Are we focusing too much on small nuggets?

Jefgold wrote:In recent years there has been a big swing to the new detectors likethe 5000 and the 4500 which are far more sensitive and better balanced. When you link them to a mono coil particulary a small one, you can't beat them particularly for small nuggets. This has been proven especially in the west and in Victoria.

But is this at the expense of the larger nuggests we used to find with the SD2000 series? Are we concentrating too much with what the dealers are telling us rather than going back to making full use of the machines? Is Enhance any good for DD coils and what is the best setting for depth and finding large nuggets?

Maybe by using these new machines in their basic settings with DD coils we may get better results. Should we think outside the square they have given us - food for thought?

Jeff

However how do we compare the depth of a 2100 and a 4500?

stoppsy wrote:welcom whylee, you will love this hobby it's great. what set up do you have?... anyway i'm going to try my detector in deep with the 14" N/F for a good part off the day next time i'm out, just as long as my arm holds up. i'll see how i go.
cheers
stoppsy

nero_design wrote:
Yes, many people are out spending too much time with all the wrong settings (and often the wrong coils) whilst seeking out deeper targets. And to answer your open-ended question regarding Double-D coils, I heartily agree that they are often the perfect coil for the job. You can walk into any well stocked detecting store today and look at all the monoloop coils there on the shelves yet there's just a handful of DD coils in that selection (There's a perfectly good explanation for that, Monoloop coils have more performance even when the Smooth class of timings are used). You can count them on one hand in most instances. Everyone buying a new GPX detector is running the standard monoloop on it OR they buy a larger monoloop to better their chances of larger, deeper targets. (This comment kind of answers your own question don't you think?). As for dealers being the cause of such migration, I'd say that many dealers probably do steer people towards the larger monoloops ...and so do many well-intentioned detecting partners - all of whom are under the belief (be it true or false) that monoloops are the way to go. (Its true Marco, you should get with the program, the dealers are pushing what's unique about the detector). I don't believe that Monos should be the first choice of coil for a new detectorist and I certainly believe that if you are after larger nuggets at greater depth, then a DD gives you more clarity and stability when it comes to smoother operation on highly mineralized ground. (Not true, the instant you put on a DD coil you suffer from a depth reduction on all target sizes straight away (except for those very close to the coil) ). If you like going after smaller nuggets, then use any coil under 15" and you ought to clean up well with the very sensitive monos out there at the moment. (DD coils are very good at this too if used correctly). But for those looking for larger, deeper nuggets of considerable size, I'd be more inclined to consider using a LARGE DD coil in many instances (though not all), myself unless the ground is quiet and more benign. (The only advantage in using a DD coil is the ability to also use discrimination and the Normal timings in hottish soils which can offer full depth of the coil if the conditions allow). Obviously if working a patch you would spend quite a bit of time with more than one type and size of coil. I gave up scratching for little nuggets a while ago and now generaly use larger coils to seek out larger nuggets at depth. I depends where I am detecting though. I do use monoloops but certainly not all the time. And the very same argument applied to the GPX-4500 can also be applied to the newer GPX-5000: Since these new machines run quietly on monos, everyone is running monos on the new machines. (Obviously) The disadvantage here is that they rarely set their detectors to deeper settings because they are reproducing the settings they see other people using... which of course are designed to maximize their gold haul overall rather than project deeper for the larger, deeper bits that might have been missed before by others. (This might be a good opportunity for you to let us know what those "Deeper settings" are?)


My wife using an 18" Monoloop on the GPX-5000. This ground almost had me swapping to a DD coil. The only reason we didn't was because the area had been previously detected and we only had a standard 11" DD on hand. I felt that the benefit for us was therefore with the coil we had that offered the greatest depth. As it was, the targets were not all that deep.


I suggested last year (or perhaps the year before?) that the lack of DD use on the GPX-4500 was probably the main contributing factor for fewer large nuggets being reported in recent years. Clearly, nobody told the Sudanese this because they were tearing up monstrous nuggets just as fast as they could find them last year.(All with Monoloop coils, that should tell you something Marco). I also noted that J.Foster's belief in DD coils (something a number of people online disagreed with (That would be me)) back in the days of the GP series made plenty of sense when it came to detecting through multiple layers of mineral deposits into old wash to recover a signal from below the wash from a larger nugget. (I consider this information to be incorrect) I know not everyone cares for this opinion but allow it to pass this time without argument for the sake of my response to Jeff's question. (Oops I was supposed to allow that to pass, sorry can't do that because it's rubbish even when offered hypothetically) The monoloops were at a disadvantage when used on older machines because they ran mono coils noisily. (That would be because of the timings being used and the ground being detected in) Similarly, new detectors like the GPX series can now run those same type of 'noisy' monoloops very quietly these days. (Thats because of the timings, your contradicting yourself Marco; readers see a pattern here?) So smaller gold is still found with the advantage with monos. They also go deeper than comparatively sized DD coils. But they are indeed noisier than DD coils - which are quieter and more stable in mineralized soils than monos. (Crikey your getting me all confused with this line of logic) Therefore DD coils have the potential to return a signal through highly mineralized soil that might be missed with any other coil. (Only if the timings allow for it, dependent on target, ground and other factors, but then look at all the gold the DD coils missed) The quieter you can run your machine, the better the chances of hearing a fainter (deeper) target against the threshold and against any interference. (Thats the whole point of the Smooth Class of timings.) One of the first times I used a GPX saw me swapping my monoloop for the standard Double-D due to the mineralization where I was. The difference was incredible in that spot. (Sounds like it was either Conductive ground or you did not have your detector set up properly.)

Since gold nuggets are most commonly found in the more highly mineralized soils, then it makes sense to me that DD coils (being quieter on mineralized soils) - especially larger ones - would be the best to use for the deepest, faintest, larger targets. (Quieter than what? A Mono in Normal timings? or a Mono in Enhance for example?) Whilst this would be considered by some to be simply hearsay because I was not there to witness the original conversation, I was told last week that Minelab's 'chief scientist' once advised an acquaintance of mine that the 15x12" Minelab DD coils was (at the time) the best coil to use. (Gossip I would say, but nothing wrong with a bit of name dropping, a friend of a friend of a friend of mine said.....) Please note that this was before the GPX was released. (Thanks for the clarification, would hate to see people mislead) He seemed to feel that anything larger was likely to be a problem for the detectorist. (larger equals heavier perhaps) Of course, Minelab make a larger coil (the two 18" coils from the Commander series) so obviously they serve a purpose and can benefit the more serious detectorist who needs a deeper seeking coil. No doubt the more recent GPX series can handle these larger coils better than the earlier machines.

Using the wrong coil and detector settings on the wrong depth of ground might also be a contributing factor. Not many detectorists take the time to see just how deep the soil is they are detecting on or they can't read the ground. If the soils is too deep and of the wrong composition to hold larger gold closer to the surface, (generally gold is found on or near bedrock ) then the detectorists may not be able to get close enough to the bedrock to pick up on the signal from any targets resting there. (Use a larger coil or move to shallower ground ) Interference and large coils on highly mineralized ground is a recipe for more noise and less audible target responses. (True to a certain extent, but interference is found around quiet ground too, more noise no matter where you're detecting is detrimental) With VERY few exceptions, almost all the big nuggets that came up in the last few years in Australia seem to have been won with Double-D coils.(Nonsense) When J. Foster wrote his article for GG&T magazine, he noted that every large nugget on record that had been found in Australia that year was located with a DD coil. (How could Jim possibly know that, around that time I personally found numerous large nuggets (up to 80+ ounces) at depth in mineralised soils with Monoloop coils and have always done so on decent sized gold my whole detecting career) By comparison, many of the coils being used today are 18" or larger and they're almost always large monoloops. (Huh I thought you said earlier on small coils are mainly used these days?)

Everyone buying a new GPX detector is running the standard monoloop on it

One of the new Coiltek 22" Monoloop Goldstalker coils (with my hand for scale) - designed for use on the GPX series detectors. Not exactly a little coil.


Someone asked a similar question on a US based site to which I submitted the following reply (this is a trimmed excerpt from that reply):

"....I think the DD coil is often overlooked entirely by too many people and perhaps for all the wrong reasons. I believe the Monoloops are certainly more sensitive to very small nuggets but most of the little ones being found by locals where I detect are small enough that I'd rather pan for them in the creek at that size. (problem is the bulk of these little nuggets are laying scattered around on the slopes where panning is not an option and in a lot of cases easily found and a lot of fun to boot). The DD coil is stable and quiet in really mineralized ground. Much more so than the monoloops. ..... (and it also has a major depth reduction on all target sizes, hence the Smooth Class of timings for Monoloop coil use)

.... It's true that the DD coil has less depth (due to the send-receive wires being half the diameter of the coil) (they also have more windings on the receive so are more sensitive to shallow surface targets compared to a similar sized Monoloop in conventional timings) so for my needs it's better to obtain a slightly larger DD coil like the 15x12 or larger unless working on shallow soil or for small specimens. I think that because the DD coils are quieter and less prone to mineral related ground noise and external interference, then they have the ability to offer an edge over the monoloop coils in many circumstances and conditions. (Nonsense) If you are using a quiet setup with a DD coil, then you have a much better chance of hearing the target over a setup that is noisy. (Obviously) I'd personally prefer to use a VERY large DD coil over a medium sized monoloop myself when looking for larger gold at depth. However, I would probably not bother so much on shallow ground with a DD coil when there's a range of decent monoloop coils on the market today that would pick up on all the smaller gold better than a DD closer to the bedrock.... (Shallow ground in the majority of Australian Gold Fields and what I saw when I was in the US are generally heavily mineralised, this ground type is very conducive to Monoloop coils and Smooth type timings.)

I am hoping the main coil makers will get around to producing some new DD coils for the newest GPX machines. They had some models that were being tested last year in the US but I believe there may have been issues which prevented them from reaching market (is this gossip again, or fact?). Many of the most spectacular nuggets I've seen come out of the ground in the last few years came from DD coils on older machines and even DD coils on newer GPX detectors. I have no doubt the monos can pull up a lot of gold but there's been some spectacular nuggets found with those DD coils. (please show us some examples) I'm actually a little amused to see how little coverage there is on the subject online. I'd personally like to get a larger-than-18" coil in the Double-D configuration. Having sampled the soil in 3/4s of my state, I find much of it to be just too noisy with the Monoloop to feel confident that I'm not leaving gold behind. Especially larger, deeper gold. I'd like a brand new DD coil designed especially to run on the GPX-4500 and the GPX-5000." (There are four of them from Minelab alone, 12" ellip Commander DD, 11" round Commander DD, 15 x 12" Commander DD and lastly the 18" round Commander DD.)

However how do we compare the depth of a 2100 and a 4500?

Some say they go so similar depths. However the more recent detectors are not only more sensitive, but they are also more capable of filtering out noise from the ground, enabling the user to hear much more that was otherwise garbled or masked. (But Marco the very thing that makes the GPX series so incredible is what your expose seems to be trying to avoid, not the filters as you describe but the timings or as Phil Beck remarked in my interview with him on Minelabs website, the Receive Waitings!!Minelab Web Site) That's one of the very best reasons to consider a modern detector over an older model. If you're serious about finding gold that others have missed compared to seeking out gold that you might 'accidentally' find. (What's the point if you are only going to use a DD coil in Normal type timings? You may as well use a GP 3500!)



If we look at the comparisons shown on the original Minelab SD2100 brochure (not sure how many people have seen this in recent years!), it's clear that there's a 15% to 30% stated depth increase on the more recent model compared to the SD2000. However, is this a difference showing actual depth or is it simply the ability of the newer SD2100 to receive and hear signals that were otherwise masked by other factors on the earlier model? I don't know. Perhaps someone who knows the answer can contribute here.

_________________
"A man who carries a cat by the tail learns something he can learn in no other way."
MARK TWAIN


(The depth claims were on targets that were missed or ignored or barely heard on the SD2000, so in some cases there was a 15% to 30% improvement on targets. Depth is always a difficult thing to make assertions about because there are so many factors involved that can impact on the outcome, the SD2100 produced a lot of gold missed by the SD2000, some of it was considerable in size and some was in the gram category. If the GP 3500 missed a piece of gold either with a Monoloop or DD coil in hot ground but a GPX 5000 came along and scored that target at 14 inches does that suggest a massive depth increase over the 3500? In more conducive circumstances the 3500 would have romped the target in but the same can be said for a VLF detector, so putting a percentage point figure on depth is very difficult to do.)

nero_design wrote:JP, your failure to comprehend the purpose of this thread does not surprise me. And since I know that you know better (considering the numerous errors concerning your corrections), let me remind you again that there are many, many people out there who find much of your contributed information to be ego-driven nonsense. I'm not so much concerned about what other people think about me. Never have been. But for your own sad sake, please think (yet again) before you post online corrections. You could have done so several ways other than the method you chose. And the method you used makes you like like a jerk. Again, only you can fix that.