Thanks all, you’ve given me some really good tips and information to go with. I have encountered the mineralised clay ground recently where there has been nothing there once I’ve dug it out. To be fair, in the 8-10 times I’ve been out there has only been a couple of occasions where I haven’t had any finds which is nice and I’ve already got the bug so there’s no chance of me giving up. It’s also nice to hear that others have experienced the same with their machines so at least it’s not unique to me or my machine, so thank you for your feedback.