more than the 10.68 oz Minelab publishes for the small Minelab EQX 06 Coil (6 inch), and that difference is felt on the shoulder across a full day of sweeping rather than in any single hour. On a site with only occasional iron, none of this matters and the larger coil simply finds more, faster. On a site with dense iron, the same larger field starts overlapping multiple objects per sweep and reporting one blurred tone instead of several distinct ones, which is exactly the situation the small coils page exists to solve.

As with the small coils, check the "fits" column first. None of these cross between brands, and the Legend and Equinox coils do not fit each other's machines despite both being simultaneous multi-frequency platforms.

Yes, directly. A wider coil covers more lane per pass, which means fewer lanes to walk for the same total ground and less time spent overlapping your own previous sweep. The coil coverage calculator turns that into an actual hours-per-acre figure once you know your coil width, sweep speed and overlap habit, and the search grid planner takes it a step further into lane spacing for a specific field's dimensions. Both tools exist because coverage math is where a big coil's advantage becomes concrete rather than a vague sense of speed.

Depth on a genuinely large target, such as a cache or a sizeable relic, also improves with coil diameter, though the gain on a coin-sized target is smaller than most buyers expect. The coil size versus depth chart sets out what is actually published on that trade-off rather than an assumed straight line.

Not uniformly. The sacrifice is largest on sites with dense, close-packed trash, where a wide field genuinely blends two nearby objects into one confused tone. On a ploughed field with scattered iron rather than dense iron, a large coil often still separates targets reasonably well simply because there is more empty ground between objects to begin with. The honest way to know which situation you are in is to walk the same stretch of ground with both a standard and a large coil and compare what each one reports, rather than assuming the trade always applies at full strength.

Terrain also interacts with coil size in ways a specification sheet cannot capture. A wide coil follows undulating ground less closely than a narrower one, which can leave the leading edge lifted slightly off the surface on rough pasture and cost real depth that has nothing to do with trash or discrimination at all. Slower, more deliberate sweeping recovers most of that loss, and it is worth practising specifically when a new, larger coil is fitted for the first time.

Give a new coil a short settling-in session on ground you already know well before trusting it on a new site. Sensitivity that was correct for the stock coil is rarely correct for a coil several inches wider, and running the same setting unchanged is the most common reason a new large coil disappoints on its first proper outing rather than the coil itself being at fault.