i have noticed that I will get a good hit but when I pass back over the spot it goes silent but I can see that that Safari is tracking the object and when I dig it is always Iron but the numbers are 35 37 39 and it drives me crazy not to dig but should I not dig when the noise cancels out and no matter how much I circle I do not get a good sound? not sure if I am wasting my time or need to just keep digging, or do not dig until I have a constant high tone even if it is just a chirp or two???????????