jasong

I thought it made sense too Andy, but... I was literally just typing up a response about an experiment I did to see if it made a little more sense in physical observations, I'll still post it but I apologize in advance for it going kinda off the rails and certainly no one needs to read this to understand their GPZ. "On a mildly tangential note, I decided to do a crude experiment after reading up on superparamagnetism via Chet's post. I have some ferrofluid which will show magnetic interactions well under the field intensitities which something like magnetite will physically saturate. It is also superparagmagnetic, technically speaking. So I put a plastic container full of ferrofluid on top of my GPZ coil expecting to see some kind of minor oscillations or something. But no result. Probably has something to do with the mag field alternating or something with ZVT that I don't understand where things cancel each other out, or maybe the GPZ works off EM radiation and not mag field interactions, I really have no idea. But now I'm wondering how we can even be saturating minerals under the coil at all since the mag field of the TX coil seems to be relatively small, certainly not in the 1+ tesla range. I'm sure I'm mixing something up here with alternating mag fields and EM radiation vs permanent fields and whatnot. But are we even really emitting a mag field powerful enough to saturate ferrous minerals is what I'm wondering? And if not, is the physical definition of saturation not what Minelab is talking about? Further, saturation point implies very little mag field change in the ferrite/ferrous material with increased TX strength, which should be a good thing. Less ground noise. So why do we want to avoid it? Would it be best to just saturate the crap out of the ground since everything past that point generates very little noise? Like the B curve for magnetite is almost flat after saturation even if you quadruple the external mag field, whereas up to that point the saturation effects B exponentially... Just. So. Many. Questions. Some major definitions or pieces of data are missing otherwise this wouldn't be so confusing to me."

I've seen you say this often. If this is true, how is salt affecting the ferrite balance? Salt is not a ferrite. Salt is a conductor, like gold. So, will gold and other conductors affect the X balance too if salt does? Also, what I can't wrap my head around is this: 1.) Ferrite is X. 2.) X is in our soils, thus ferrite is also in our soils. 3.) Semi auto tracks to the yellow ferrite presumably because that component isn't in our soils, and we now keep X constant to the ferrite and not our local changing soils. 4.) X continues to change in our soils but our X value in our detector stays steady. IE: not tracking the ferrite in the ground anymore So, how is that not causing noise as the soil's X component changes yet our detector is staying tracked to the ferrite? Why not just keep the detector always configured to the ferrite by adding some kind of offset into the firmware if it needs the ferrite data and not our local X soil data?

Rob, did you try Semi Auto in the same places that you ran Auto in the past without noticing much difference or were they different spots this time? Can you elaborate on the ways you noticed Semi Auto method working better this time? Were you in a place with some amount of mineralization or was it fairly mild? Your general part of AZ is so variable in the intensity of ground mineralization that it's hard for me to guess, I've seen the gamut from requiring Difficult at 10 sensitivity to being able to do Normal full bore, all within 5 miles.

I've read it inside and out, and every post I can find. A lot of stuff seems to conflict to the point I don't feel I can even ask a proper question first anymore until we get some basic defintions of what these things are we are talking about and why/when exactly we need to be using certain tracking modes and the ferrite. The only reason I'm looking more into it and asking is because JP's mentioning all the stuff. Otherwise, I was pretty content just staying in auto tracking and never using the ferrite at all. But lately we were told that we are unobservant operators if we see no need to use the ferrite and we can't tell the ferrite balance is going out. I have not observed Auto ever failing to balance within a second or two on my soils except in a few instances, and in those instance the QT button tracked it back within a few seconds of moving the coil around. I suspect that some of this applies more to hotter soils in Australia than in many places in the US (other than perhaps South and Central AZ). But it would be good to get some clarification on that too if that is the case. That brings up another question I've had - why do we even need to use the ferrite at all if there is little to no ferrite component in our soils? I have 20 or 30 questions right now, but I'm not even sure if they are real questions since I don't have the underlying fundamental defintion of what variables represent to even know if it should be asked or not. For instance - why do I even need to use the ferrite in Auto if the ferrite component is actively tracking?

I would really like to hear what JP says too since I'm getting really confused with what exactly X and G entail also, and there seems to be conflicting bits of information all over the place in various posts. From a physics standpoint: saturation should be the point on the magnetization curve where any permeable ferrous or ferrite mineral stops increasing the B field exponentially when an external mag field is applied, ie where all it's domains have already been aligned with the external magnetic field. Therefore, unless I am misunderstanding it, saturation is not a response itself, it just affects the X response as the ferrous or ferrite materials go in an out of saturation as the applied magnetic field from the GPZ changes. For sake of defintion (someone please correct this if not accurate) - ferrous and ferrite materials are natural occuring oxides of iron most commonly for our purposes. AKA - hot ground. But ferrites can be a lot of other things also that we don't encounter as commonly. That being the case, I am struggling to understand how salt affects the X balance and requires one to toss the ferrite down again since there are no ferrous or ferrite components in salt, but this has been said many times over as if it's understood somehow that salt will throw the X balance off. I cannot find a proper definition of what exactly G is tracking and it needs to be defined in order to understand this all I think. I asked a few times in the past... It doesn't appear to be anything scientific specifically that I can find, but something related to detectors so someone with knowledge of detector engineering would need to define it. I don't get if X is only ferrite and G includes non-ferrite permeable materials like magnetites, pyrites, etc. Or if X encompasses all ferrite/ferrous materials and G only includes the conductive response of the ground? Or...?

I'm still unclear on why auto tracking is not sufficient on the GPZ, especially for milder soils here in the US. There was discussion in 2015 how it was much faster and more sophisticated than the GPX auto tracker and so should be used, but now it's somehow too slow again after semi auto came out..? My experience has been it tracks fine in my ground and I simply pull the QT trigger if it's taking more than a second or two to catch up to me. I detect pretty fast and it's never slowed me down. I thought the GPZ was supposed to "remember" the ferrite in any tracking mode? If not, then why use the ferrite at all in auto at all since it'll just be tracked back out a few minutes later? Seems to me Semi Auto is best used in places with a lot of ferrite component in the ground - like Australia. There aren't a lot of places like that here in the US. Or potentially in places with a lot of salt since JP has said a number of times that salt throws X balance off, but that confuses me too since it looks like salt should be part of the G component of tracking where Semi Auto is the same as Auto anyways and there has never been much talk or definition about G or how exactly salt messes with X balance without being part of X...

That sounds like a pretty dang good guess about how the X Coils are achieving some higher sensitivity, nice catch. Good idea, and pretty easy to try. *Had a question here for you but I answered it myself Googling, so deleted.

And of further relevance, here is the Wiki post on the legality of decompilation of software even in the event Minelab didn't use open source and 100% of their firmware was their own creation under exclusive license. https://en.wikipedia.org/wiki/Decompiler#Legality Note the specific case they reference is one company decompiling another company's software locking mechanism. Almost exactly what is happening here. And the US case ruled that was legal. Seems to me there is a stronger case to make for the legality of circumventing the chip through software for a need of interoperability, than hardware. At least in the US or Europe, when it comes to laws and court precedents. A 3rd party company could definitely make this case in the US anyways.

I wouldn't be so sure Simon, I decided to look further into it and chase down an official Minelab EULA (those things we mindlessly click "ok" on when installing a new piece of software, for those less computer saavy amongst us) in order to figure out what sort of copywriting was involved and wether they sourced libraries or open source code that users have every right to edit. And I found this: https://www.minelab.com/opensource So, they might be using open source already to create their firmware in some form another. Or on second thought it could be the XChange software, or who knows. However, the GPZ 7000 link doesn't work for me. In fact their entire site is blocking every IP from my ISP for some reason so I can't actually open any link anywhere from Minelab right now. *note to Minelab: The link needs fixed, it's a part of the agreement for the code you have reused. But another thing I wanted to mention given the obvious fact the GPZ is manufactured in Asia - my buddy used to work in the video game industry and they would hire out a ton of programming from Asia and India, none of which they could enforce copywrite on for reasons that were never really explained to me. I'm not sure we know Minelab themselves even wrote all the firmware anyways, it could have been written in Asia without copywrite (or under GPL or similar), or if they only wrote parts then maybe some are editable. For instance, they may have used directly the library code right from the security chip manufacturer. And library code is generally covered under open source EULA's which mean it is editable. There is nothing wrong with talking about this stuff and figuring out what is right and wrong. Minelab watches these forums, they are welcome to let us know if we've misinterpreted something themselves too.

Heck yeah it does. Mineral shows and collectors are all about localities and records. I bet the largest nugget in AZ would go for 4x what the 2nd largest nugget would go for, even if they weighed similar. 1+oz nuggets today are usually exclusive access to land no one else can access. In the few cases that isn't true, it's usually just raw luck. From my observations of the ones I know about anyways.

That's no good to hear at all. I really hope you get something working. Is it giving the "coil not connected" error when you attach Dennis' stock Z14, or is it doing something else? I wish I could think of a helpful suggestion, all I can think is maybe reinstall the firmware? Or maybe a wire came loose in the ML connector going into the box (the one Simon posted a pic of with the ferrite) from all the connecting and disconnecting of coils?

Also digging through old posts, something I'm not able to find discussed is how Locate Patch and Salty Soil differ from audio smoothing like Low. As I posted extensively in 2015, Low Smoothing was the best way I found to deal with the extensive wet salt conditions there since it broadened the "smooshyness" enough that I could filter by ear an actual target and stay in HY/Normal as a result. Are the ground smoothing options in the GPZ patch update #2 simply just filters such as audio smoothing too, and if so is there a benefit to running say Salty Soil smoothing over Low Audio Smoothing? From what I'm reading online it sounds like the Ground Smoothing options do not actually change the ground balance itself at all, is that correct?

Ok thanks for the response. Yeah here in the us for the GPX, manual was the go to for sharp, sensitive extra, and normal too. I never met an experienced guy in the field who didn't run that way (the trainers I met in the field all said that's what they taught too), the idea being passed on forums at the time was that you could balance out a piece of gold in auto with the GPX in theory (something I tried many times and never succeeded at) and that manual balance got greater depth - something I was actually able to replicate to some degree on my own. Ok, previously I asked for a definition of X to understand the ferrite/ground balance thing better. Now I think I need to understand what G is better. I'm guessing G incorporates salt? What else is there other than saturable and salt signals that the ground balance works on? I'm trying to figure it out because it's the red line in the Minelab ground balance graphs, which seems to be the big difference between running in manual and semi or auto. I definitely do run too fast. But I do know how to slow down when I need to. But I also need to be able to go fast. I've never had people to show me patches, I have to find them all my own, and that means covering a ton of ground in the short amount of time I have away from work. It's absolutely essentially to my success. When I find a patch I slow down. I'm just trying to get a grasp on all this so when I go test these coils out I'm not messing something up by not being current on whatever the ground balance/ferrite procedure is now.

A catch-up question on GB and the ferrite since I had to stop detecting and go back to work full time before the update with Semi Auto was released: At the time, the general consensus was that running in Auto with the ferrite was preferable, reasoning being that the GPZ had a more sophisticated auto tracking program than the GPX series and it was no longer required to run in manual as we had been used to. It was only required to occasionally toss the ferrite down in auto to make sure it was still balanced to it with a QT pull to make it go faster. Is this no longer the case? I know in heavy salt areas before, it was almost impossible for me to stay in manual (I detect much faster than most and thus my patience for going that slow was limited) and auto tracking was much better. Will auto tracking no longer suffice to balance to the ferrite with salt present? Or does it still work fine but semi-auto just does a better job?

Not on this go around. I'll be going to NNV where my primary goal is to test the coils in heavy salt and to see how the smaller coils do in salt compared to the Z14. NNV is pretty well known for it's relative lack of saturable (ferric/ferrous/ferrite) components and it's preponderance of salt. I can ask a few people if they know of some bad saturable ground out there to test on though and give it a go. I've just never found any personally yet. The other issue would be that even if there is saturable ground, there is almost always a massive salt (conductive) signal present too so it's hard to seperate the two. Later this year I'll be going to AZ where I can take a run out to W to test where the ground is about the worst in the US, but I have two construction projects I'm working on that both need done before then. And unlike you, I'm not brave enough to go detect in 105 heat. I also ran into a mountain lion once out there, in plain daylight, and it still gives me jitters detecting in the dark as such (your bobcat encounter doesn't help either haha).

That's the assembly language I was seeing too - is ASM as far as it will decompile in your program too? Like is that the native language it was written in, or can it go up one more level to something like C? For instance, I used to program 8 bit MCU's and at first I had to do it all in ASM, but then Microchip released a C compiler that went from C to ASM. So here, can it be done in reverse one level higher up the abstraction ladder and the program takes a guess whatever higher level language it was written in? Or was it written in ASM originally? I'm utterly astounded it was that easy in any case.

The link to download that program doesn't work. I did however take a peek at the GPZ update in a random hex editor off Google. It does appear to be showing some sort of X86 assembly code instructions in a "disassembly" window when I click line by line. Am I mistaken in saying that means this GPZ firmware appears to be unecrypted then? It can't be that easy. There has got to be like some checksum to validate the update or something. Man, for my own good I hope I can't just decompile this into something easy like C++ because I'm going to fall down a rabbit hole of modding the crap out of my detector as far as the software will let me and eventually breaking something inside. But a thought occurs to me, even if we could disable the chip authentication, the connector containing the chip (and plugging into the GPZ) is still some weird non-standard larger connector. At least it's larger than the typical coil connector. So unless that connector is commercially available, a coil would still need cut.

Wait, the chip code is broadcasted unencrypted? Are you sure? Man, I'm gonna have to go download a firmware update and see if it's unencrypted out of curiosity. If not, I can just disable the chip authentication myself without cutting a cord. I seriously doubt they would have made that big of a mistake though. I'm not even sure how to go about figuring it out since a compiled program just looks like gibberish anyways in a text editor but anything can be found online I suppose.

That is my understanding too, that the 12" is the smallest coil they can fit the spiral windings into. My 10" is normal wound as well, and I believe the spiral wound coils are all supposed to say "spiral" on the face somewhere.

Thanks Aureous, I thought it had to be something like that based on the rather conspicuous lack of patent complaints regarding DOD during this discussion. So, the chip in fact protects no IP at all. What it protects is the ability for Minelab to regulate and profit from a coil aftermarket. An aftermarket which they never let materialize for reasons yet unknown. Well I'll say this: X Coils is about to create a lot of patched GPZ cables. So there might be a market for another coil maker now, and they won't even have to ask users to cut their cables, it will already be done. A patched GPZ can run any coil just like a GPX can. I'm guessing the spectre of that idea is moving along the approval process for whatever 3rd party coils are currently being held up on chip licensing for "standards" reasons.

The eagle has landed in the US... Thanks for the report Andy! That can be some gnarly ground down there, and perfect place to test any new piece of equipment. Was the 10" having trouble balancing over the ground in general, or only when you tried to balance over the ferrite on it?

I'm thinking my coils should be getting to customs in the US now, the tracking stopped in Moscow and got picked up by USPS but they haven't updated yet. Tomorrow is our independence day, which is a massive holiday here in the US and everything shuts down, so there will be a bit of a delay there and then the weekend. Might be as much as another 5 days before I get them, then gotta finish this construction project I'm on since the goldfields are 1000 miles away and can't take that much time off. So...lots more time left to talk I guess.

Right, and the chip still doesnt prevent counterfeiting in that case either because the software they will have to write will not have ML chip authentication in it and so any coil will work in a clone in theory. So again, the chip does not prevent counterfeiting in that case either. Guarantee the firmware is encrypted, so even if they wanted to copy it they couldnt. No Chinese manufacturer has ever made an exact clone of any Minelab machine, not even the ones without chip security. They dont even try near as I can tell. They just make something that looks like and kinda works like a Minelab product. And that is where Minelab is losing money. They sell clones in gold rush areas to clients who dont know how to tell the difference between a ML product and a clone in terms of functionality without any concern about how well the actually work. There is no need to make an exact copy and as I mentioned that is already being demonstrated by the existence of GPZ clones on the market already. The chip only prevents people from using a 3rd party coil on an authentic Minelab machine. There is no counterfeiting there unless Minelab wants to say any 3rd party use of the DOD design is counterfeiting or IP theft, and that subject was just covered here.

If one guy from Russia can make coils then I'm pretty sure the massive Chinese market could find a way to produce a coil too if that was the only stumbling block. Plenty of other 3rd party companies have also produced coils for the PI machines along with a ton of hobbyists. There is no way the Chinese couldnt do it too if they wanted, they probably just dont care since the counterfeit machines are generally garbage anyways so what's the point. But properly working coils arent magic voodoo that only Minelab can do properly, they are well within the realm of replication, even for hobbyists. Open up an 11" minelab commander and take a look at the very loose engineering inside them and you will see what I mean.

The chip doesnt prevent counterfeiting in any way I can determine. Chinese can still replicate the GPZ circuit board, they can still replicate the DOD design, and they can still replicate the physical design of the case. The chip prevents none of that. It's not like Chinese counterfeiters sell machines with genuine Minelab coils and thus are thwarted because they can't now with the GPZ. Presumably, further, a counterfeit machine wouldnt have the chip authentication so any coil could run on them. What the chip very effectively prevents is an aftermarket coil from being used without a licensing fee and company approval on a AUTHENTIC machine. Occams razor... it answers basically all the mysteries we've wondered about here. Unless someone can explain something I've missed regarding the chip doing anything to prevent Chinese counterfeiting. There are already counterfeit GPZs on the market so that would indicate it hasn't.