GPX 6000 Manual Vs Auto Preference

[Dutchman4]

Now that there are many man hours on the GPX 6000 by experts, I would like to know opinion or field experience of using Manual gain vs Auto or Auto+?

I remember reading somewhere that the Auto settings can result in a higher effective gain result than even Manual 10 (max) but I dont know if this is a fact or just an opinion.

I have mostly used Auto from the beginning but wanted to know what other use and under what conditions.

[phrunt]

While I'm no expert I've noticed a few things from time to time, the same was said about the Gold Monster, that in Auto+ it can run higher sensitivity than in manual 10, I find that incorrect, I'm in very mild soils and ALWAYS find manual 10 better, even in a simple air test with no ground at all manual 10 wins.  I'm in ground where VLF's like the Gold Bug Pro don't get a ground response pumping the coil from turn on, and are right at the bottom on mineralisation bars, often none.

Then along comes the 6000 and it was said the same thing that Auto+ can be more sensitive, again I just don't see it, it's not for me, very simple to test by flicking between the two on very faint targets, the manual mode is always better.  I don't know how mild your soils would have to be to see Auto+ improved over manual but I'm certainly not mild enough, and if I'm not who would be?  Perhaps the person testing in using some Styrofoam for soil or something in an EMI controlled lab may have found Auto+ had an edge but in the real world, it's not for me, it lowers the sensitivity not allowing you to put up with a little bit of instability to get better results.  It would be cool if in Auto or Auto + it had a little display showing what manual mode equivalent it was in at the time to get an idea of what it's doing.

Auto+ was said to be able to go higher than manual if ground conditions and EMI allowed it, well I'd be the perfect candidate for that I think, yet I don't see it.

[Jeff McClendon]

I agree with Phrunt. GPX 6000 manual 8 to 10 allowed me to adjust sensitivity and ground balance for my ground conditions instead of trusting some AI in the GPX 6000 to adjust sensitivity and ground balance on the fly and hopefully get it right and keep up with changing conditions while using Auto+.

[Gold Catcher]

I mostly use manual (threshold always on). Auto appears less stable for me most of the times. Re manual, don't be afraid of reducing gain if needed. It will remain very sensitive with only a marginal loss at depth. I like 7 or 8 in Normal. It then will get nice and smooth, so nice for a change. And I never had a single case where I heard a signal at 10 but not at 7 or 8. 🙂

GC

[Dutchman4]

Thanks guys for the info.

[jasong]

Agree with others. Another issue I found with the auto setting on the 6000 is that it appears to "remember" past auto adjustments beyond the point of time those adjustments were needed. And you have no way of knowing what it's currently set to. For instance if you hit some massive iron, leave your coil over it, it will back off the sensitivity. Sometimes it adjusts back quickly, other times it takes longer, and in one case where I was testing that phenomenon in air it simply never readjusted, even after turning off and back on! I was suspecting for a while it was doing this while detecting highly variable ground too - going from magnetite saturated soils to regular soil (stream banks/bottoms, etc), and the machine was desensitizing itself and staying that way. 

It also appears to adjust sensitivity based on varying EMI conditions too, but I'm not 100% positive on that. 

It's impossible to know what's happening, and it seems to have a mind of it's own, it's hard for me to get some measure of repeatability to say anything specific. There is no graphical readout displaying the current settings in Auto either, so who knows.

And I alllllmost suspect it's doing this same adjusting to a lesser degree in Manual too. In fact, I was confident that was happening to some degree last year, but I forget exactly why I drew that conclusion now. I think this is part of what "Geosense" is. 

That said - I use the 6000 for 90% of my detecting now, and I'd say most of that time I still use Auto+. For general exploration it's just not required to try to catch everything, and most the targets are easy targets anyways. So, I just use the quietest, fastest method, and that is Auto+. If you are reworking patches or small areas though, Manual would be the way to go.

 

[dig4gold]

I agree with Phrunt, as we both live on the South Island of New Zealand, I at the top end & he towards the bottom end. Our ground being very mild I too favoure manual 10 over the Auto settings, threshold on & usually get away with full max sensitivity but not always.

D4G

[Jonathan Porter]

There’s a key comment here that tells you a bit about what’s going on under the hood in Auto+. 

1 hour ago, Gold Catcher said:

Auto appears less stable for me most of the times.

That is a sure sign the ‘gain’ has been increased over manual mode.

Manual mode on the 6000 behaves differently compared to a traditional Gain or Sensitivity control. As you lower the manual control you notice a gradual settling of the upper flutter in the threshold but sensitivity to near to coil target signals still sound bright and clear just slightly subdued relative to the manual filter* position, which flies in the face of a traditional gain control. 

In Auto modes there are two things happening simultaneously and they need to be in alignment for best performance which requires careful control from the operator. Or you can just not worry about it and let it do it’s thing when the conditions call for it. As an example ALL stick shift drivers complain about auto gear boxes in 4x4 vehicles, even the later 10 speed designs, they never get it 100% right.

For max depth with  the 6000 you need to run Max manual sensitivity, that is by far the best detecting scenario IF conditions will allow. This is why I like the new Nugget Finder 12x7 Xceed coils, they were designed from the ground up to work in hot variable soils so run very quiet allowing max manual sensitivity. Max manual sensitivity opens up the sensitivity filter to provide max edge of detection response, once again assuming the conditions will allow it. The NF coils have a natural mellowness to them which then flows through to the end user especially in hot ground. The main aim being opening up the sensitivity “Filter” (*for want of a better term) to get max information through to the end user.

In super quiet soils the ground balance has nothing to work against so target sensitivity can actually suffer, suggest operators carry around a mild hot rock and ground balance to that occasionally and see how things go. One of the reasons why I don’t like a full auto GB and prefer to have the ability to FIX the GB. Put the hot rock on a string and throw it down every so often, sweep over it holding the Quik-Trak button in to help keep the GB centred and averaged, give it a try you might get a pleasant surprise.

JP

[Jeff McClendon]

It's always great to hear from you JP.

Thanks!!!!!

[Gold Catcher]

Thanks, JP. I usually use max/manual but don't shy back reducing gain and enjoy the smoother threshold if I know the gold is shallow. I have tried Auto as my first line of defense when manual/max get's too unstable, but found that reducing gain is often the better option. Good to know that in auto the gain can be increased, even though the gain was already at max or close to max in manual. I wonder though why the Auto algorithm would not notice that the gain is already too high (probably the main reason for instability if everything else is optimized as good as possible) and reduce, rather than dialing up. But for sure, a lot is going on under the hood and thanks for your detailed explanation. Love my NF 12x7, hardly ever change it. Same for my Zsearch 12.  😁

GC