QED in wet ground.

Had an interesting experience today that some of you folk are gonna just love (not).
An American visitor from California who posts on the Detector Prospector forum and who has been detecting in the Golden Triangle area for over a week joined Adam (Northeast) and myself at the Coiltek test site on Lucknow lead. Adam has recently become a QED owner, and has had experience with the GPZ7000, which Mitchel, our American friend brought with him from the USA and has been using here. Adam wanted to see how the QED tested against the GPX which I brought along, and the GPZ of Mitchel's.
The test site was wet and unlike conditions when I have tested there before. The criteria was that each machine and coil combination had to be tuned for viable use in the area and not tweaked up to get a response purely over the target. The GPX was a bit of a disappointment, regardless of settings and coil combinations, only giving a 'dig me' response on two targets. The smallest, and the second largest. The GPZ gave a good response on the four smaller targets, but nothing on the largest and deepest target. (5ozs of lead.) 14" coil only as we did not have a 19" coil, but previous testing with the 19" coil was disappointing. The QED had tested here in dry conditions with the 11" Elite giving good responses on all 5 targets, but I had neglected to bring such coil with me so testing was done firstly with the Nuggetfinder 20" coil which not only gave a good response on the largest and deepest target but also gave a definite response on the smallest target. The in between targets were inaudible. We then tried the QED with the Elite 9" coil and got a response on 3 of the 5 targets, picking up the deep target that the GPZ could not, regardless of trying many settings that were not really suitable to general use.
Wolf from Coiltek happened to be there doing an instruction course, and tried the SDC on the test pad, but it could not pick up any of the targets. He said they were all too deep for an SDC but maintained that in shallow ground for small targets the SDC was tops. I do not dispute that.
An interesting test with reliable witnesses. Make of it what you will.

Sounds like the QED coupled to a fitness for purpose size/type coil, can more than hold its own over moist/wet ground conditions, against the other 3 detectors Reg.
All or any form of air testing done over any given size/type conductive target, should always be done knowing that the detector/coil combo can comfortably work the same section of ground one intends doing an air test in/over. What I'd like to know before throwing my two bobs worth in, is at what depth/type of ground (mineralization wise) was the 5oz slug of lead buried at?

Cheers Kon.

Kon, the Coiltek test site is on the edge of a shallow lead and is in what I would judge to be old ground (turned over) The ground is very changeable with ground balance not steady but varying from virgin ground to worked, over a space of a few meters. I have tested on this ground before under dry conditions, and the difference when wet is quite profound.
What this has proved to me is that different detectors and coils perform at varying rates of efficiency under wet conditions, but all the ones we tested had one thing in common, being less than perfect performers in wet ground.
The QED did not like some of the smaller targets except for the smallest, but shone when tested over the largest, where the GPZ had no trouble with all targets except the largest and deepest. The GPX was very marginal overall, and the SDC did not pick up any of the targets.
The testing results were unexpected to say the least, and if there was anything to be learned it may be that in wet conditions some machines could be left in the car. It appears that there is not just one detector to handle all conditions.

Can't say I don't agree with your test results there Reg. From past experiences, the difference from saturated wet ground, to swinging over the same section of ground dry, have been found to be more than profound to say the least. The drowning out of signal response by mineralization noise due to the ground being saturated with water, I believe to be a major contributor/factor.
I also agree as to the depth capabilities of the GPZ 7000 on larger conductive targets, for some time back in a section of mineralized ground up around Avoca, I buried a 4 X 4 inch, solid block of highly conductive aluminium at 37 inches deep, only to lose signal response over that 2.4kg block of aluminium at a measured 34 inches high/deep. The settings used were General/Difficult gain 11. (ground balanced to handle/prospect the surrounding ground conditions, using the standard 14x13 inch GPZ coil).
It mattered not whether in Xtra Deep or High Yield, for I could not pick up a signal response past the 34 inch mark. I might have to go back there some time, for the block of aluminium is still buried there (that is if no one to date happened to stumble over it & dug it up believing its a whopper slug of gold )  to see what the difference would be under wet conditions.

Cheers Kon.

Howard Rockey has advised me that the best results obtained at the Coiltek test site were with the 11" Coiltek Elite coil. However that was when the site was dry, and results could be different under current conditions.

https://www.youtube.com/watch?v=szulknsY0mU&t=2s

All of my detectors, PI & VLF achieve better depth in fresh water wet ground than in the dry. So what is the prob with yer GPXs?

Adrian, as usual you are just trying to be obtuse. There is (was) nothing wrong with any of the detectors used in the test at the Coiltek test site, including the SDC used by Wolf from Coiltek. I know there are those who insist that wet or moist ground gives better conductivity, however the general consensus is otherwise, and the tests held on Friday seem to bear this out. What I am unsure about is whether there is any advantage with very slightly moist ground over bone dry ground.
Having been to the test site on a number of occasions, there is no doubt in my mind that this particular ground when very wet presents problems with the detectors we were using. Whether this applies to all detectors, and all ground would require much more testing.

I don't have to try to be obtuse Reg, ut just comes naturally for me....(Mentally slow and emo insensitive)
I can only speak for the types of detectors that I have used....Very low all the way to high end GB VLFs and some pretty good PIs, not inc any of the GPX's.
It has been awhile since I have been to a gold field but the type of ground that I detect these days is pretty average Aussie ground that GBs at between 8 and 9 on a ground balance range of zero to 10 for most vlf type tectas.
The weak signal targets in my t.est patch come in quite clear when the ground is damp-ish to wet.
I wonder if the high pulse/speed rate of the GPXs has something to do with the sensitivity to wet ground?...Just guessing tho.

From all my past experiences Reg, not only that section of ground, but just about all sections of ground containing reasonably high mineralization, especially referring to pockets or small sections of ground containing such minerals. Pockets of high mineralization saturated with water, tend to exasperate or enhance ground noise, drowning out what positive signals could once be heard by detector/coil when dry.
Damp conditions or damp soil (cool to the touch) but not wet or saturated with water, have produced the greatest depths achievements (for me anyways) over any given positive metallic in ground target.  
As most detectorists know & would agree, during the peak sun heat of a hot summers day, mineralization tends to double in strength, acting like an invisible force-field or invisible barrier limiting/reducing a detector/coils in ground penetrating effects, over positive targets. This is why during the early morning hrs  or just before sundown, that mineralization tends to disperse or quiet itself down as the temperatures drop, creating not only a more stable, quieter running detector/coil, but also achieving greater depths over in-ground positive targets, that otherwise could/would not be heard before.
Some might argue with this theory & say you're achieving the same depth over positive targets due to the drop in mineralization levels, making targets now audible, but then how can I explain or justify a gram of solid gold, found at say 10 inches depth in quiet ground, as to a similar in size/proportion slug of gold, found or barely heard, using the same detector settings/coil, at half that depth.
To my knowledge, all metal detectors PI or VLF, suffer to some degree over gold bearing ground, that is saturated with water & if they happen to run quietly smooth under those same saturated ground conditions, I would check/hate to see, the depths they're now capable of achieving.

Cheers Kon.

You have summed it up pretty well Kon, and reflect my thoughts and experience. What percentages of performance differences there would be between detectors, ground types, temperature, water saturation, and even radiation, are up for speculation.
What was not tested, and on reflection should have been, was what difference the use of DD coils may have made to the GPX performance, which was surprisingly dismal compared to the QED and the GPZ. It would also have been interesting to see what difference a Russian coil would have made to the results with the GPZ on the larger and deeper target.
I realize that the accusation can be made that this type of testing is far from conclusive, and I agree, however, it does serve a purpose in that it shows where there are restrictions in even the best detector performance.
The difference between the Coiltek test site and others set up in the Central Victorian area is that the Coiltek site is in disturbed, turned over ground, where rainfall can most likely penetrate deep into the test area. The lead targets were planted into this environment vertically, unlike for example the site near Laanecoorie, where holes at various levels have been bored horizontally into virgin ground from a washed out gully. Targets can be slid into the holes on the end of a pole of some non conductive material. Various target sizes and different metals can therefore be tested. I would speculate that this site may well yield quite different results to the Maryborough test site as the water would be less likely to penetrate to the same depth, and the soil composition less variable and disturbed.
Obviously much more testing would reveal more conclusive results.

This might help understand why thermally heated metalic rocks introduce a bit more ground noise to your detector.
Off course you wouldn't want to be an "obtuse" person if you want to understand this little burst of info.

https://www.doitpoms.ac.uk/tlplib/thermal_electrical/printall.php

https://www.quora.com/Why-does-electrical-conductivity-of-metal-decreases-with-the-rise-in-temperature-while-that-of-semi-conductor-increases

This will give you a clue as to how wet ground effects eddy current production.

https://www.lsuagcenter.com/Nr/Rdonlyres/E57e82a0-3b99-4dee-99b5-Cf2ad7c43aef/77101/Pub3185whatissoilelectricalconductivityhighres.Pdf

Yeah, very helpful Adrian. Would you happen to have an English language version?

Kon61gold wrote: "Damp conditions or damp soil (cool to the touch) but not wet or saturated with water, have produced the greatest depths achievements (for me anyways) over any given positive metallic in ground target."  
"Some might argue with this theory"
Cheers Kon.

It's not a theory Kon, it's a fact. Heating any soil or rock that possesses magnetic viscosity (the ENEMY) will exponentially increase this viscosity response, this opposes the magnetic field from your coil reaching the target and what little is generated by the target reaching your coil. The worst scenario is when the ground surface is scorching hot from the sun while the lower strata just beneath it is cool from recent rain.

When the whole earth beneath your coil is cool and a homogenous temperature you will achieve the greatest depth.
I know from experience on a number of occasions that at the end of a hot day with a heavy late afternoon shower I have had really good success, with targets popping up all over the show, often on what was considered worked out ground.

Cheers
Kev.

Like Reg, thanks for putting it down in layman's terms Kev, so that I & many others on here, who have little knowledge/understanding in the sciences, can begin to understand it. Understanding ones detector/coil capabilities, coupled to the type of ground one intends on detecting over, is practically 80% there, towards a successful gold detecting trip. Any percentage left over (in my opinion) depends on luck.
Adrian, although there's alot to digest (scientific wise), much appreciate your input on the above matters.

Cheers gents, Kon.

Reg Wilson wrote:Yeah, very helpful Adrian. Would you happen to have an English language version?

Ut's English when I read ut....Maybe the translator is in my head.