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Found 219 results

  1. I was reading the Australian Electronic Gold Prospecting Forum today and noticed a post about detector depth. I was wondering what others think about today's detectors compared to what was available 25 years ago. I read somewhere that (Woody) the guy that does mods to detectors thinks that for outright depth the sd2000 still goes the deepest. I wouldn't know as I've never owned a sd2000 or a gpz7000. Anyway, i found the comments at AEGPF interesting and wonder if anyone here has actually done a depth comparison between the zed and sd2000. Heres the snippet from AEGPF Quote from AEGPF: "The deepest Pi detector ever developed in my opinion was a prototype SD2000 that BC modified for the late Jim Stewart.BC slowed down the clock speed to give a very long pulse and made some other unknown changes to the circuit to cope with higher currents etc. At the time the SD2000 came out BC stated that it was at about 95% of the maximum potential depth that any handheld PI could ever achieve (and still pass emission standards). However, the deepest PI that has ever been made for gold was Corybns detector which detected a nugget of around 10oz? at 3 feet in depth in WA. Somewhere on the forum is a reference to it and I will try and find the link when I have time. "What is interesting is that the deepest nuggets ever detected by a Pi was by a detector used in the early 1980's in WA-Corbyn's wheeled detector! Pictures of it and the depths of some of nuggets he found with it can be seen in Mike Wattones book: Quest for gold.NO Pi detector today could match the depths Corby got on at least one nugget! (4cm nugget at over 36" in mineralized ground)"
  2. Editors Note: this thread split from http://www.detectorprospector.com/forum/topic/4335-the-reg-wilson-gold-album/ Nice stuff again... I'm having cardiac palpitations seeing all this gold....lol I wonder if you could tell us how your sled was rigged up. That looks nice for some open ground. Keep it coming....
  3. I am going through one of those periods where I load up a bit on new detectors and let it all sort out. Darwin's Survival Of The Fittest Detectors! This winter a number will not survive and will be looking for new home. This is the only way I have found that works for me. Detectors that serve a good purpose for me get used, others end up sitting. If they sit long enough, they are no longer needed. I have my nugget detecting fairly well sorted out. The GPZ 7000 gets used 90% of the time. I might pull out a VLF for a really trashy place, or for where the gold is smaller than the GPZ can hit (really small!). I do keep a Garrett ATX around to handle salt ground or oddball hot rocks the GPZ has trouble with but those situations have proven quite rare so far. So the GPZ is an obvious keeper. The ATX does double duty as my favorite water hunting machine so there is another. In the land of VLF however it is more complicated. I have this idea that a good selectable frequency detector might really do the trick in replacing two or more other models. The key there however is what I am going to go ahead and call "frequency spread" for lack of a better term. What do I mean by frequency spread? Simply put, the number of kHz between the lowest and highest frequency the detector can operate at. The lowest frequency is basically the "large item" frequency that more easily handles bad ground, and the high frequency is the "small item" frequency that tends to have more issues with mineralized ground or hot rocks. The high frequency option is critical for a person like me who nugget hunts. To really be able to replace machines like the 45 kHz Minelab Gold Monster 1000, 48 kHz White's GMT, 56 kHz Makro Gold Racer, or 71 kHz Fisher Gold Bug 2, the highest frequency option of the detector needs to be 30 kHz or higher or as close to that as is possible. Low frequencies in the single digits are great for coin hunting or very large gold nuggets in bad ground. Frequencies in the teens are a great compromise. Some examples: Nokta Impact 5 kHz, 14 kHz, and 20 kHz (15 kHz lowest to highest) XP DEUS Low Frequency Coil 4 kHz, 8 kHz, 12 kHz, and 18 kHz (14 kHz lowest to highest) Rutus Alter 4.4 kHz to 18 kHz in 0.2 kHz steps (13.6 kHz lowest to highest) White's V3i 2.5 kHz, 7.5 kHz, 22.5 kHz (20 kHz lowest to highest - bonus - runs in multifrequency mode) I am still waiting on the XP DEUS High Frequency Elliptical Coil 14 kHz, 30 kHz, and 81 kHz (67 khz lowest to highest). The XP HF 9" round running at 14 kHz, 30 khz, and 59 khz (45 kHz lowest to highest) is currently available. In theory the White's V3i is a real winner here but I have just never really taken to the V3i as a prospecting detector. I have to be honest and say that so far the Impact floats my boat more in that regard due to its more traditional approach to a detector interface, all metal modes, and ground balancing. The problem with all of them though is they just don't reach high enough to be used both as coin and jewelry machines and yet still be capable of retiring the high frequency nugget detectors. And that is why I am still patiently waiting for that XP Deus V4 high frequency elliptical coil. At 81 kHz (or 59 kHz in 9" round version) the Deus HF coils on paper at least could in theory make the high frequency nugget detectors redundant. I have to admit I still have doubts however. So far dedicated specifically tuned single frequency detectors have always won the day. For a lot of people however, a selectable frequency machine might prove to be "good enough". The downside with the Deus is that to get the deeper seeking lower frequency large coil option you have to wrap up quite a bit of money into two coils. The 9.5" elliptical is just not going to reach real deep due to its small size. I have the 11" round low frequency coil which can run as low as 4 kHz, so together the two coils make a pretty formidable package. The other machines however can run both much smaller and much larger coils, and at considerably less cost than what DEUS coils cost due to each one being a self contained metal detector. It may be that the XP HF 9" round running at 14 kHz, 30 khz, and 59 khz (45 kHz lowest to highest) is the better compromise option for most people than the 5.5" x 9.5" elliptical. The Impact does suit me as far as the way it functions and I like the excellent inexpensive coil selection. It is a shame it weighs twice as much as the DEUS, but that may actually be a benefit when it comes to balancing large coils. Overall at the moment I am really liking the Impact - I just wish the frequency had topped out higher. I really wanted more like 5 - 15 - 30 kHz. Going from 14 kHz to 20 kHz is not quite providing the extra "pop" on tiny gold I would like to see.
  4. I've been comparing numerous detectors as of late. I wonder about iron audio. I've been thinking about this,,based on what I see with some of my detectors,,,and am wondering if there would be some benefits. Iron volume as far as it being ON,,,does give distinct audio when the coil passes over detected ferrous material,,,but the being able to hear the iron volume tone(s) seems is tied to disc setting(s). Meaning run too high a disc setting,,,no iron tone whatsoever (with it selected). Could this be changed,,,where iron audio would be provided no matter the disc setting if a user wanted?? I could see at least some application,,where it might come in handy. For example hunting in a site with gobs of maybe lower conductive materials,,,just turn up the disc and hunt,,,,but operator might want to know if any areas seemed to be maybe moreso afflicted with iron and nails,,,,to maybe want to hunt this particualr area,,,using different strategy, detector settings,,,or even another coil or detector. I may be off base here,,,but would like to hear some folks thoughts on this. BTW,I do realize maybe notch could be used along with lower disc and do maybe the same thing.
  5. Here it is folks. Loaded with tuning tips! http://www.minelab.com/__files/f/254716/KBA%2024-1%20Basics%20of%20the%20GPZ%207000%20Technology%20Zero%20Voltage%20Transmission%20(ZVT).pdf "A significant technical achievement of GPZ 7000 ZVT technology was in creating the ultra‐stable transmitted magnetic field during the receive period, to ensure that the large reactive component of the soil signal, X, is not detected, in the same way that it is not detected in PI." Figure 2 shows a comparison between the ZVT VRM soil signal and the nearest equivalent PI soil VRM signal; both transmitted magnetic signals being bi‐polar, with the same fundamental frequency and same rapid change of magnetic field period. It should be noted that the PI receive period is half that of the ZVT period, because the PI system shown in figure 2 transmits for half the time and receives for the other half of the time, unlike ZVT that transmits and receives simultaneously just about all of the time. The important difference in the VRM signals is that the PI signal decays away substantially faster than the ZVT system. This indicates that the receive signal for PI is less sensitive to longer Time Constant (TC) components compared to shorter TC targets than ZVT, and this is one of the main reasons why ZVT technology is better at detecting large nuggets compared to PI; another main reason being from the double length receive period in ZVT compared to PI for the same fundamental frequency.
  6. Hi, Regarding the VLF detectors.Can someone answer for me what constitutes a VLF with good discrimination?.I feel to discriminate that speed is a factor as well.Otherwise no matter how good,if a target is next to iron it will read off a good hit. The Deus has fast reactivity,so is this now a good discriminator.Between ferrous and non ferrous?. How does this compare to say the Nokta Impact for speed discrimination. Thanks in advance Ash
  7. The more I learn (by reading and experience) the more I realize that unmasking is the holy grail future of induction balance (IB) detectors. Dankowski has been emphasizing the issue for years (as your link to a 2000 article shows Dankowski - Beneath The Mask). The sites I hunt are visciously peppered with iron, small and large. That goes for old homesites here in the Midwest and out West, at old abondoned mines, placer sites, and ghost towns. As bad as littering is today, at least we have trash barrels, recycling, refuse collection, and advertising pleas to keep the world a beautiful place. I get the impression that back in the 19th century the thought didn't even occur to them. People can still cherry pick (using strict discrimination) to avoid the trash. If all you're after is recent drops (clad, zinc, and maybe a few pieces of silver jewelry) then go for it. I want old stuff and, as you note, that means dealing with lots of trash. But even careful hunting today is hampered severely by masking. As Tom D.'s report shows, not only don't you hear the good target, sometimes you don't even here the bad ones! How do you know there might be good target being masked if your detector responds as if there is no metal at all within its search field?! It's my impression that masking is just as big of a problem for nugget hunters. Does it just get less attention because most nugget hunting is done with pulse induction (PI) and zero volt transmission (ZVT) technology, which (AFAIK) doesn't offer much discrimination anyway. If you're really going to dig-it-all, including iron, then eventually you're going to find just about every piece of detectable metal within range.
  8. http://md-hunter.com/new-xp-q-mond-machine-novelty-2018-look-at-that/ Is this for real, why not go with the smart phone?????????
  9. Hello, Does the coal or carbon block the EM signals? For example if the metal object buried and covered by shield of carbon or coal. Does the metal detector able to penetrate this type of materials.
  10. I think I could show more interest in any of Garrett detectors but in my opinion they try to put too much info in such a small area. They could take a lesson from White's and let it pop up on the screen on what you detected. This looks like what Minelab is doing the same as White's with a big and better display so all has no trouble to see. I don't see myself buying anything from Garrett until they do. White's has some for the same reason I wouldn't buy either. The young will buy the small screen but with a large one the younger and older will buy. So detector companies you want your sales to go up then come out with a larger display. Chuck
  11. I was wondering about this new machine to hit the market and do believe other manufactures are also releasing soon, the same or very similar type of technology.I dont belive it s new.Can we obtain a list of the main players who will be releasing something similar so i may do a comparison.I think Fisher has one but dont think the At Max coming soon is the same.I m asking this as im not 100% tech savy but dont believe Minelab is the first here or by any means the best.In saying that ,this machine looks very sweet indeed.Also last point.In regard to reactivity speed ,where does the AT Max come in.Thanks in advance. Ash
  12. So Steve or somebody explain to me, putting aside higher frequency is more sensitive to tiny objects like gold nuggets. I realize that. Does higher or lower frequencies go deeper? is there any difference for general coin or relic hunting? Would one or the other pick up or let me hear better a deeper fainter signal?
  13. I always have one question in mind which is the best frequency for silver and gold jwellary or treassure hord at the same time i know 7 to 15 khz is for silver relics tressure 15khz to upper is for gold suppose if i find a cannal full of silver and gold jwellary which frequency is best suited for it
  14. Looks funny but there is not far between this video and a decent beach detector at least. Just need the digger scoop arm on the back. Kind of like turning a Roomba loose on the beach!
  15. I often see posts on various forums where people use high GB phase numbers as examples of hot, mineralized ground. I thought that GB phase numbers are only indicative of the TYPE of ground(rock,soil,clay,salt). Rock, soil, and clay can actually be pretty benign or very mineralized. Isn't the determining factor for hot ground that affects metal detectors the amount of Fe3 in the soil? A phase reading of 89 may be mild soil if the amount of IRON in the soil is low. Conversely a phase reading of 65 may be very hot ground if the ground consists of clays with high iron content. Some VLF detectors now have Fe3 meters on them and the higher the reading is on that meter the more the ground will affect your detection depth and the accuracy of the VDI number(if supplied). It seems like many people are confused by this. I think it is important info that can affect your coil selection(size and type), the amount of discrimination you may choose to use, and the mode(all-metal or discriminate) that we run in. We need somebody that knows their stuff to give us a definitive answer!
  16. Steve, your a great source for unbiased information. I trust your opinion greatly. Don't fret over what just happened. Many many people view you as a great resource. As you know I have been metal detecting for 30 years. I still consider myself a newbie. However, it is with the same old machine. Back when I purchased my machine we were told it will detect everything, it's a do all machine. I new of prospecting machines, but never knew the difference or seen the demand until I came to this forum. So if you have time, please answer these question. I am going to throw these out as I don't really know how to ask the correct question. What if the difference in a gold machine vs a regular machine? What makes them stand out? I know there is a frequency difference, but what make them stand on when looking for gold? Are they just not tuned for gold?
  17. On his forum at http://www.dankowskidetectors.com/discussions/read.php?2,121626 This gives a very rare, in fact as far as I know, never before seen inside look at the prototyping process and field test reporting. Thomas Dankowski is a true "engineer nerd" (I say that as a compliment) and so goes to extreme lengths and detail beyond what would normally be seen. His extremely lengthy and copious notes also provide many insights about what to possibly expect from the new Nokta Impact. Keep in mind things changed from the early reports to the final product so things Tom talks about early on change at later dates. Quoting from his thread out of context could cause a lot of misperceptions to arise. The thread well illustrates something I have observed for some time. When it comes to max depth, standard single frequency induction balance detecting technology is tapped out. Look at the struggle to obtain not another inch but even just another 0.1 inch of depth. The main advantages have come as of late in recovery speed and the ability to separate closely spaced targets. Max depth however is at a standstill. Tom's testing just confirms what I have been seeing for years. It is near impossible to discern more than hair splitting differences for max depth between most top of the line VLF detectors these days. And now a Report on the Nokta Impact from Keith Southern And a Report From Ziggy Report from Lawrenzo - Low-Boy/LCPM Report from tnsharpshooter Report from goodmore Report from Sven1
  18. Steve, Every since you posted that you lose depth when you ground balance, It is in the back of my mind........ "Ground balancing is a filter and not all that different that the way the discrimination system works. The ground signal or salt signal (or both) are identified and then tuned out. The ground effect is still there, but the detector subtracts it from the overall signal. The key word there is "subtracts". Ground balance methods work by subtracting part of the signal, and all subtractive methods create depth losses of some sort the closer any detected item gets to the "hole" created by subtracting the ground or salt signal. Signals are not perfect but spread over a small range, and so eliminating any signal usually means taking out a small range of signals. " I have always tried to keep my detectors ground balanced while using them.... Now I wonder if I should? Can you put my mind at ease......
  19. I got my first metal detector in 1986. It was a White's Coin Master 6000 DI Pro. I bought it because I live near the beach and a friend of mine had a friend who was selling them. I didn't know much about detectors and I used it on the beach in the dry sand only for about 3 years before life happened and I put it away. I didn't get another detector until 2010 and it was a ML 5000. Now that I had it I had to start learning about the desert and more about metal detectors. One of the first things that I 'noticed' about a detector is that you don't have to be directly over a target to hear it. You get a sense for a target by coming close. You get a bigger sense for an aluminum can than you do a quarter for instance. I've searched and searched over the years for a way to describe this near to target sense which is much greater in the 5000 (PI) and the 7000 (ZVT) than with the Coin Master (VLF). Today I was reading an email from Kellyco who is the company that services most Minelabs in the United States. They also sell most other detectors and give advice to their customers. The email that I received led me to a reprint of an article: How Metal Detectors Work Reprinted with permission from Modern Metal Detectors. The full article is here: https://www.kellycodetectors.com/catalog/how-metal-detectors-work#more In that article it uses the term Fringe Area Detection and that gave definition to what I had been trying to describe for years. I had tried to say a coil is like a Nerf ball with many targets off the search area and you are drawn to a target like a moth to a flame. As it turns out this is just 'fringe area detection' which lets us push our detectors to much greater finds. I think you will see how many times we have discussed this part of metal detecting without using this term. The fringe area on my 7000 is larger than the illustration shown. Here is what the article says about fringe area detection: Fringe Area Detection Fringe area detection is a phenomenon of detection, the understanding of which will result in your being able to discover metal targets to the maximum depth capability of any instrument. The detection pattern for a coin may extend, say, one foot below the search coil. The detection pattern for a small jar of coins may extend, perhaps, two feet below the search coil as illustrated in the drawing on the facing page. Within the area of the detection pattern, an unmistakable detector signal is produced. This illustration shows the location and approximate proportional size of the fringe detection area in which faint target signals from around the outer edges of a normal detection pattern can be heard. What about outside the detection pattern? Does detection take place? Yes, but the signals are too weak to be discerned by the operator except in the fringe area around the outer edges of the detection pattern as shown in the drawing above. A good set of headphones is a must, if you desire to hear fringe area signals. The next more important thing, is training in the art of discerning the faint whispers of sound that occur in the fringe area. Skill in fringe area detection can be developed with practice, training, concentration and faith in your ability. Develop fringe area detection ability to a fine art and you are on your way to some great discoveries that many detector operators will miss. The ability to hear fringe area signals results in greatly improved metal detection efficiency and success. Mitchel
  20. If somebody has offered you at option: 1. to reduce the weight of your favourite detector by half 2. to increase its depth by 10% What would you choose?
  21. No, I'm not talking about politics and being a Moveon.org trainer. I'm talking about resistivity detecting. Electrical resistivity tomography From Wikipedia, the free encyclopedia Electrical resistivity tomography (ERT) or electrical resistivity imaging (ERI) is a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface, or by electrodes in one or more boreholes. If the electrodes are suspended in the boreholes, deeper sections can be investigated. It is closely related to the medical imaging technique electrical impedance tomography (EIT), and mathematically is the same inverse problem. In contrast to medical EIT however ERT is essentially a direct current method. A related geophysical method, induced polarization, measures the transient response. The technique evolved from techniques of electrical prospecting that predate digital computers, where layers or anomalies were sought rather than images. Early work on the mathematical problem in the 1930s assumed a layered medium (see for example Langer, Slichter). Andrey Nikolayevich Tikhonov who is best known for his work on regularization of inverse problems also worked on this problem. He explains in detail how to solve the ERT problem in a simple case of 2-layered medium. During the 1940s he collaborated with geophysicists and without the aid of computers they discovered large deposits of copper. As a result, they were awarded a State Prize of Soviet Union. Andrey Nikolayevich Tikhonov, the "father of ERT" When adequate computers became widely available the inverse problem of ERT could be solved numerically, and the work of Loke and Barker at Birmingham University was among the first such solution, and their approach is still widely used. With the advancement in the field of Electrical Resistivity Tomography (ERT) from 1D to 2D and now-a- days 3D, ERT has explored many fields. The applications of ERT include fault investigation, ground water table investigation, soil moisture content determination and many others. In industrial process imaging ERT can be used in a similar fashion to medical EIT, to image the distribution of conductivity in mixing vessels and pipes. In this context it is usually called Electrical Resistance Tomography, emphasising the quantity that is measured rather than imaged. https://en.wikipedia.org/wiki/Electrical_resistivity_tomography Here is one unit being offered by Kellyco. https://www.kellycodetectors.com/blog/find-gold-resistivity?utm_source=email&utm_medium=BlogBUTTON&utm_content=BlogGoldResistivity&utm_campaign=MSTRBlogGoldResistivity20170624&utm_term=Lead_SuperBowlGiveaway2016 Mitchel
  22. As a rule do the lower vlf frequencies punch deeper than the higher ones, say 4.8 verses 14khz? But what is the trade off? Are some frequencies better for silver coins? How does iron enter into this? Need to understand how this all fits together! Thanks for any and all answers.
  23. A lot of detectors let you notch out (silence) a target identification (TID) band but are there any that let you choose which tone (audio frequency) to assign to a band?
  24. Can someone please explain the differences in a PI machine and a VLF machine in layman's terms or point me in a direction on the site if it has already been posted up some where just trying to learn
  25. I know this topic has appeared off and on over the years, but I'd like to better understanding on the theory and principle of using one over the other, ie. depth, and target id and what compromises do I induce. The reason I ask is the new V4 for XP Deus has the ability to set a minus discrimination. It kills the ability to use the "horseshoe" screen for ferrous target ID, but VID numbers are tolerable. What theoretically happens if I set a negative discrimination, but use Notch to handle ordinary ferrous trash?
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