Roni,
First, I would suggest that you search through the previous posts on the subject of pinpointing, Second, I would make sure you understand what the manual has to say on the subject. Everyone has their own ideas on pinpointing and I will offer you a few thoughts.
All references to the manual are the Explorer II manual.
THE DD COIL IS WILDLY DIFFERENT THAN MOST OTHER COIL DESIGNS
The manual does not say much about the DD coil, but page 60 gives you the basic idea. The DD coil is designed to produce a magnetic field that is relatively constant under the entire center strip of the coil. For this reason a target under the coil will sound about the same regardless of where the target is anywhere along that center strip of the coil. You can verify this as follows:
* Lay the detector on a non-metalic table with no metal objects in close proximity.
* Slowly "wiggle" (about a 1" side to side movement) a coin about 3" away from the bottom of the coil.
* Continue to "wiggle" the coin while moving the coin along the center strip of the coil from front to back (or back to front. It does not make any difference.). You will notice that the sound produced by the detector is about the same regardless of location of the coin as long as it is directly below the center of the coil. But as soon as the coin goes beyond the front or back of the coil, then the sound abruptly disappears.
This behavior makes it difficult to know just where the coins is other than below the center strip of the coil.
THE OUTER RIM OF THE COIL WILL ALSO PICK UP SHALLOW TARGETS
Now do a similar test to that above, but "wiggle" the coin VERY CLOSE to the underside of the coil (less than 1"), but away from the center strip of the coil. You will notice that the detector will also strongly indicate a target when the coin is under the OUTER ring of the coil. This is true around the entire circumference of the coil. This can cause a lot of confusion for targets near the surface of the ground. If the target is a coin, then you will notice that the detector tone will fall off quickly as the coin is moved farther away from the coil.
SUGGESTIONS ON PINPOINTING.
Follow the instructions on page 60 of the manual with a slight modification.
* While "wiggling" the coil over the target, then move the coil back towards you until the target tone ceases. At this point the target will be almost directly under the front edge of the coil. Having done this, then focus on spot on the ground where the tone ID ceased.
* Now approach the target from an angle 90 degrees as suggested by the manual (It is probably best to have the center of the coil passing over the target spot on this pass to get the best response).
ABOUT USING THE PINPOINT MODE
Most people become very proficient in pinpointing with the Explorer II without using the PINPOINTING mode. But, for the less experienced, I have found that using the PINPOINTING mode will allow one to very accurately determine the location of the target.
SUGGESTIONS FOR TARGETS CLOSE TO THE SURFACE
For targets that are close to the surface on can simply raise the coil a few inches off the ground while going through the pinpointing process.
Hope some of this is helpful.
HH,
Glenn