There is also several variations on how you use each technique.
Firstly; the shallow technique. It is shown in the post by NM5K and John. (Johns explanation used to be on the Garrett website, but got removed when they revamped the site recently. I don't know why as it is very a useful learning tool.) Both NM5K and John have both given good explanations of how to use this method, so I will only add some refined info to them. I have found that when sliding the coil (either forwards or backwards.It doesn't matter) once the signal drops off, just nudge the coil back to the spot to where you lost the signal. Once there, wiggle the coil as you slide it back again to make certain that it was centred. Often, the first time you slid it back, when you thought it was centred, it's not. This way you can be sure. If it's not centred, then you can miss the target by a couple of inches in either direction. Ouch. Practice in your back yard on some ground that is free of metal. ( Check the ground by waiving the coil over it while HOLDING DOWN the PINPOINT BUTTON, as this is the Aces only true all metal mode.)
The reason that this is referred to as the shallow pinpoint mode, is that is only accurate on shallow targets! Due to the shape of the signal going into the ground (bowl shaped) once a target is deeper than say 3inches, you have to compensate for the signal. In simple terms, the deeper the target after this point, the closer to the centre of the coil it's going to be. Usually only an inch or 2.
The second method, is for deeper targets and is always accurate, regardless of depth. Grab a coin and place it on the cleared ground. Next press the pinpoint button and waive the detector over the coin. While over the coin, with the pinpoint still sounding off, hit the pinpoint button the second time and keep it held in. (Sorry if I'm already talking about what you already know) As you know, this will shrink the target for you. It means also that the front D shape of the inner coil is all that the coin will be picked up in. If you will note that there is a cut out in the middle of the coil. This is the spot where we are going to pinpoint with. Waive the coil back and forth to centre the target (the signal won't be much wider than the coin on both bigger coils, a bit wider on the 12 in coil). If you are not getting a signal, either the coin is to the rear of the coil centre line, or the target was a junk target. Once you have the coil centred, slide it forward till you loss the signal. Keeping the pinpoint button still held down, slide the coil back again till you get the signal again. From the very moment you get the signal, only allow the coil to move about a sixteenth of an inch back; this will put your target SMACK BANG in the MIDDLE of the CUT OUT every time!
The shallow pinpoint method seems to be the most popular method by most, and once you become practiced with it, you will start to notice how different objects sound as the pinpoint drops off (in the top 2 inches at least) and can help to some degree as to what some targets are. But don't put too much faith in it as you can miss a lot of good targets if you do.
I hope this wasn't too long winded.
Mick Evans.
