My Thursday X-coil Iffy

[Norvic]

 

OK, as one who normally doesn`t post photos, but in this thread to support my fellow early bird JW and to encourage MN in breaking his X coil virginity. The coil with the gold on was my first X coil (15) and that is its return in a short couple of weeks with that coil, photos were taken in July 2019. Initially I went to an isolated patch that was found with the Z 14 and flogged by two Z operators with both ML 14 & 19, that patch I named Bogenes as it is a very variable hot piece of ground and in clean up Bogenes scored extra pieces. Running the X15 on the Z over this ground on its first outing up high where the reef shed on very shallow ground the 15X scored no hits but moving down the slope into deeper ground on this first outing with the 15X I picked up numerous pieces all at depth that 2 very experienced Z 14 & 19 operators had missed and at even more amazing depths then the Z14 &19.

To add to this story when both the 10" & 12" X coils came I run them over that shallow bony piece of "Bogenes" working carefully both these coils scored. Further I run my modded SDC (named "The Placebo" after modding ) both the original 8" and Coilteks 11" on this machine scored. As you can see from the smelt of the 15X results, my initial X finds paid for my X coils and enough left over for good wages.

MN I cannot as yet comment on my 10x15 as in its first & only outing so far it did not score, but I can sure say without a doubt the 15, 10 & 12 Xs are producers. Like JW I have not since my first X coil seen any need for either the 14 or 19ML coils but I keep both as neither owe me anything and I have another coil cable chip end I can soon make into a patch lead should my current one fail.

[Norvic]

9 minutes ago, phrunt said:

That's not fair!  

Actually it is very fair in reality, though I know you are commenting good heartedly "tongue in cheek", tis fair particularly that I support my fellow DPer JW who has shown us all the Xing time he has had. Plus of coz to spur MN on as it is his thread we are sort of poaching on.

[jrbeatty]

Good result Norvic. Reinforces everything positive already stated about X Coils versus standard ?

[Jonathan Porter]

At no point did I say the coils do not find gold, just that I found it amusing one of the suggested reasons for not finding any with the new beaut latest and greatest was that maybe the ground had been thrashed. That’s the whole point of the coil isn’t it? To try and replicate others successes on thrashed spots that have given up the ghost with the shoddy ML GPZ14 coil!! Isn’t that the constant mantra on the forum these days when the unmentionable coil subject comes up? BTW I was not having a go at the OP, far from it.

Here are a few pics of the successes I’ve had with one of my X coils in the right environments, I didn’t keep a tally but it was well in the multiples of ounces in only a few weeks work. 

and here are a few pics of the gold I found the same trip with the GPZ14 because the other area I was in was not conducive to the X coil.

 

In reply to mn90403, I was not being negative towards the effort you were putting in to get gold with your new equipment. It’s good to see enthusiasm and drive and I have to wonder why my post has been taken that way.

To answer your question 

Quote

So, my question to you would be this.  What coil and detector combination have you used that would find more gold than any other?  What I mean is, if you went over completely virgin ground where all of the nuggets and trash were still in place, is the 7000/14 the best that has ever been?  What are the next ones behind it?

IMHO the GPZ 7000 with GPZ14 coil to date has been the best detector coil combination I have ever used, the coil works in ALL environments, it punches incredibly deep on large gold and has incredible sensitivity to small gold at the same time.
 

Pic of 3 ouncer found with the standard GPZ14 coil at 2 1/2 feet in variable ground.

In closing, I‘ve seen lots of posts over the years about how a coil did Bala Bala blaa, but at the end of the day it’s the electronics that it’s hooked up to that is really doing all the heavy lifting. I posted because I felt an Oxymoron was quite funny and tried to put a serious tilt to the whys and wherefores of the motivators that drive us to keep trying our luck, it was in no way meant to throw a wet blanket on a fellow prospector having a red hot go.

JP

[fredmason]

Jonathan, I got your post...the X is supposed to find what other coils missed. In My friend, Mitchel’s case all he found was junk...that was missed.

Does that mean anything...yes, it means he has not found that invisible gold that is all over NZ and OZ...but, he will!

fred

[Jonathan Porter]

3 hours ago, fredmason said:

Jonathan, I got your post...the X is supposed to find what other coils missed. In My friend, Mitchel’s case all he found was junk...that was missed.

Does that mean anything...yes, it means he has not found that invisible gold that is all over NZ and OZ...but, he will!

fred

Fred my point actually was about the, to me, humorous comment that the ground Mitchel’s been going to is too thrashed. Kind of like saying “killed him dead”.? I think we can all say we’ve returned to patches that are thrashed and struggled to find anything even with totally new tech, as has been said the gold has to be there in the first place for it to be found. I’m sure Mitchel will persevere till he finds the right combination/location where everything lines up. Obviously the places he has visited thus far are not conducive to that yet.

I too have found myself caught up in an expectation that a combination that has blown my mind in one location will do the same for everyone else everywhere else (hence the above humour?) but sadly that just is not the case. There is enough of these unmentionables floating around now for more people to be coming forward with similar successes as has been constantly shown here, but as I have tried to show in my last post these successes do not happen everywhere, you have to be selective on the areas you spend time to take full advantage. In the case of these new coils the best locations are homogenous low X ground types, because of the extreme near to windings sensitivity of the spirals the full potential won’t be reached unless a combination of factors come into play. 

The types of locations to target are low mineralised bedrock areas with gold embedded within the cracks and fissures, or areas that have weathered sandstones or low mineral schists that leave a homogeneous talc like soil overlaying the gravels, this way you can keep the coil as close to the ground as possible and the saturation signal and general variability of the ground does not mask or swamp out the deeper missed targets. I did exactly that last year with my 17” round and had an absolute ball.

The 17” round in the right conditions has better sensitivity to small gold and better depth than the GPZ14, put it into more variable mineralised areas and the sensitivity part evaporates very quickly but depth is still better than the GPZ14”. However if the X signal starts to become dominant and more especially if that X signal is variable in combination to strongly magnetic surface particles then the added noise negates the advantage so I then revert back to the GPZ14.

So far the people claiming to have had the most success are the ones working the areas that provide the coils with the right soil types to take advantage of that success. I look forward to reading more about Mitchel’s exploits as he goes about the task of revisiting favourite old haunts.

JP

[Gold Catcher]

This is a great educational read, tells you all about X/R signals and why mineralized soils (where usually most of the gold is) produces large X-signals.

METAL DETECTOR BASICS AND THEORY

(Bruce Candy)

Just google it to get the pdf link, it's on the minelab homepage

 

Some exerts:

"As with most introductions, the above brief description is over-simplifi ed. The signal induced in the receive coil, by the magnetic fi eld of the eddy current, can be thought of as made up of two simultaneous components, not just an altered component:
• One component is the same shape as the transmit signal. This is called the reactive signal (“X”). Because it is the same
shape as the transmit field, the signal, by definition, responds immediately to what ever the transmit signal is doing.
• When this X component is subtracted from the eddy current induced signal in the receive coil, the shape of the remaining
signal depends only upon the history of the transmitted field, and not the instantaneous value. This signal is called the
resistive or loss component (“R”)."

 

"Unfortunately, soils are magnetisable and thus also detected by metal detectors and cause signals which interfere with metal target signals. The degree of the magnetic properties of soils varies considerably. This magnetic property of soil is usually called “mineralisation.” The mineralisation produces almost entirely X and only a small fraction of R signals. The R and the X signals of a deep metal target are typically much less than the soil X signal, so obviously it is better to use the R signal to locate metal targets, rather than X."

"USA goldfields are typically different from Australian goldfields:
• The USA soils are mostly mildly mineralised but in some areas may contain either nearly pure magnetite black sands or rocks, which
are problematic for metal detectors as they have very high X components (strongly attracted to magnets).
• Australian gold fields have highly mineralised soils, but very few black sands or rocks that contain nearly pure X magnetite. The
magnetic materials are in the forms of magnetite-rich small pebbles and rock coatings, clays and general “sandy” soils. These all
contain magnetic materials that produce high levels of X signals as well as R. The ratio of X and R is random, and the R component
arises from extremely small magnetic particles called superparamagnetic materials, which are discussed below."

"As stated earlier, mineralisation produces a large X component and a much smaller R component. Unfortunately X and R are unrelated and their relationship varies randomly from one location to the next. Salty soils produce R signals from the mineralisation, as well as from the salt conductivity. However, most goldfields do not have salty soils, and in these non-salty soils, the soil R/X ranges from about 0.5% to some extreme “hot rocks” with R/X about 5%. However, the nearly pure magnetite black sands and rocks exhibit very low values of R/X; <0.1%. In very highly mineralised soils, such as Australian goldfields, median soil R/X is between 0.5% and 1%, but this ratio varies from location to location. Some non-salty non-goldfield soils have R/X as high as about 10%."

 

[Gold Catcher]

1 hour ago, Jonathan Porter said:

However if the X signal starts to become dominant and more especially if that X signal is variable in combination to strongly magnetic surface particles then the added noise negates the advantage so I then revert back to the GPZ14.

This relates to point that Bruce Candy made (see above post). In my uninitiated view, this means that for grounds with large X-signal the Xcoils may struggle

[Steve Herschbach]

Could also be you are being a tad sensitive and defensive JW.