don't mean to keep asking the same question but can someone explain or post a drawing on the difference of a small coil vs bigger. for example they say there is a different pattern of flux lines that are closer together. staying on the concentric do they all extend past the edge of the coils and by how much? do they extend the same distance on all sizes? are they all cone shaped in the ground? what makes the pattern different? is it the way the coil is made inside? is that why most gold detectors have a coil of only 5 inches wide for the tighter pattern? just trying to get a better understanding if anyone can help or is it a trade secret on how different manufacturers make them work the way they do? any help would be appreciated