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Jp’s Gold Thread


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Excellent  thread, JP. I very much enjoyed your instructional DVDs back in the day, as they taught me a great deal about the detectors' features and functions and when to use them according to the different ground types and the nature of the gold being chased. You touched a little bit on the actual prospecting - what grounds and areas you were targeting - but the videos were mainly equipment oriented. So to now have a thread that concentrates on the actual gold finds and prospecting side of things is most welcome. Since you said, "ALL DP members are more than welcome to comment and ask questions about detecting related subjects, especially about targeting locations and mind sets and approach", I'll add an experience here and post pics of it in a separate thread of my own. A couple of years ago I was prospecting an area in the southwestern Arizona desert and picking up a few small bits, mainly in drywash piles (dryblower heaps), when I received a decent, deep sounding signal from the detector in bench gravels above the present dry stream bed, which turned out to be a solid, dense 1/2 ounce beauty of a nugget. I searched the surrounding area thoroughly and turned up a few more small bits, but nothing more of any size. Recently, I decided to target the same area using a different detector mode that is designed to punch deep on dense, sluggy gold. Sure enough, in a spot that I had gone over multiple times before, I got a faint, repeatable signal that ended up being a lovely 2/3 ounce chunk of a nugget at nearly 2 feet (61 cm) deep.

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These are the things that part time, occasional prospectors have a difficult time learning...your experience is the key!

One of the things I loved about my Tours in Oz was that I became one with my detector...so much easier than retraining myself  every trip.

fred

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That last post is a keeper, thanks JP. It's a relief to find that being a fanatic about coil control is a key. It takes another level of concentration to factor in coil control along with all the other things we are paying attention to as we go along, but you can really see how critical it is once you start to home in on a subtle target (that's when most of us use good coil control). I cringe when I think of how many faint targets called out to me in my earlier days of detecting until I finally got it into my head that working slowly and with good coil control was a vital key to actually finding what others did not. 

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These are the things I miss when detecting the desert.  The 'lead in' as you say is the fringe detecting that draws the moth to the flame.  My lead ins are muddled because in many cases I still 'beach detect' the desert.  I'm seeking a larger, noiser target (relative to ground) and I'm not hearing the little warble.

I did achieve on my last trip a level of 'one with the threshold' for periods of time that let me know if a target was there I was going to hear it.  I buried a test nugget and listened and found out that I can't hear little gold (.2 g nugget) when it is over 4 inches or so.  As Lunk has said if you know there are some deep targets in an area then you can adapt or go back with a different timing.

I'm getting better at digging deep trash!  haha

Thanks JP.

Mitchel

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I`m enjoying this thread, despite that my techniques varies from JPs Conservative to Steves Insane with a few other unconventional twists. Plus JP I agree this is how threads should be, thus giving me the confidence that again I can perhaps pass on my positive experiences in my own threads. 

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2 hours ago, Jonathan Porter said:

Gold Catcher, I very rarely adjust the sensitivity away from factory preset on all my machines (except the Equinox, 20 is crazzzzzy😜 in our ground). IMHO increasing sensitivity also increases a lot of the surface clutter so generally I keep things conservative instead relying on the technology to do the heavy lifting. 

I should point out here that there are some differences between what we call the “Smooth class of timings” and “Normal” type timings, inherently the Smooth type timings (difficult modes on the GPZ, Fine Gold, Enhance and Sens Xtra on the GPX machines) have increased Gain built into the timings, they need to do this to elevate the target signal which becomes greatly reduced due to the timings removal of the majority of ground noise etc. I feel increasing sensitivity also increases threshold instability of an already twitchy mode. If you pay attention you can actually hear how busy the threshold sounds in these ground signal reducing modes compared to Normal timings.

Note: On the GPZ the High Yield modes are running quite a bit different Tx/Rx wise compared to the others so have an EMI reducing tendency built in (you will notice you can get a lot closer to other operators in these modes compared to General or Extra Deep).

If I‘m working shallow ground where there are mainly smaller pieces I will increase my sensitivity to around 12 on the GPZ but very rarely any higher, the learning curve required to retrain my brain to not tweak on every little burp and fart in the threshold is just not worth it relative to the slight increase in target signal over ground signal (this ratio basically remains the same no matter what you do).

The biggest issue I find with increased Gain or Sensitivity is the increase in EMI jitters and electronic noise, Minelab machines run a very fine line on all fronts even right down to their noise floor so the electronics and timings are very finely tuned to compliment this. 

In essence my main focus is in coil control, it is so important on so many levels especially when chasing tiny gold in variable environments. The Two major things about coil control are: 

  1. Keeping the coil level
  2. Maintaining a good “Range of Motion”

The detector is tuned for the coil to be held flat relative to the Earths magnetic field, if you tilt it then it allows EMI into the audio and its the worst kind of EMI which is the garbled non-patterned SFERIC type of EMI. You would be amazed how much SFERIC noise kills performance even on the mighty GPZ!

Range of Motion is my super power. Understanding what is required to manifest a deep target response relative to what the coil is actually doing is so important. I imagine the target as being a ball of magnetic energy that radiates out from its centre which is the energised Eddie current infested target itself. You the operator need to have a familiarity in the general ground signal response of your chosen area, as your coil comes into the target zone the threshold response will begin to alter either going from threshold pitch in a raising tone or a lowering tone dependant on which channel is dominant relative to size of target and GB position. This initial change in threshold pitch is what we call the “Lead in” and is generally pretty close to the target epicentre. This is the thing I am concentrating all my energies on when detecting.

As the threshold pitch changes so does the volume which steadily increases till the very centre of the target is reached (this is where the coil Rx comes into the strongest part of the targets magnetic field, where the targets field disrupts the coils Rx the most). Once the epicentre is reached and passed the target signal will start to change pitch again and the volume will decrease till the coils Rx leaves the target zone, this is known as the “Tail out”. The Tail Out is generally much wider than the lead in. The key to manifesting a target response correctly (remember we have no idea if there is actually a target present at first,  its all supposition and guess work most of the time) is to feel around with the coils Rx till you get an impression of the signal area and its epicentre. During this process the GB needs to be kept accurate for the localised conditions not the target zone so be careful not to throw the GB too much when “feeling about” 🤫🤪

IN the case of GPZ and DOD the consensus of this combination is a slow signal response which is ideal for deep slow target signals, you could almost say the GPZ is swing dependant where the sweet spot needs to be searched out and locked into. The GPZ loves a smooth controlled swing that provides a full range of motion relative to the target. Size, shape and depth relative to the aforementioned previous coil speed and range of motion are the key to manifesting the best possible signal response. Getting the coil swing coming in from an averaged localised GB condition where you have to familiarised yourself to detector behaviour for your chosen area is important, some GB states cause the threshold to behave differently sometimes suggesting a slight change in threshold pitch but it will just be the ground and GB interacting with each other.

Achieving a good range of motion and becoming familiar with how deep targets behave is so important, all my settings on the GPZ are solely designed to compliment this. IMHO running higher sensitivity levels blends the “Range of Motion” signal too much potentially degrading identifiable information, especially on the Low/High signals, you need to come from a smooth stable localised ground signal into the “lead in” Stage of the target. I feel having the threshold jittery and coarse through SFERIC noise or the “zoomed in“ Nature of running elevated Sensitivity fights your ability to properly recognise the deeper target signals.

JP

JP great post. I wonder if you could translate the second half which is very technical, into normal everyday circumstance and language. I enjoy technical but sometimes what one word means to you in OZ does not have the same  Nuance in US, resulting in a confusion.

Great to be back to meet and potatoe threads. Thanks JP.

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JP, thanks for the tips and explanations on 

  1. Keeping the coil level
  2. Maintaining a good “Range of Motion”

Always great to have the reminders plus the extra instruction to enhance my understanding of what's going on/what I need to pay attention to.

Nicely done, thanks for doing this, and all the best,

Lanny

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21 hours ago, Jonathan Porter said:

IMHO increasing sensitivity also increases a lot of the surface clutter so generally I keep things conservative instead relying on the technology to do the heavy lifting. 

Thanks, JP. I really appreciate your detailed reply. This is the kind of info that is the most valuable to me and one of the main reasons I joined this forum, just as I am sure it is for many others. We all love our machines (whatever brand), but making the most of it requires an in depth understanding of all settings, their purpose, their best application and the awareness of how important the operator's handling of the detector is. The latter part includes coil/range of motion control just as you say and I thank you for providing your expert opinion on all of these topics.

Ever since I own the GPZ, I have extensively experimented with all settings and often spent 30 min or more over a given target, just to detect it with various setting-combinations before I actually dug it up. I also did field testings with various nugget sizes, shapes and consistencies to familiarize myself with target response and detector behavior as a function of ground conditions, depth, gold-densities/shapes and the way I swing, etc..  Now, by no means I have done a pro-type field testing, but I have tried as much as I can to learn the most of it. One thing that I can definitely conclude from all this is that not one timing/setting fits all situations. This of course should be clear to everyone and is somewhat old news, but surprisingly many operators seem to have favorite settings that they try to use with brute force in all situations, just to adhere to their personal philosophy. I have had situations where HY/normal timings are superior, but I also had many situations where HY/difficult was by far outperforming any normal timing, up to a point where in normal the targets where not detectable at all with everything else being the same. The GPZ is an incredible versatile machine, and in my view understanding what settings to use in what condition is the most important part, rather than adhering to "dogmas" and "one fits all" strategies.

Keep up your great contributions JP.  I know a lot of operators are learning from it (including me)🙂

GC

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