I read this post last night. Rain stopped, took my Silver U Max (aka "SIR") over to the school yard, set Sensitivity down, stock coil, disc at Iron.Worked parallel to chain links, got signals. You have to work them....Nothing to dig with , used shoe and got a pop tab , cent. And can slaw..No other locator I have ever had will get in this close..Stock coil...haven't ordered a smaller one..The metal posts will kill the Silver..THEN, went to an area I have never been able to work. Drove old T 20, to fits, 1210, and all the other Fishers to distraction..Darn old Silver went over the ground like down town..Only noise were signals, some clipped, some good healthy foil? The soil here is clay. The hot rock area was a load of gravel etc to make a path, lot of iron in it..Just sent a PM. taking wife to dinner, and, then need to carve a Santa for a charity raffle..So, if there are any experiments you want tried,,,like Annie sang, Tomorrow.. Have a great day NAD