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  1. 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
  2. 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?
  3. 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
  4. 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!
  5. 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?
  6. 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
  7. 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......
  8. 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
  9. 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?
  10. 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
  11. 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.
  12. 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?
  13. 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
  14. 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?
  15. Can you guys help me to compile a list of all current VLF detectors on the market that will run in a true ALL METAL no/non motion setting as a user defined base mode, not a hold trigger or pinpoint button held type option but a base mode of operation. Much like what the original M Scope Fisher Gold Bug 19 khz unit operated as. I am seeking a VLF unit with least amount of or no discrimination that operates in all metal no motion, ability to turn up gain and sens as well as GB preferred and has ability to add large format aftermarket coil. I believe that the Tesoro Outlaw has all metal no motion mode.
  16. Is Minelab the only one that uses electronic noise cancel feature?? Do they have patents associate with this feature? Would like to see other manufacturers use some thing similar on their detectors. Or a manufacturer should provide actual visual indication of emi levels depending on frequency used to include offsetting. Not have the user have to use their ears to decide or even try comparing on buried targets. Should not be trial and error. And maybe even a system were the operator is warned,,say if emi changes and the current selected frequency is possibly not operating at optimum. I do realize with a coil being swept over the ground, this could be difficult to do.
  17. For over a decade I've ask for one small feature to a good detector. Say for instance on the Fisher F75 detector or another machine of comparable abilities. Add a two tone function in the motion all metal mode. Nothing fancy, just one tone for ferrous and another for non-ferrous. Being a computer programmer for several years I can't imagine this would be very difficult. Now on the F75, while in motion all metal mode the machine gives better depth and also gives an ID for detected metal objects. So since nothing is really needed except assigning a tone to the ID number scheme why is it so hard to acquire a unit with that feature. I know the V3i has a feature similar, but it lacks the depth capability of the F75 in my ground. Now I've ask again. I'll check back in another decade.
  18. On subject of coils and systems... I was out working some areas for relics with a couple others and one guy was killing it with an very vintage 70s Garrett Master Hunter BFO unit with a large home made looking square coil of pvc looking material. After looking into I found that BFO is Beat Frequency Oscillator and was popular before T/R VLF format machines. BFO was not good for small coin shooting and nugget hunting and lacked ability for quality discrimination from what I read but excelled in depth ability, especially on large ferrous cache targets as well as finding mineral deposits like drifts of black sands or veins of ore. So are there currently any units that still use a BFO mode or format? I can find vintage BFO type units available very reasonably priced, is there any information out there on how to bring them up to current on a battery system and build large coils suitable for this type of cache detecting?
  19. Detector coils are not antenna. They are part of a highly tuned inductive coupling system.
  20. Good afternoon everyone, I am looking for a long range detector and I would like to know if anyone can design/produce a stand-alone (not hand held) long range detector suitable for detecting gold from a 30-50 metres height. This is a serious enquiry which foresees the purchase of large quantities of such locators/detectors as well as the development of different detectors for other metals/minerals. For a better idea of what I am looking for, please see my drawing below. Thanks, Law-Italy ( lawrencebon@hotmail.it )
  21. Everyone needs to watch this video. We talk all the time how lower frequencies ignore ground better and penetrate deeper on larger targets, but how high frequencies are better at getting small targets to respond. This video does a superb job of illustrating how high frequencies do a better job at "lighting up" a small gold target. The key is we are using one detector and coil with all the settings just the same - the only thing that changes is the frequency. This eliminates other extraneous factors that usually play into comparisons of this sort. What this video does not show is how higher frequencies not only "light up" the target but also mineralized ground, creating difficulty with penetrating deeply in that ground. One of the great lessons in metal detecting is that there is no free lunch, and very often improving one thing comes at a cost somewhere else. You can skip right to "the good part" at 2:45
  22. Note: thread was split from this previous thread Tone By TID Selection Option? Thanks for posting that reminder on the Fisher F44 Mike. I had forgot about it, and added the chart page to your post. To my mind for coin and jewelry detecting I simply have no interest in owning machines that do not allow me to customize tone ranges and tones. My current stable of coin/jewelry machines are the White's DFX, Minelab CTX, Nokta Impact, and XP DEUS, and all four offer this capability (the ability to customize tone ranges and tones) in one form or another. It really is a killer feature on the F44 at such a low price, only $349 these days. If all I could have is one detector and had to buy a new one under $400 I have no doubt the F44 is what I would end up with. Funny that it gets so little interest on the forums but I guess that reflects the fact most of us tend to be using higher end product. This is a case where Fisher may have sold more by pricing it higher! People may snicker at that but there are sound sales reasons for why that may be true. Look at what you get in a Gold Bug Pro and you would think it should be $349 and the F44 should be $649. Fisher F44 metal detector
  23. For background on electrical interference in VLF detectors here is a great essay on electrical interference by Dave Johnson of First Texas Products. You can also find a more detailed discussion that includes PI detectors in section 2.1 of this Minelab document by Bruce Candy. OK, so I am bench testing my new Teknetics G2 at home recently. The 19 kHz models are renowned for being immune to EMI (ElectroMagnetic Interference). No electrical interference ever (well, almost never) even at highest gain levels. As a rule, the lower the frequency, the more issues you have with EMI. It is especially bad under 10 kHz. DEUS owners may see significant EMI at 4 kHz, only a little at 8 kHz, and none at 12 and 18 kHz. Another reason why manufacturers favor mid frequency over low frequency detectors these days. I have been bench testing detectors in my house for years so think I know the EMI levels. No issues with previous 19 kHz units like the Gold Bug Pro and F19. Yet this new G2 chatters like crazy! I fire off an email to First Texas asking if some change I was unaware of. Nope. And could not be a bad coil because both coils I have did it. Then on another go I noticed the EMI was bad on one end of house but not the other. I walk around and the detector leads me to a new LED bulb I installed recently. This thing is pumping out 19 kHz EMI like crazy! Not long ago I installed a number of these cheap LED bulbs in my house. https://www.amazon.com/Feit-Electric-Replacement-CEOM60-927/dp/B01BJ0Y1MC Looks like my mission to upgade my house to all LED just ran into a snag! More on LED bulb interference - https://www.google.com/search?num=30&q=led+bulb+electrical+interference&oq=led+bulb+electrical+interference Just shows how more and more we are surrounded by new forms of electrical interference to make life harder for detector engineers.
  24. I am going to bring this up for you to maybe shed light on. Since you have been it seems testing and using detectors for a while. First up,,,has any manufacturer who you are testing a detector for,,,have they ask you if you are currently testing any other manufacturer's model detectors (prerelease)?? Next since you likely signed non disclosure agreements,,,and they are pretty straightforward,,,like you can't discuss or talk until you are given ok to do. I consider you a very ethical person btw,,,this next question is not to insinuate anything,,,I just want to hear your thoughts here. What about if you are testing a unit,,,and let's say the testing phase is more or less concluded,,,but this specific detector model isn't quite released yet,,,and you happen to be testing another unit from a different manufacturer. Is it proper to use this detector you have already tested (not released yet) and do head to heads with another test unit,,,and this other unit let's just say is still further from official release than this other unit. So in keeping all this head to head under wraps,,,but when the first unit you tested is released,,,obviously the non disclosure agreement is null and void on this unit,,,,so with maybe some previous head to head testing done before this first detector release,,,so then a tester could actually maybe provide comparison data (done before first detector release) to the second detector's manufacturer when the first one releases. I hope this makes sense. Remember I'm not insinuating anything,,,you are far more expert in this dept than I. And obviously comparing a detector under formal testing to an already publically released detector is a different animal,,I see no problems doing this. Steve do you think a person should be testing 2 or more detectors (pre release) simultaneously from different manufacturers??
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