The day started crisp, clear and cool. Chris and Steve were now well and truly immersed in the adventure, having perfected their Australian detecting techniques over the previous few weeks to the point they were now naturally targeting productive areas with their GPX 5000s.
The day previously, Steve, Chris and I were working an old scrape taking turns to detect the richest sections of ground where cap rock was exposed (cemented wash with gold enclosed), assisting each other with hammer and chisel to remove the nuggets. Due to the restricted space Chris decided to go for a wander in the hopes of turning up a new area, returning at knock off time he informed us he’d found what looked like someone's old patch. Around the camp fire that night, it was decided we’d all have a crack at the location early the next day in the hopes our GPX 5000s would provide us an advantage over previous operators.
Taking a walk through the area, we collectively decided our best chance was to use smaller coils in combination with the Fine Gold Timings, targeting the richest sections marked clearly by all the chain marks, dig holes and foot scrapes. I spent a fair bit of time filming, so by the time I got my gear organised the guys were carefully working the main areas. With that in mind I decided to put on the 18” Commander Monoloop and work the deeper ground.
One of the big surprises with the GPX 5000 is the improved Enhance Timing which seems to have become lost in the whirlwind of enthusiasm for the new Fine Gold Timings; due to me using a large coil I felt it would be better to use the less aggressive Enhance Timing. Enhance and Fine Gold provide similar depths on large nuggets, but Fine Gold is definitely better on the smaller gold. However, the whole point of using a large Monoloop coil is to get the depth, so small gold wasn’t my focus.
Walking slowly and carefully down through the deeper sections, I noticed a shallow dig hole off to the side of a track. So I decided to wave my coil over it to see what it was that attracted the original operator to dig, considering any gold present would have to be quite deep (gold being heavy tends to settle on or near bedrock). I was amazed to hear a positive, but faint low/high response that sounded sweet to my ear and much deeper than the scrape suggested, meaning the target was still in situ and had been left for some reason (probably mistaken for a ground noise).
The resulting video footage tells the rest of the story. But before I go by way of explanation please note the difference in signal response between the Enhance Timing and Normal. This is some of the best footage I have ever taken, clearly demonstrating the power of the Minelab detectors and why the GPX 5000 is described as being 8 detectors in one! In this instance the ground noise, although not extreme, was masking the signal whereas Enhance was booming it in! The lesson here is to always go over productive ground using a number of different Timings to avoid leaving a nice nugget in the ground.
Lastly you’ll notice I remark about the tonal response. If a nugget makes a low/high response in both Enhance and Normal Timings there’s a high probability it will be larger in size. I hope you enjoy our fourth instalment of “The West Australian Adventure”.
Jonathan Porter
Comments
It was fascinating seeing Australia through the eyes of others but was most interesting was learning about the geology, I think Treasure Talk readers will enjoy some of the upcoming material we have in store for them.
I have to say though it impressed the heck out of me when you showed me that tiny little nugget you found with the 18" Monoloop coil, those Fine Gold Timings sure got a work out during your stay!
JP
With the more distinct Enhance Timing target signal you recieved compared to Normal Timing, you seem to be illustrating that deep targets (both small and large) might best be found with Smooth Timings and large Monoloop coils. Am I missing something?
Minelab's relative depth Timing graphs and the Timing matrix for the GPX 5000 seem to imply that deep, small and large gold targets might best be detected using the "Powerful Full-Depth Timings" (Normal, Sensitive Extra & Sharp) - especially Sensitve Extra and Sharp.
Referring to the relative depth Timing graph, Timing matrix, and also pages 57 and 58 of the GPX 5000 Instruction Manual, Minelab states that Double-D coils and the Sensitive Extra Timing (for small targets) and Double-D coils and the Sharp Timing (for large targets) are the preferred course of action to gain extra depth over Normal Timing - not going to Enhance or Fine Gold and Monoloops as you did. Of course, Double-D coils are the traditional way that many were managing variable magnetic ground noise.
If you were hunting the same large (~17 gram) nugget with an 18" Round Double-D, whould the signal have improved as much in Sharp as it did using the 18" Round Monoloop in Enhance?
Put another way, is it true that your video demonstates that deep gold (of most any size) is best detected with large Monoloop coils in the Smooth Timings versus large Double-D coils in the more agressive PFD Timings (as the Timing graph/matrix and manual imply), and that the reason is due to the exceptional magnetic ground noise cancelling capabilities of the Smooth Timings?
Cheers,
Mark
If the GPX 5000 had been the first MPS detector Minelab had released then operators would for sure be leaving gold in the ground if they exclusively used the Smooth class of Timings. If you look at the current situation, detector enthusiasts worldwide are experiencing the exact opposite by targeting old patches like we did in the video and gleaning more gold that’s been left behind by the previous models using the older timing options.
Double-D coils provide a ground ignoring capability that’s inherent in the design; the Double-D design however also allows discrimination. Due to the mineral ignoring capability of Double-D coils and other electronic limitations it is not recommend the Smooth class of Timings be used with Double-D coils, however the Normal, Sharp and Sens' Extra Timings all lend themselves well to allowing operators to work problematic areas that a Monoloop coil in the same Timings might struggle with. However a Double-D coil in the above Timings can produce ground noise and spurious responses on variable ground, something a Monoloop coil in Smooth type Timings will not be so bothered by. Any noise created by anything other than a target has the potential to mask a target; in a lot of cases the noise created by the ground is very subtle and has the potential to hide what we are looking for.
We also have to consider that each and every nugget has a unique signature in its own right, so much so that it renders developing discrimination very difficult. This is why the GPX 5000 has so many Timing options to allow operators to go over their favorite areas with a variety of Timings to see which one might develop a recognizable signal on missed targets against the background noise. The Smooth class of Timings comes at a compromise to some extent, some target sizes you will attain full depth relative to ground noise, others will be much fainter or barely recognizable, savvy operators will take full advantage of this.
The beauty of the Smooth type Timings are they allow the use of a Monoloop coil in noisy ground conditions which are by far the most powerful deep seeking coil option for all the Minelab MPS detectors, as mentioned above the Timings will in some cases provide full depth on some targets compared to the Normal Timings and less depth on others. However when it’s all weighed up the depth reduction in a lot of cases is still much less than the trade off of going to a Double-D coil, which has a depth reduction across the board on all target sizes due to the design. Getting to know what your detector is telling you is paramount in the learning process (I try to learn something new about my detector every time I go out).
To sum up, I always prefer a round Monoloop coil to a Double-D coil for outright depth regardless of the Timings, however there’re some instances where a Normal type Timing in combination with either a Monoloop or Double-D will provide the greatest outright depth dependant on target size, depth and ground mineralisation present.
Hope this helps,
Bewteen your above response and watching your great new video "Unwrapping the GPX 5000" multiple times, I think I hear what you are saying. The enemy to hearing targets is ground noise produced by mineralization.
I suppose you said it best saying "match the Timing/Coil to the mineralization" at hand. Experimenting is key.
Thanks Again,
Mark