hi everyone,
i'd be so grateful if you have any suggestions to help me with a problem .i was asked by a friend if i could find a platinum ring that he lost on a sports field

.i've never found anything made of platinum before so i was eager to start but hit trouble straightaway.i'm getting a strong signal every few inches,it's usually a ringpull,pre decimal coin,bottle top or football stud

.i'm using my trusty fisher 1266 with discrim 1 set at 3 and discrim 2 set at 6.anyway yesterday was my third crack at finding it and i've got blisrers on blisters!!

.i'm having to dig about 120 items everytime,i'm frightened of turning up discrim too high in case i knock out the ring.any advice would be much appreciated.
many thanks
chris