owassokie -- this is not an issue specific to your machine, as others have noted. Mine does it as well.
I THINK I have figured out this pinpoint issue, or "bug" as some are calling it. Bear with me here, as I will try to explain, but is a bit tedious to explain, and thus I need a bunch of words to do it!
I think this "issue"
occurs when you initiate pinpoint mode, and unbeknownst to you there is accidentally a SECOND target under the coil (i.e. not your "target of interest) right as you press the pinpoint button. For instance, let's say you locate a target of interest, and so you move the coil a foot or so to the side of the target and initiate pinpoint. IF you happen to initiate the pinpoint over or near a SECOND target that is in the ground, the "auto-tuning function" in the pinpoint mode -- i.e. the way the pinpoint mode accomplishes its goal of giving you the proper, modulated VCO audio (i.e. quiet for deep targets, and loud for shallow ones) gets "messed up" by that "other adjacent target."
Let me offer a simplified illustration, but one I believe is roughly correct. When you engage pinpoint, what that mode of course tries to do, is give you -- through "modulated" audio -- an idea of how deep your target of interest is; soft sound for deep/weak signals, and loud sound for shallow/large targets. But to accomplish this, the pinpoint mode when first initiated has to be "baselined" over CLEAN ground. I think it uses sort of a "differencing" process, comparing signal strength when it was "baselined" to signal strength of the target, and then USING THAT DIFFERENCE BETWEEN TARGET AND BASELINE, gives a modulated audio response (loud, or soft).
So, let's say you locate an ISOLATED (clean ground) silver dime, 4" deep...no other nearby targets present. You move the coil a foot or so to the side of the target, and initiate pinpoint mode. Now, the unit quickly "baselines" itself to CLEAN GROUND (no target under the coil). Let's say, for illustration purposes, the clean ground signal strength is a "1". Now, when you move over the dime, it measures the signal strength of the silver dime, and let's say the dime strength is an "8." So what I think the machine does is takes the "8" strength of the target, subtracts the signal strength of the ground ("1"), and now, signal strength is "7". And I think it is this "7" that the modulated audio algorithm uses, to output the audio. So, in this case, the algorithm reports a relatively strong "7" signal by assigning this "7" a "loud" volume level, thus correctly telling you the target is shallow (or large).
HOWEVER, consider the same scenario, same 4" silver dime, but this time, when you move the coil a foot to the side of the coin, let's say you accidentally, unintentionally initiate pinpoint
over the top of a second, target. NOW, the pinpoint "baselines"
to this second target, instead of baselining to clean ground. And let's say this adjacent target's signal strength is a relatively strong "6." So now,
6 becomes the "baseline." And so now, when you move the coil over the top of the silver dime (again, whose signal strength is "8"), the machine takes the 8 signal of the dime, subtracts from the "baseline" signal of 6 -- which the algorithm incorrectly assumes is a GROUND signal, and thus when the differencing occurs, you get a difference of 2. And so now, the modulated VCO pinpoint sound of the dime is very (inappropriately and incorrectly) quiet (as it is using "2" as the signal strength to assign audio volume to). So, at this point, you either need to move the coil over CLEAN ground for a few seconds (so that the machine can eventually, automatically "re-baseline" itself), or else just turn off pinpoint and re-engage, over clean ground, "forcing" manually a "re-baseline." Then, things go "back to normal," with correct (not quiet) pinpoint audio.
Now, this is just a simplified explanation; what is actually going on I am sure is a bit more complicated than that. BUT -- after using the machine now for 6 months, I'm almost sure this is essentially what is happening. In order to give us that nice, modulated audio, that "ramps up" over the top of the coin, and then "back down" as you move the coil off the coin, and is appropriately "loud" or "quiet," depending upon size/depth of the target, it's IMPERATIVE that when you initiate the pinpoint mode, so as to "baseline" the VCO audio algorithm, that you initiate pinpoint mode over CLEAN GROUND. And this can be difficult in ground that is filled with targets.
THIS is essentially what I believe to be happening. I think if you simply assume in your mind that when you engage pinpoint mode, and you move the coil over the target, and the sound is really, really soft, ASSUME that you must have initiated pinpoint mode over the top of, or at least near, a SECOND target. So, simply turn pinpoint mode back off, and then re-engage it in a slightly different location (maybe a foot away from the target, but on a different side of the target of interest). 99% of the time, this works for me...
Steve
