Hello I have a question I have been metal Detecting for a long time But bought a New 1500 and So far I Love it the Problem I am having is Some times I can not get it to lock in on the target. Even when I get a good Bell Tone it seem to look but never find it I have worked slow and moved all around to pin point as close as I can. But it will not lock in after digging and retriving the coin I check for other metal and not finding any I am not sure why it does not lock in, when its a coin I have looked all around and could not find any junk to through it off is their a secret to pin pointing with the 1500?