Has anyone ever given any thought to what might be the optimal relic hunting coil? What size and what configuration (concentric or DD)? Seems to me that it would have to balance seperation with depth. I just can't seem to come up with one coil that is universal enough in a relic site. I either have a coil that has great seperation (the 6" DD comes to mind) and decent depth, but no real coverage, or a larger coil (10"+) that covers a good amount of ground and gets great depth, but has lousy seperation. Assuming the perfect coil doesn't really exist, how would you design The Relic Hunting Coil?