emi

I got a Eurotek Pro a couple weeks ago I like it and have some questions. I'm using the 8'' concentric coil in mild ground. My target ID is not very accurate it usually bounces between 4-5 different numbers at almost all depths on coins is that normal? The ID seems so unreliable I don't use it I...

I received a Fisher F4 I purchased on eBay today. I went to bench test it and it went haywire. Figured EMI from inside so I went outside. Not any better but I was able to air test some coins and pull tabs. But when not reading it was still all over the spectrum. I don't think the EMI could...