I just bought a new F75+,and I have a question that I’ve googled and looked for but cannot find by myself..I’ve been hunting a local park lately,never have until last fall but it has given up some real nice old silvers..So,I got the F75+ and I’m looking at a smaller coil..I have dug a lot of old screw caps there,I mean a lot.And I’m going after coins and jewlery,so can the 3x6 concentric fisher coil do better on identifying screwcaps over the 5 inch fisher coil?