Who Has Had Issues With Their Gpx 6000?

[WesD]

I experience something similar Jason, In my case I  notice there is a lot of dead zone on the coil when swinging a tiny target over it.  The target in scoop or hand, has to be passed right over a "hot zone" on the coil, or its easily missed/ ignored by the detector.

[jasong]

That definitely could be it, or part of it. I've noticed more dead zone on this coil than an older GPX mono too.

I think when the weather warms up I'll try doing some coil testing to try to understand this coil a bit more and how it acts at depth and with different target sizes. 

[Gold Catcher]

1 hour ago, jasong said:

I'm pretty sure it has to do with speed. As it almost never happens when I run the scoop slowly. It's totally random though, same speed and same target will be heard one time and then not another. 

That happened to me several times. Slow scoop sweep and shaking the scoop before sweeping (so the heavies go to the bottom) usually always does the trick. Every scoop I repeatedly sweep slowly over the coil edge and also from different directions before I toss it. It takes a bit more time, but I have lost several targets by not being as careful like this. I also noticed at times an audio delay, which combined with sweep speed could contribute to loosing targets. It does not happen often though.

GC

[jasong]

I guess the larger concern I had wasn't so much losing the targets in the scoop and tossing them, but the fact that I noticed I was losing targets in ground too. And not just faint or tiny ones, some really obvious targets were just not there at all the first pass. They weren't targets I would miss normally for the most part, and it has now made me wonder how often that happened in ground I didn't redetect.

If it's a coil dead zone thing, it might mean a lot more overlap is required than I was thinking, which slows things down. If it's a CPU glitching thing, then it requires slowing down and/or more overlap to cover things twice in case of glitch.

In any event, while it doesn't appear to be a manufacturing defect, it is a potential issue with a machine that really is designed to be faster and easier to use than the GPZ in my eyes, and thus potentially something the engineers (or newest round of 3rd party coil manufacturers) might be interested in improving upon if possible.

[phrunt]

Are you sure it's not doing a Gold Monster and tracking out the target? After all it has auto tracking on all the time?   I guess this would only happen with tiny targets and you're mentioning it's happened with bigger targets too?

[Jonathan Porter]

The flat wound coils on the 5000’s do the same thing. I just had a GPX17 returned because the customer swore the coil was NOT sensing targets at the 10 to 11 O’clock position!! ? ? (physically impossible but I was forced to go and test it any way and sure enough perfect), looking at the coil I could clearly see scrape marks in the plastic where the scoop had been passing through that zone along the direction of the windings rather than across them. 

If you look at the 6000 coils from above you can see an indent line in from the edge, that’s the width of the windings, in essence they are semi flat wound and as such the target needs to traverse that whole section (from edge to the white line) to be sensed by the coil, scoops are generally angled on the bottom so as you move your elbow away from your body to scrape the scoop over the winding the angle will change ever so slightly relative to the position of the target in the scoop. If possible you should always run the target at direct right angles to the windings not along the windings to let the coil see the whole target relative to movement etc. I always give the scoop as vigorous shake back and forth and pass over the coil again on scoop with no target signal just to be sure. 

Also make sure your coil is a flat as possible relative to the earths field when you’re retrieving a target, any sort of angle lets in EMI and that will drown the small targets by a huge amount.

Not saying this is the reason behind the above comments just my observations using the incredibly ultra sensitive GPX6000.

JP

[jasong]

5 minutes ago, phrunt said:

Are you sure it's not doing a Gold Monster and tracking out the target? After all it has auto tracking on all the time?   I guess this would only happen with tiny targets and you're mentioning it's happened with bigger targets too?

Could be that too, I'm unsure. I never had any problem with my 4500 tracking out targets in my soils though, in fact I tried to make a video on it a long time ago and nothing I tried could make it track an actual nugget out, but it was just in mild to medium soils, I rarely find myself in hot ground.

3 minutes ago, Jonathan Porter said:

Also make sure your coil is a flat as possible relative to the earths field when you’re retrieving a target, any sort of angle lets in EMI and that will drown the small targets by a huge amount.

My coil control definitely isn't as rigid as some other people here. But that it happens when my coil is flat on the ground when I'm recovering a target in a scoop, and also while swinging/pinpointing, makes me think that isn't the case.

I have a pretty well worn scratch pattern on my coil from my scoop recovery that shows I'm running pretty close to the shaft, directly across both the back and front of the coil, not along the side of it.

I ran flat wound coils exclusively on both the GPX and GPZ after they became available (aside from the concentric), but I definitely didn't miss anywhere close to the number of targets on those. So I'm leaning towards not just a flatwound issue, but I have no idea.

I'm not too sure if it's one thing or a combination of things up to an including operator error at this point. But I definitely do know I've tossed out and/or missed more targets in 6 months with the 6000 than I did my entire detecting career with the 4500 and 7000 so I figured it was worth putting out there.

[Jonathan Porter]

We all toss out targets and yes the 6000 has a much higher proportion of them, target size on the 6000 is not so relevant as its signature. It is seeing targets from a ‘time constant’ POV that other machines just pass over including the 7000. This is why when you come from a slightly different angle a target will pop and blow your ears out yet was completely missed, it’s just the nature of the mind boggling sensitivity of this detector.

Passing a target over the coil in a scoop does exactly the same thing, booming signal one second and barely audible the next and you’d swear you’ve changed nothing. It’s frustrating at times (especially when you toss the nuggy into tussocky grass!!! ?) and makes NO sense but it is what it is and part of the price we pay to keep in the game.

You’re not going crazy and your machine isn’t broken its just the nature of GeoSense and an indication of what the 6000 can achieve, more importantly it shows just how far Minelab have pushed the envelope of PI, just incredible.?

[dig4gold]

Tossing your scoop discards willy nilly into the never never is a bad practice. I have always just placed mine in a careful pile beside the dig/scrape, so if what happens as is being discussed here one can go back to the "waste" pile for reevaluation if they have inadvertently "chucked" out the item that was the cause of the signal.