teknetics delta 4000

I recently got a Teknetics Delta 4000 and still very green with it. I’ve tried following the manual but for some reason my pennies ping the same as dimes. Would really appreciate any and all advice on what settings I should put it on that would best suit coin hunting. Thanks!

[?] is because I know basically nothing about this machine.. I'm an ebay specialist for a company that specializes in store buyouts, customer returns, overstock and damaged goods.. A couple of days ago I was digging through a gaylord full of sporting goods & clothing from a well known...