this morning i took out my new secnd hand deleon for a run here in australia and in a small park close to home that previously i went by without a second glance and found $12.70 in aussie coins.they had been there a while judging by their colour and they were deep.i had the detector sense only on four,disc on tab.i wondered what i would find if i opened it up to full sensitivity.china maybe?is this the norm for this detector?emubnob