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  1. On the Anfibio Multi (and I think Kruzer & others) there is a definite step in sensitivity between 39&40 Gain and again between 69&70 Gain. Is this a change in the Internal Threshold? In a way this would be the inverse of the way the F75 adjusts sensitivity according to Mike Hillis. Regardless, it is a very good set up in difficult sites. Most NM users know about the difference in response speed between 89 & 90 Gain on 3DI. This is different. I had read about these steps in a forum post that quoted Alper of NM. I can't seem to find that post now that I want to re read it.
  2. Not sure where this belongs on the forum, (or if it even belongs here), but this seemed to be the best category to discuss this. Ever since information on the GPX 6000 started to trickle out, I had this nagging feeling something in detecting has changed for those of us who like the thrill of getting to know a new detector. I never would have envisioned the GPX line morphing into a simplified detector. After having the GPX 5000 for a bunch of years now, and using it for relic and beach hunting, I could not imagine relying on a machine that adjust everything for you. I get it that money talks, and when you are a publicly traded company, you go for profit first, and then deny it 😄 And now that there market has switched to an area that probably has very little experience with detectors, the GPX 5000 must have been daunting for them. So they cater to that market. But I was hoping that a new GPX would fix some of the issues that the 5000 had. I was naive. Minelab has never kept the good parts of their previous machines and just added the the things that needed improvements. On the E trac, the best part of it was the depth it had in finding deep silver, in long tones, multi. Also the bouncy numbers helped ID deep Indians. When the CTX came out, it lost some of that fluety tone and they tried to straighten out the numbers to a number 12 line. So a two dimensional screen that worked well was transformed into a 2 dimensional screen that bunched most targets on one line. The The EQ comes out and squashes out the numbers even further. So why I thought the 6000 would not do the same is beyond me. I guess I'm disappointing that the "trend" is to make machines where the manufacturer decides on how your machine is going to be set. I hope someone in my area gets a 6000 and is willing to bring it to the beach to compare settings on deep silver. If it wins, then I will eat my words. I know I will get some slack with people saying it's a gold machine, not a relic or beach machine, but to them I would say.... you should be worried when a company controls your ability to fine tune your machine. Thoughts?
  3. https://patents.google.com/patent/WO2021016649A1/en?assignee=minelab&scholar&oq=minelab&sort=new This is the most out of this world Minelab detector patent I've ever read. There is so much here, some very sci-fi like, I don't even know where to start. My takeaway is they seem to be positioning themselves for a drone based detector eventually (main details in this patent could be easily transferred to a drone based platform - IMU, GPS, magnetometer, heads up display, FPV, remote control, robotic/vehicle mount, etc) . That is 100% a guess. But in the meantime, there is some interesting, novel items in the pipeline that we might actually see on a machine in closer future? No clue if this is a coin machine or gold machine or if it's something they are actually working on right now or just trying to get control patents on such things for the future which may or may not arrive. One thing is for certain, Minelab is BUSY in the engineering department. A few of the highlights: Heads up display over glasses/head mounted display (aka augmented reality). Settings, target visualization, shading of detected/not detected areas (I asked for this specifically 5 or 6 years ago here, awesome to see it in a patent now). Plus a camera showing the coil (why would you need that if not operating remotely as from a drone?) The detector has a camera, IMU (accelerometer) and magnetometer to determine position with accuracy. The IMU tracks the position of the coil in real time in relation to both the ground and the target, and combined with the camera video feed will provide a "visual" of the target in the ground through the glasses/head display, as in form of a heat map which increases accuracy with each pass of a coil over the target. A GPS tracks the machine position to properly map the IMU/coil visual target data on the ground and let's a user see the mapping as they detect. This data is recorded for future historical use and can be shared. Centimeter accuracy with the visual target heat mapping. Potential operators/users include entities other than humans such as "robots" and "an AI (artificial intelligence) using a metal detector" and this line: "The metal detector may be handheld, mounted on a robotic arm of a vehicle or a robot." Wireless connectivity to computers and phones, transfer of files containing settings configurations from instructors or expert users Remote control of the metal detector through apps on laptops or phones Ability to upload maps, including detecting data, historic human activity, buildings, or other items that seem to indicate custom mapping capability Internet connectivity, potential control through the internet (again, why if not for a drone type device?) "Teamspeak" to other detecting members in the area wirelessly Visual/spatial discrimination Accurate depth measurement Synthesized audio mode, eliminating noise completely and allowing the detector to "recreate" a synthetic audio stream based on data from prior swings Delayed audio processing (enhanced audio) mode or real time audio mode, ability to seperate multiple close targets, reason for this I venture a guess why below ---> This patent actually seems to be describing a completely new method of RX in a detector. Which is actually similar in some ways to the wacky idea I had years ago of reducing EMI/ground noise by emulating a radio telescope array. But in this case they appear to be describing a fairly ingenuous method of doing something similar with only one coil by monitoring RX of the same target at different points in the swing (with the IMU tracking these points) and combining all those RX signals. In this way (and this is my guess, the patent doesn't explain this), you can form a sort of comparator, gradiometer, or interferometer to seperate the wheat from the chaff, so to speak. If that's what they are doing, then I find it to be brilliant. If not, then I just gave them one hell of an idea to patent for the future. That probably sounds like jibberish to non-engineers. But I want people to understand the brilliance in simple terms. Consider this: EMI is random. At any given point in your swing you'll get noise here, but not there. So if you compare two points in the same swing, you will hear noise one point but not the other point because the "zap" already ended. But you might hear a good target at both points in the swing since it's not random like EMI, it's always there in the ground. So, you can effectively eliminate EMI by comparing what signal is not there at two very close points in the swing, and keep the target since it's always there. Similarly, with ground, the ground changes as the alluvium changes since soil is inhomogeneous. But a target is still the target. So, a similar method can be applied to the ground. In theory, you could use ideas like this to essentially get rid of the Difficult type timings and keep your gains boosted high, and deal with EMI/ground in this way instead which does not require reducing sensitivity. A totally new, novel approach to RX in a metal detector. The audio processing is very slightly delayed because they are using that time to compare measurements at a few different coil positions before letting the audio processor signal that there is a target present. That's my guess. If that isn't what they are doing, then someone else should patent that and thank me for it later when Minelab buys it. Either way, they have something totally new in the RX department here. And the future of detecting looks bright and interesting to me still.
  4. Hello, now here’s an opener that might just get me banned on my first post! Bear with me, my intentions are pure :) Does anyone know if it would be possible to jam an MD signal? The reason I ask is to combat the evident problem we have in the UK with “nighthawks”, illegal detectorists. Over here, any landowner can grant permission for detecting on their land (with caveats, known historic sites are protected by law). What often happens is that such a permission is granted and a detectorist innocently sets about his / her business. Someone less scrupulous spots this person and assumes there may be something important there, so shows up at night with a couple of friends and the landowner awakens to a field / lawn full of holes, then bans metal detecting. Historic sites are also looted. Just an off the wall question, how tricky would it be to build a device to block this on a piece of land? Anyone any ideas?
  5. Found this patent that Whites filed and got a patent on in 2014 on a hybrid IB/PI machine. https://patents.google.com/patent/US20110316541A1/en Curious if anyone heard anything about this. Maybe Garrett will take it on?
  6. Which metal detectors have the most reliable target ID numbers? Target ID is a function of depth - the deeper the target, the more difficult it is to get a clean target ID as the ground signal interferes. Other items directly adjacent to the desired target can also cause inaccurate numbers. The more conductive the item, the higher the resulting ID number, but also the larger the item the higher the number. Silver is more conductive than gold, so a gold item will give a lower number than the same size silver item. But a very large gold item can give a higher number than a small silver item, so numbers do not identify types of metal. Gold and aluminum read the same and vary in size so to dig one you dig the other. Only mass produced items like coins produce numbers that are more or less the same over the years but a zinc penny will read lower than a copper penny due to the change in composition. In general iron or ferrous targets produce negative numbers or low numbers. Aluminum, gold, and US nickels produce mid-range numbers. And most other US coins produce high numbers. Other countries coins, like Canadian coins with ferrous content, can read all over the place. The scale applied varies according to manufacturer so the number produced by each detector will vary according to the scale used. The 0-100 range for non-ferrous targets is most common but there are others. Minelab employs a dual number system on a 2D scale with thousands of possible numbers, but they are now normalizing the results produced to conform more closely to the linear scale used by other manufacturers. White's Visual Discrimination Identification (VDI) Scale Increasing ground mineralization has a huge effect on the ability to get a good target ID. Ground mineralization is nearly always from iron mineralization, and this tends to make weak targets, whether very small targets or very deep targets, misidentify. The target numbers get dragged lower, and many non-ferrous targets will eventually be identified as iron if buried deep enough. Small non-ferrous readings and iron readings actually overlap. That is why any discrimination at all is particularly risky for gold nugget hunters. If you want target ID numbers to settle down, lower sensitivity and practice consistent coil control. The target number will often vary depending on how well the target is centered and how fast the coil moves. Perfect ground balance is critical to accurate target id. Outside issues factor in. Electrical interference is a common cause of jumpy target id numbers. In general small coils will often deliver sharper, more consistent target id returns. Higher sensitivity settings lead to jumpier numbers as the detectors become less stable at higher levels. The interference from the ground signal increases and interference from outside electrical sources also increases, leading to less stable numbers. Higher frequency detectors are inherently more sensitive and are jumpier. So lean lower frequency for more solid results. Multi frequency detectors act like low frequency detectors and tend to have more solid target numbers due to the ability to analyze a target with different frequencies. Another issue is the number of target categories, or ID segments, or VDIs, or notches, or bins (all names for the same thing) that a detector offers. For instance here are the number of possible target id categories or segments each detector below offers: Fisher CZ-3D = 7 Garrett Ace 250 = 12 Minelab X-Terra 305 = 12 Minelab X-Terra 505 = 19 Minelab X-Terra 705 = 28 Minelab Equinox = 50 Fisher F75 (and many other models) = 99 White's MXT (and many other models) = 190 Minelab CTX 3030 = 1750 Fewer target categories means more possible items get lumped together under a single reading, but that the reading is more stable. Many detectors will tell you the difference between a dime and a quarter. The Fisher CZ assumes you want to dig both so puts them under one segment along with most other coins. People who use detectors with many target numbers usually just watch the numbers jump around and mentally average the results. Some high end detectors can actually do this averaging for you! But I think there is something to be said for owning a detector that simplifies things and offers less possible numbers to start with. The old Fisher CZ method still appeals to me, especially for coin detecting. So do detectors like the Garrett Ace 250 or Minelab X-Terra 505 for the same reason. The problem is that as people strive to dig deeper targets or smaller targets the numbers will always get less reliable. But if you want to have a quiet performing metal detecting with solid, reliable target numbers look more for coin type detectors running at lower frequencies under 10 kHz or at multiple frequencies and possibly consider getting a detector with fewer possible target segments. And with any detector no matter what just back that sensitivity setting off and you will get more reliable target numbers. ads by Amazon... Detectors often use tones to identify targets and often use far fewer tones than indicated by the possible visual target id numbers. The X-Terra 705 for instance can use 28 tones, one for each segment. However, most people find this too busy, and so simple tone schemes of two, three, or four tones may be selected. I think it is instructive that many people often end up ignoring screen readings and hunting by ear, using just a few tones. This ends up just being an ultra basic target id system much like the simpler units offer. Reality is that most people do not need or care about huge numbers of target numbers. For many just three ranges suffice, low tone for iron, mid tone for most gold items, and high tone for most US coins. The meter could do the same thing, but for marketing purposes more is better and so we get sold on detectors with hundreds of possible target ID numbers. Perhaps this is a digital representation of an old analog meter with its nearly infinite range of response but the reality is we do not need that level of differentiation to make a simple dig or no dig decision. Finally, a picture often says it all. Below we have a shot of the White's M6 meter. I like it because the decal below illustrates a lot. You see the possible numerical range of -95 to 95 laid out in the middle. Over it is the simplified iron/gold/silver range. Note the slants where they overlap to indicate the readings really do overlap. Then you get the probable target icons. -95 is noted as "hot rock" because many do read there. The M6 can generate 7 tones depending on the target category. I have added red lines to the image to show where these tones sit in relation to the scale. It breaks down as follows: -95 = 57 Hz (Very Low) Hot Rock -94 to -6 = 128 Hz (Low) Iron Junk -5 to 7 = 145 Hz (Med Low) Gold Earrings, Chains - Foil 8 to 26 = 182 Hz (Medium) Women's Gold Rings/Nickel - Small Pull Tabs 27 to 49 = 259 Hz (Med Hi) Men's Gold Rings - Large Pull Tabs 50 to 70 = 411 Hz (High) Zinc Penny/Indian Head Penny - Screw Caps 71 to 95 = 900 Hz (Very High) Copper Penny/Dime/Quarter/Dollar Note that the screen reading of +14 is noted as being a nickel or ring but it can also be the "beaver tail" part of an aluminum pull tab or the aluminum ring that holds an eraser on a pencil, among other things. The best book ever written on the subject of discrimination is "Taking A Closer Look At Metal Detector Discrimination" by Robert C. Brockett. It is out of print but if you find a copy grab it, assuming the topic interests you. Always remember - when in doubt, dig it out! Your eyes are the best target ID method available.
  7. I know we have had some great advancements in VLF metal detector's over the recent past, but I am hoping that we can keep some of the older design features that seemed to work well. My favorite new technological features being offered in VLF's are Multi-IQ and single frequencies options, fully programmable settings, waterproof, noise cancel, USB chargers, li-ion batteries, Bluetooth headphones, prospecting & coin/relic options, and lightweight. Really a great job by the inventors of these detectors. IMHO I hope we do not lose some of the past designs that worked well, such as the ergonomics of the balanced s rod that would separate in three places for backpacking, the hip mountable brain box, the detectors that would not fall over when put on a little bit of an uneven surface, the 6.5 inch elliptical concentric or double DD coils for great access in rocky areas, the 1/4 inch headphone jack, the spare interchangeable battery pack that takes regular batteries to serve as a back-up for the li-ion battery pack, and higher frequencies options. I would like to see what else had worked well with other detector user, seems like we are always buying aftermarket parts to retain some of these older features where possible.
  8. Good morning all! I saw a post yesterday where someone mentioned the possibility of linking the equinox to an audio analyzer to get a visual readout on target tones and I found the idea fascinating. I've never seen this done and was curious what the old hands here thought about the idea. I'm sure the engineers at minelab (or any other shop) configured the sound of their machines with the human brain in mind, so our wetware may already be the best analyzer there is. But I can't help but wondering if a visualization of the audio would provide interesting heretofore undetected differences in targets that appear to be mostly indistinguishable to a rookie ear, namely uniform can slaw and pulltabs. Anyone here have any idea?
  9. Greetings to all! My name is Alexander, I am from Ukraine (Eastern Europe). I represent myself and my friends, we developed a portable type GPR many years ago and gave it the name EasyRad. We have developed a georadar and software for it. We would like to get in touch (get contact) with those people or organizations who need to search for gold in the United States and Alaska. To my regret, on forums of gold prospectors and forums of archaeologists there are no sections "georadars", there are only metal detectors. I would like to convey to the searchers the information that GPR is not expensive and it allows you to explore underground spaces quickly and with great interest 🙂 We produce this GPR equipment, so we can answer all your questions. Our radar has a very affordable price for individual use, unlike other radars. See the web link below for examples. EasyRad GPR is a portable multi-purpose scanning ground penetrating radar of sub-surface probing for the problems of engineering geology, hydrogeology, archeology, ecology, field engineering as well as for search and rescue operations. https://www.easyrad.com.ua/index.php?r=index_en
  10. XRF's hold sort a mysterious place on the shelf of semi-unobtainable prospecting equipment. 99% of prospectors don't need one. Maybe this post will help clear up some of mystery around these devices, and show where they can actually be worth the outlay of capital. And why for almost all recreational/hobby prospectors, they are not worth the money. What does an XRF do? In very simple terms you point it at an object and it will tell you what elements are in that object. More on this, and why it isn't this simple, momentarily... After sometime over 5 years of searching, I was finally able to find a used XRF I could afford to finance recently. These are not tools for recreation. They are expensive and require understanding how they work, what tasks you need to accomplish, and understanding the limits of XRF. The trick with these units is to find one with the proper calibrations already installed as they can be many thousands of dollars to send to the manufacturer to get configured correctly for mining/prospecting uses and to add/subtract elements or to calibrate for certain matrixes (silicates/iron/etc). X ray tubes and X ray detectors are about $6k each to replace, and recalibrations are about $1500 a pop, so even maintenance is crazy expensive. It's a tool you need be certain you need or can put to good use before buying one. And buying used, it's probably best to find one with as few hours use as possible to delay the inevitable tube replacement, as well as with a recent calibration certificate. My unit is an XMET 7500 made by Oxford (now Hitachi). The more common units people generally see are the Olympus and Niton guns. This unit has basically every mining calibration Oxford offered on it in addition to soil and other specialized mining related modes, which is very valuable and very useful for prospecting. It also detects down to magnesium without any fancy helium purge techniques. The guns sold on ebay with only alloy calibrations are pretty useless for prospecting without spending a lot of $$$ on additional calibrations. Some other things to consider are the machines themselves vary greatly between model numbers and some models may be unsuitable for specific uses in prospecting. A few things to educate yourself on are: Beam energy and detector type (determines if certain elements can be detected at all, and how accurately) Electrode composition (Gold electrodes have lower sensitivity to gold in ores, for instance) Calibration to light elements, or ability to detect certain elements I don't think an XRF is particularly useful for people who are only looking for gold. Due to the electrode limitations, the PPM minimum to detect gold in ores can often be above what would be an economic (and thus desirable) concentration in gold ores. But, looking for tracer elements (stuff like Pb, Cu, As, Zn, etc) can be quite useful. It can also help outline buried ore bodies which can then be explored mechanically via drilling or other methods. For prospectors branching out beyond just gold however, an XRF can be even more useful. And that's when one needs to understand the elemental limitations and what your application specific uses are. Any affordable XRF today will not detect lighter elements than magnesium. Some will detect to magnesium, but then do not contain calibrations to allow it (extra $$) and some require helium purging to measure light elements. Elements like hydrogen, carbon, oxygen, and sodium are very common "rock building" elements. But XRF readings will lack these measurements. So, when a looking at a rock your readings will often give fractional (less than 100%) results. This is why - the missing mass is tied up in atoms lighter than magnesium. Fortuantely, a lot of common rock types have unique fingerprints still in elements such as Mg, Al, Si, P, S, Cl, K, Ca, and Fe. But some don't. This is why it's important to understand what you are looking for first in the field, and then find a tool that is going to match your needs. Further, a lot of minerals in certain locations but not other locations will also have further fingerprints in other elements such as Cr, Co, Mo, Nb, certain compositions of rare earths, etc. To make it more complex (this part took me a while to wrap my head around), each calibration within the machine may or may not be configured for some of these elements - even if they are within the range of detection of the machine! Like, an alloy calibration will have little use for silicon or calcium. Conversely, a mining calibration without magnesium or calcium may be next to useless depending what you are looking for. Of course, it costs extra money to add elements and even if you have for instance a precious metals calibration that includes platinum, the mining mode may not itself include platinum and that's more $. That is why the matrix matters, each mode can be calibrated to a specific matrix. Like mining modes are generally going to assume that the sample is mostly silicon, whereas precious metals mode might assume the only things that exist in the universe are metals. So if you analyze solid metal with mining mode it may misidentify elements thinking they have to be metals when they aren't, same as if you analyzed a piece of gold ore in precious metals mode where it will try to assign certain non-metallic spectra in the ore to something like gold or platinum, giving you false positives. This is why calibrations available and elements assigned to that calibration is so very important when it comes to XRF and accurate results. Why else is XRF bad for gold-specific uses? (I emphasized this because this is primarily a gold prospecting site, even though I prospect for many other things myself). First one needs to understand how XRF works - simply put it kicks a few electrons out of a few different orbitals around an atom at discrete energy intervals (these are spectral "lines"). When another electron falls into the empty orbital to replace the vacancy, another X Ray is emitted at this discreet energy. Unfortunately, some elements have some very close to identical spectral lines. Look here at some lighter elements and see the overlaps on this visible spectra chart that we use to ID elements in stars? Some might be familiar with these from astronomy or high school. Well, the same happens in the X Ray realm. This is coincidentally why ionized gases look a certain color to us and how "neon" signs can be different colors (different elements inside the tubes). The same thing happens in the X ray spectrum, just not visible to our eyes. Except when the X ray spectra is reaaaaaaally crowded around the gold lines. Making it hard for specific ID's when other elements with similar lines are also present in ore, and unfortunately some of the elements are also commonly found with and around gold mineralization. Combine this with the anodes on many affordable XRF's being gold which itself interferes with really precise Au measurements, and you can see why an XRF isn't the best tool for specifically gold prospecting. Here is an actual XRF spectrum. You can see how very common accessory gold ore elements populate and crowd the gold spectral lines at various orbitals. And also how you might be missing critical lines if your X ray tube only goes to say 15kEV instead of 40kEV (EV stands for electron-volts), you might miss some Ag, Ru, Cd, or Zr fingerprints in this specific case. Now notice how iron stands all alone? That's why some elements (iron) are easier for an XRF to ID than others like gold. So for some such tracer elements in soils and ore, and identifying certain minerals which really can only be accurately identified via spectroscopy or thin sections as for some gems, an XRF can save months of time and thousands of dollars for in field qualitative assays to do first stage determinations, ie, wether a resource is simply present or not, ignoring actual concentrations. This is why it's so important for anyone considering one of these units to know exactly what they are looking for first, to know the limitations of XRF, and to know if a unit will meet their application specific needs. Almost every company I spoke with had a story about a prospector, or even a few cases some junior mining companies, who purchased an expensive unit only to find it wouldn't work at all for what they needed to do. So hopefully this clears up a little mystery about XRF's and maybe saves someone from making an expensive $15k mistake. I am by no means an XRF expert and everything I know is just self taught. So if I've included an inaccuracy then please correct me. This is not intended to be definitive, but just to share what I've learned over the years in a few pages of simpler to understand jargon for those prospectors interested in these devices. More later with some actual measurements...
  11. Metal detectors can be used for all kinds of utilitarian purposes in addition to their hobby and sporting uses. From finding property line markers to finding house sewers, there are all kinds of uses that can save both time and money for all kinds of home improvement and maintenance projects. Metal Detectors and Property Lines Markers What are property line markers? At some point in time, virtually every property has four long rebar stakes driven into the property corners by either a property owner or a real estate developer. Property boundary markers are important to be able to locate for construction projects and legal reasons, so that way you don’t encroach on your neighbor’s property. Finding a boundary line marker might seem like quite a difficult task, even with a metal detector. Just think about all of the nails, pop tabs, can slaw, and numerous other metal objects that are commonly found in yards. Ferrous vs. non-ferrous metals Metal detectors find Ferrous metals which include steel, carbon steel, stainless steel, cast iron, and non-ferrous metals which include aluminum, brass, copper, nickel, tin, lead, zinc, and other precious metals (gold, silver, etc). Property markers are usually made of solid rebar which is mainly made up of carbon steel. Carbon steel is a ferrous metal and most cheap metal detectors can pick this up. The rebar is buried only a few inches underground so as to not get hit by a lawnmower (1″ to 3″ depth). How do you find property line markers? One remedy to this is to find the plot plan of your yard or your property. This plat survey shows you exactly where the land developer or inspector drove the land surveying corner markers into the ground. It also shows you where the easements for various utilities and various city property are located in relation to your own property survey markers. Once you have a rough idea of where the property line marker will be located, it is simply a matter of metal detecting around the corner and finding the piece of steel. If the rebar happens to look damaged or like it may have been altered somehow, it may be important to double-check where the exact property lines are with a professional land surveyor. Metal Detectors and Surveyors Professional Land Surveyors Professional land surveyors perform all kinds of varied tasks, and many of these involve property boundaries and being able to locate various components of properties for landowners, whether it is gas lines, electric lines, or any other utility. There are also metal detectors that are built specifically with the land surveyor in mind and these are referred to as magnetic locators. These are designed to easily find ferrous metals. However, one of the most important features is the ability to discriminate against all kinds of metals except for the exact one you are looking for, in most cases steel. These metal detectors also have to be able to detect deep, especially when you want to search for property boundary markers and gas or electrical lines. Surveyors always have access to the plot plans for each property and will be able to use the marked utility lines and property boundaries to get close to where they need to be. Gas lines and electrical lines are easy to determine, as they are long and you will be able to find it several feet forward and several feet backward. Metal detectors are one of the greatest pieces of equipment that surveyors can use, as they save both time and effort for almost every surveying activity. Metal Detectors and Buried Sprinklers Sprinklers are a great addition to any yard, but sometimes they can cause serious headaches. When they get covered with dirt or just won’t come up anymore, it is important to find the issue and quickly address it before it leaves an impact on your lawn and garden. Luckily, sprinklers are very easy to find with metal detectors, as most sprinklers have many metal parts and are only a few inches below the ground. When you begin using the metal detector, make sure to have the sensitivity as high as you can until it starts intermittently beeping, then turn it down a notch, as there might not be a ton of metal in the sprinkler heads. It is a good idea to use iron discrimination because there is more than likely brass or some other alloy in the sprinkler. If you can get within close proximity of where you think the sprinkler head is, this can save you from digging a bunch of nails and pull tabs. If a previous owner installed them, you may possibly be able to contact them. Once you have found it, gently dig around it with a trowel or spade, being sure to not hit the waterline. Once this is done, you can perform maintenance or call a maintenance professional to get your sprinkler back in order. Using a metal detector is the best and fastest way to locate sprinkler heads in any yard. Metal Detectors and House Sewers Your home’s sewage system is one of the most important components you need to be aware of. When something goes wrong with anything involving your sewers, it is vitally important to figure out what is wrong and figure it out as soon as you can, as this can prevent expensive repairs. One of the best ways to find the various components of your home’s sewage system is to use a metal detector. If you live in town or a developed area, you will more than likely have a sewer main which runs underneath the road in front of your house. There is a lateral pipe that connects your home to this sewage main. If you live in the country or in some other scenarios, you will have a septic system that is connected to your house by the lateral pipe. There is also a cleanout that allows for access to your lateral pipe, and many times a piece of rebar is put near it in case it gets buried, allowing your metal detector to pick it up. Metal detectors can help you locate these various components if there is ever an issue and you will be able to see what is going on. If it is something simple that you can fix, that is great, but if it isn’t you might have to call in professionals. Either way, you will be able to save time and money by having located the components for the company. Best Metal Detectors and Magnetic Locators If you need a metal detector for any of these jobs, you have two options: you can decide whether you want to buy a machine for the long-term or rent a metal detector as a short-term purchase. There are pros and cons to both decisions, and what it ultimately boils down to depends on your situation. It’s common to rent a machine when your primary goal is to find your property line markers. Metal detectors can be pricey and it can get overwhelming when you don’t know a lot about them, so in this scenario renting a metal detector can be a great way to find your property line marker and test out a machine. Who knows, you may end up liking it and making a long-term purchase! Magnetic Locators The best machine you could use to find property line markers is a magnetic locator. As mentioned above, these machines are designed to easily find ferrous metals including rebar. Here are a few machines that we recommend using: The Fisher FX3 Ferro Magnetic Locator Probe The Fisher FML-3 Magnetic Locator The Fisher FP ID 2100 Magnetic Locator Metal Detectors and Accessories If you are just trying to locate metal that is close to the surface, you can get away with buying or renting less expensive, lower-quality machines. If you need to find pipes deep in the ground, a higher quality machine will have to be considered. For a budget metal detector, it is definitely worth considering the Bounty Hunter Tracker IV, as this metal detector provides everything you need for basic jobs, at a great price point. If you want a metal detector that can be used for basic needs, as well as finding smaller metal targets deeper in the ground, the Garrett AT Pro Metal Detector is durable and will get down deep in the ground to find exactly what you are looking for. If you absolutely need to find deep down targets, a professional metal detector such as the Nokta Makro Jeohunter 3D Basic will get the job done quickly and effectively. These are just a few of the metal detectors we recommend to get started on, but for more options check out our guide on the best metal detectors. Conclusion Operating a metal detector can be overwhelming if you’ve never used one, especially if your main goal is to find a property line marker. However, hiring a professional surveyor can get expensive. Whether you decide to rent or buy a metal detector, we recommend checking out any of our resources on the blog to help guide you through this process. How To Find Property Line Markers With a Metal Detector originally appeared on kellycodetectors.com
  12. I was out yesterday and remembered that the Gold Modes (I use Gold 1, if that matters) can be used to investigate iffy targets. Then I had a thought when I noticed a lot of ferrous hits per swing (likely nails) while searching in Park 1 (no notching/discrimination), gain of 24, Recovery Speed = 4, Iron Bias F2=0 -- I switched over to Gold 1 and the target rate per swing increased dramatically, something like a factor of two! (Note: there aren't hot rocks in this location and I checked that ground balance was correct. I'm pretty sure these are bits of iron such as nails or pieces of wire.) I also checked in Park 1, 4 kHz since there have been reports here that this sometimes eliminates iron grunts. That wasn't the case. This got me thinking about what the Gold modes are, or at least how they are different from the other modes. In limited testing (@40 kHz) I've found that they can detect coins deeper (or maybe 'farther from the coil' is a better description) than the other modes. Once again having to deal with the confusing (non-standard) nomenclature, it seems that the Equinox Gold modes act & perform similarly to the "all metal" modes of other manufacturers' detectors such as the Fisher F75. (For example, the only tone option is Voltage Controlled Oscillator = VCO.) Dave Johnson has used multiple terms to describe that kind of mode, including 'single filter' (see F75 user manual). In other words, it's as close to a raw signal as you can get if using motion to maintain stability. So that leads to the question: is this all the Equinox is doing in Gold Mode -- using the minimal amount of signal processing to keep the response stable? I can think of one filtering option available in the Gold modes which isn't present on traditional all-metal modes of other detectors -- discrimination/notching. But even for that, the F75 all metal mode has digital target ID readout so something is going on there, although in that case possibly in parallel.
  13. After a rather long hiatus (knee replacement) I finally was getting out to do a little detecting this weekend and found that my pinpointer had decided to go on a walkabout. Over the past few months I’ve directed several forum members to opportunities to purchase a TRX and now I needed to find one for me. Not an easy task. There is a used one on Ebay right now with bid already over $200 with five days yet to go….. OK, to the point of this post. Searching around I did stumble across a site selling TRX’s for $55 ea for a lot of 10 pieces, with about $150 for shipping (~$70 ea). Normally I would just move on assuming that this is more Alibaba/Aliexpress knockoffs but I decided to do a little more looking around. They list a fairly wide range of detectors and brands, including a number of MineLab models. My understanding has been that MineLab is very aggressive in shutting down dealers carrying counterfeits. Doing some online searching I didn’t find specific mention of counterfeit TRX’s, though plenty of discussion of Whites detectors, particularly the GMT. The Goldbug 2 and GPX 4500 were also quite popular. Here’s my questions. Do you think there is a possibility this may be a legitimate dealer? Last fall just after White’s announced their closing there were some dealers who were discounting their inventory before Garrett said they would be covering warranty issues. Does MineLab truly aggressively go after dealers selling counterfeits? How much mark-up is there on detectors, and could this be a dealer who is not following the pricing “covenant” or functioning as a middleman to smaller dealers? I will admit that prior to retirement I might have thought about taking a fly at these just for the hell of it, I’ve certainly taken bigger gambles (and losses) on gold stocks. At worst I may have been able to unload them as fakes that work as well as other pinpointers that sell in the $50 range – or just another bad stock investment. There’s always that risk when we buy anything used on EBay, Craigslist, Treasure Classifieds, TreasureNet , etc.,(i.e. the TDI SL I recently bought that wouldn’t ground balance and hopefully can be repaired), and I question the number of “new” gpx4500’s I’ve been seeing pop up in ads lately (really, how many people are going to buy one and then sell it unused at a significant discount?). Well, I’ll keep looking and hopefully a reputable dealer will find some hidden in their stockroom.
  14. Has anyone done a comparison of the mineralization readouts of various brand detectors on the same ground? I know Fisher F75 is considered a standard. I would like to be able to compare my NM Anfibio readings to other detectorist's ground conditions. F75, Deus etc. Also what GB settings others consider mild----hot ground.
  15. So I thought I would throw a spanner into the discussion. Here goes. We have heard of the double D coils what about a triple D coil. Well that outside my knowledge but let look at a quad D coil the oldest ground balancing coil. Have a look at these links.....LINK....https://www.phys.k-state.edu/reu2011/nnorvell/Metal_Detector_Research.html and more detail.....LINK....http://41.67.20.41/bitstream/handle/123456789/18621/Metal%20Detector.pdf?sequence=1&isAllowed=y Are we on topic. _________________ Regards Geof. geof_junk Contributor Plus Number of posts : 794Location : Gippsland AustraliaRegistration date : 2008-11-11
  16. 14" on a silver dime is the new standard. 10" was the standard and now it's 14". In Calabash's test videos: Anfibio hits it hard. Equinox hits it hard. Xp Deus a weak hit. Detectors are getting better. A new standard to hit or break for new detectors in 2021.
  17. Metal detectors aren’t just for hunting for gold. They’re also enormously useful tools for law enforcement. And yet, while most police departments have metal detectors on hand for crime scene investigation, far fewer have trained and qualified officers who know how to use them correctly. But when deployed properly, metal detectors can be a game-changer when it comes to effectively investigating a crime scene, uncovering evidence that might otherwise go detected while at the same time preserving a crime scene from disturbance. The evidence of metal detectors’ effectiveness is conclusive: A study published in Law and Order found that “Automatic Very Low Frequency (VLF) ground canceling metal detectors have proven to be the best all-around choice for ground (land) searches in law enforcement applications.” This was attributed to “their ease of use and sensitivity.” The use of metal detectors at crime scene investigations goes far back into history. In fact, a metal detector was used to uncover the round that was used in the assassination of President James Garfield. Safety is another factor when it comes to using metal detectors. To use an obvious example, consider a hypodermic needle in the middle of a pile of leaves. A metal detector can help an officer to discover such evidence without him having to root around in the leaves risking injury — or worse. When searching for weapons in a house, you can program a metal detector to ensure that it doesn’t read common objects in a wall or a floor. This makes it easier to find objects when they have been hidden with great care by a suspect. There are tons of reasons for police departments to have metal detectors and use them with vigor. What’s more, it’s probably less expensive and easier to both purchase and train than you probably think. Use It Or Lose It: Budgeting for a Metal Detector We spoke to former police officer Dave Bachert. Dave has over 20 years of experience as a police officer, having served in Allentown, Pennsylvania as the Supervisor of the Evidence Unit. While serving in that capacity, he went out and purchased a metal detector for his department. He notes that one of the first things he mentions to police officers with department purchasing power is that their budgets are, more often than not, “use it or lose it.” This means that the unspent budget will not rollover to the next year. And while many police departments find things to spend budget money on that are arguably frivolous, many don’t have metal detectors. So if there’s money sitting around at the end of the year — or even at the beginning — a metal detector is a wise investment that will not only uncover evidence that might otherwise go unseen but will also speed up the process of combing a crime scene investigation for evidence. Without Proper Training, Your Metal Detector Is a Paperweight Part of the reason that many departments don’t buy a metal detector or don’t use it is because they find the equipment to be intimidating. They might even have one, but no one wants to use it because they think it’s going to be too complicated and slow down the process. On the other hand, untrained officers using metal detectors might cease using them because they think that they don’t produce any meaningful results. But training to properly use a metal detector is not a difficult task and virtually any officer can learn how to use a metal detector properly. Most of the time the reason an untrained officer found no luck using a metal detector was because of some very simple mistake that can easily be corrected. Once learned, it is incredibly easy to use and will only serve to cut the amount of time it takes to investigate a crime scene while at the same time producing far more thorough results. If the department already has a metal detector, there’s little point in having it if it never leaves the office. After all, think about how much evidence you’re missing out on because officers aren’t bringing it out into the field to aid with their crime scene investigations? Proper training and knowledge of the equipment are crucial not only to detect and find evidence but also to make sure that the evidence, once found, will hold up in court. A skilled attorney can easily pick apart and discredit evidence found with a metal detector when the officer doesn’t understand the equipment or how it was used. On the other hand, an officer who is highly knowledgeable of and capable with his metal detector can withstand a great deal of scrutiny on the witness stand. This increases the chances of the evidence you find with a metal detector staying in the game when it comes to trial. Knowing the manual, learning the terminology and basic operation of the metal detector is the bedrock, but it’s not the end of the story by any means. There’s no substitute for practice with a metal detector. That practice doesn’t have to be, and ultimately shouldn’t be, limited to practice in the field. Officers should, for example, take a metal detector to the shooting range. This gives them the opportunity to examine a number of spent shell casings to learn the difference between how a metal detector registers one versus another. From there, officers can proceed to more complex tasks like finding shell casings and spent round that are underneath three inches of soil. This kind of training shouldn’t be an obstacle to getting the metal detector out in the field. It should simply be there to supplement what the officers are doing during actual crime scene investigations. Metal Detectors Are Snipers, Not Shotgunners Some might think that there’s going to be a lot of false positives when using metal detectors for a crime scene investigation, but this is not the case. Dave notes that a metal detector can be set so that it only detects the specific type of metal in the caliber of ammunition that you’re looking for. So, for example, if you know that you’re looking for a steel-cased 9mm round, you can set the metal detector to only report results for that type of metal. What’s more, you can set the bandwidth so that it isn’t reporting common items like gum wrappers that might set off a metal detector. One common method used when searching for evidence using a metal detector is to very narrowly set the metal detector so that it only returns results for a specific item that you are looking for. Once an area has been swept in this manner, an officer can then go over the same area casting a wider net. This allows for an officer to find specifically what he is looking for before searching the same area to see if there is anything that he missed that he wasn’t looking for. The gun range allows officers to acquaint themselves with the nuances of a metal detector. For example, what kind of alert does one get from a 9mm as opposed to a .40 or a .44 magnum shell casing? You don’t need a crime scene investigation to do this. All you need are a bunch of empty shell casings. Field experience, however, will be the gold standard when it comes to learning how to use the metal detector. While basically anyone can be trained to find empty shell casings and spent rounds, there’s a nearly unlimited amount of objects that could be found at a crime scene investigation that could end up being meaningful evidence. Indeed, as many crime scene investigators might attest, sometimes the most unassuming object can be a piece of evidence when the context is understood. Finding such “odd” objects in a crime scene investigation is more art than science. Officers will just have to learn how to separate the wheat from the chaff through direct personal experience using metal detectors on crime scene investigations. So what is a metal detector going to pick up at a crime scene that a trained investigator won’t? You’d be surprised. Dave reports finding guns and knives with his that investigators failed to locate on visual inspection of a crime scene. But beyond that, there are, of course, shell casing and even spent round that can be identified. This begins the process of forensic analysis of a crime scene. Once such a shell casing or a spent round is uncovered, laboratory analysis can begin to find out, with shocking specificity, precisely what kind of round it was before it was shot based on where contact with the primer occurs and what kind of rifling left its mark. This is a common method of matching guns to a crime, but it can’t take place if there’s no spent round or shell casing to examine. A car might not sound like a very difficult object to find, but it would be if it was buried deep down. A metal detector in the hands of a skilled crime scene investigator, however, can detect an automobile as deep as 20 feet below the surface. This will uncover evidence that virtually any crime scene investigator, no matter how experienced, would miss even upon close inspection of an area. Metal Detectors Help Preserve a Crime Scene Investigation Metal detectors also reduce the impact on and disturbance of a crime scene. When locating and acquiring evidence from a crime scene, even skilled investigators can find that they unintentionally disturb the area. This is especially common outdoors, where natural terrain must, almost by the very nature of the process, be disturbed while officers are looking for evidence. Metal detectors, however, can significantly reduce or even eliminate the disturbance of crime scenes. Officers don’t have to get down on the ground to poke around for shell casings — they can simply wave the metal detector over the area and it will let them know if the shell casing is there. It’s not just police officers who can assist with crime scene investigations using metal detectors, either. There are also legions of willing amateurs who are happy to help. Metal detecting clubs offer a ready-made army of amateur investigators who are willing to bring their tools to the search. There is some degree of training involved to ensure that the volunteers know how to not disturb crime scenes. But once you have these amateurs trained, you will be able to exponentially expand your ability to search a crime scene and uncover evidence. Underwater Crime Scene Investigation and Metal Detectors Another area where metal detectors can help is with finding evidence underwater. This is a particularly shrewd investment of time and money for coastal police departments. Finding evidence underwater can be a seriously Sisyphian task, often yielding little in the way of results. But with a water-ready metal detector in tow, it can be far easier to unearth useful evidence from a crime scene. Officers must be trained in the proper use of such, as should volunteers. But this training isn’t nearly as time-consuming as one might think. And once the training has been implemented it can be used time and again, paying dividends almost immediately. One way to explore an underwater crime scene without disturbing either the scene itself or the ecosystem is to deploy the search team, who then simply use little markers known as “pingers” to mark an area in need of further exploration. The area can then be handed over to people who specialize in this sort of excavation. Underwater metal detectors come in a variety of models, including ones for saltwater, which reduces the number of false positives. Others can be towed behind a boat, removing the need for skilled divers to investigate an area. Underwater metal detectors need to be specially designed so that they ignore things like saltwater and black sand, which can trigger false positives. But the right metal detector with the right settings in the hands of a law enforcement officer who knows how to use it will uncover objects underwater that likely would otherwise have gone undetected. Metal Detectors Help Solve Crimes When Other Tools Fail As amazing as it sounds, this type of physical evidence was once thought of as nothing more than mostly uninteresting useless debris around a crime scene investigation. But now they are much more easily connected with evidence from crime scenes. And while fingerprints are not a magic bullet, they can often be taken from shell casings. There are also serial numbers on all rounds made after the 1968 Gun Control Act, adding another means of tracing and tracking shells found at a crime scene investigation. How much can a little piece of metal found in a tree tell you about a crime? A heck of a lot, actually. Even a little fragment of a bullet has rifling details on it that begin to paint a picture of what ammunition was used. The caliber of a standard round or the gauge of a shotgun, for example. From here, skilled crime scene investigators can begin to deduce what brand of ammunition was used. This, in turn, begins to form a picture of which specific weapon was used when committing a crime. A metal detector can find spent rounds in places that even skilled crime scene investigators comb-over for weeks. Oftentimes, these can be found embedded into some kind of wood. But even knowing that, searching for the spent round is a bit like the proverbial needle in a haystack. Keeping with this analogy, however — it’s a lot easier to find a needle in a haystack when you have a metal detector to help you get the job done. What’s more, when a metal detector is used it allows for better preservation of the area where the spent round is found. Thus, two pieces of evidence can be yielded through such methods. There are rather astonishing real-world cases of forensic analysis matching up a weapon to a spent round or shell casing found at the scene of a crime. A man who was known to Philadelphia police as the Ruthless Robber was a dangerous menace who would rob his victims, then shoot at them after they had handed over their valuables. And without the kind of forensic evidence we’re talking about here, they never would have matched up one of his shell casings to a weapon that was recovered at a totally unrelated traffic stop. In another case in Phoenix, Cleophus Cooksey Jr. was arrested for a double homicide. Within 48 hours they had him tied to seven other homicides, with police confident that they had caught a budding serial killer before he had a chance to really hit his stride. Finally, there is the case in Colorado Springs, where a police department was having a bear of a time solving a series of crimes in the area, including a drive-by shooting at a local mall. What police were able to deduce from a large number of shell casings and spent rounds paired with forensic analysis is that several gang members were sharing a single “community gun.” Without a large amount of data to work with, there is no way that these homicides would ever have been solved. The point here is that the more evidence you can collect, the better. While what you find might not be completely germane to your investigation, it might be helpful in another one. This is especially true if you live in a state where you have access to a statewide database of spent shell casings. And with a metal detector, you are certainly going to uncover more pieces of evidence with less crime scene disturbance than you would without one. Another example of the role that metal detectors can plan in getting a conviction is the common pastime of joyriders shooting at stop signs. The recovered shells from such incidents might not attract a lot of notice without forensic analysis. However, with forensic analysis, police departments can begin matching the spent rounds and shell casings up to much more serious crimes that are oftentimes totally unrelated. There are sweeping changes happening with law enforcement thanks to the revolution in forensic analysis. It was, and to a certain extent still is, uncommon for police to be able to solve non-fatal shootings. This is because of the amount of time, energy, and resources that have to go into these cases that oftentimes are better spent on fatal shootings. Modern forensic analysis, however, makes it much easier to get the information needed to get a conviction from a piece of evidence such as a single shell recovered at the scene of the crime. A metal detector, in the hands of an officer properly trained on how to use it, will help to expand the evidence pool, allowing for greater convictions of all crimes, non-fatal shootings included. What’s more, the man-hours involved in collecting evidence from a non-fatal shooting is significantly reduced when one has a metal detector on hand. The technology works from both directions to make investigating non-fatal crime scenes much more appealing even to smaller police departments with modest budgets: Better forensic analysis makes it easier to use the evidence provided, incentivizing collection. Better tools, such as metal detectors, make it easier to collect evidence in the first place, making the barrier to going out and collecting evidence lower. But the important thing to remember with all of this is that there has to be proper training. Training isn’t complicated or arcane — if you made it through the police academy, you can learn how to properly use a metal detector. But the training has to be done right at the beginning to ensure that officers are finding what they are looking for and not becoming frustrated by a series of false positives. Once this training is done and the metal detector comes into common use during crime scene investigation, officers will likely wonder how they ever got by without one in the past. Crime Scene Investigation and Evidence Collection originally appeared on kellycodetectors.com
  18. Hey guys, Can someone explain to me in simple terms what is it and what we accomplish by using a slight ground balance offset (either positive or negative) on our machines? I remember for example that when using an Xp Deus in the past, whenever I needed some little extra depth boost I was manually set the GB a little lower than the actual ground phase of my area but in the expense of greater ground noise and instability...the opposite when I needed a more quiet run....However I never deep dived into this concept and never understood how and why this really worked. Would be great to understand this now, and in order to help me (and because each machine has a different GB scale), let's assume a Ground Balance scale of a Makro Multi Kruzer (which I'm expecting soon). So...In a Makro M. Kruzer, let's say that machine grabs (via pumping) a Ground Phase of 70 in our area... 1) What if I manually set my GB slightly HIGHER than 70 (eg at 75) regarding ground noise, depth abilities and targets detection? Will the effects be the same for both low & high conductors or tiny & large targets? 2) Same as above, what if I manually set my GB slightly LOWER than 70 (eg at 65) regarding ground noise, depth abilities and targets detection? Will the effects be the same for both low & high conductors or tiny & large targets? 3) Will this GB offset apply also in the salt water the same way? (I recently whatched a guy reviewing and using a Multi kruzer in the salt water, and he manually increased his GB value on purpose while he was trying to detect a small gold chain underwater...never understood why he did such a thing and how this works) 4) Lastly, please define which side is "positive GB offset" and which side is "negative GB offset" in Makro machines..... May sound obvious but, in some machines higher GB Phase means hotter ground but in some other machines higher GB Phase means milder ground (the opposite). So to tell me that "a Positive offset means moving the GB value to the hotter side of scale & the effects wil be that..." may mean nothing if I don't know which side is hot and which side is mild...hope that makes sense. I don't have a clue which side is hot & which is mild in Makro GB Scales so would be nice to enlighten me and correlate your answers with this! Hope my questions makes sense... Regards, Argyris
  19. Greetings fellow detectorists, I'm hoping someone with a deeper understanding of the technological methods of the Equinox series might be able to shed some light on why certain Interrogation methods work they do. I think we are all aware of the little trick whereby a potential target in the mid conductor range in multi frequency can be examined in 10hz; a sudden jump from the teens to the twenties indicates a likely bottle cap. My questions are two fold; first, what is responsible for this phenomenon? Why does a change in frequency potentially change the vdi of a target, and what determines when a change occurs? Second, is there a potential logic here that one can use to devise further Interrogation methods using similar principles? Looking forward to your insights!
  20. In addition to nugget hunting I am also a history buff and I would like to learn more about metal detector technology, its history and sequence of development. I understand that the BFO (Beat Frequency Oscillator) technology was used in the very early metal detectors. Right now I would like to learn what is the difference between TR (transmitter receiver), induction balance, and VLF technologies and when was each one introduced to the market. Is there anywhere where I can find a list of manufacturers, the models (technology) they offered and date range they were offered? I have searched the forum without success. Is there a link to a thread or article that I have missed? Thanks in advance for your help.
  21. Winter will be starting to set in soon, and cabin fever will soon be running rampant , time to think about the next dream machine from Minelab. What improvements would you like to see over the Nox 800? Preformance is always a biggie. More depth, more Stable ID at that depth. Wider numerical ID system, 0-100. Better selection of optional size coils. Or, maybe an etrac or explorer features in the nox liteweight style? Adjustable handgrip pod. EMI elimination system. If you request it, maybe they will build it. 😁
  22. (Long article. If you think you'll get bored of the background info and stop in the middle, skip to the Testing section to see what a metal detector has to say.) Introduction Detectorists occasionally come across ceramic tableware/dinnerware at sites. For example, I found some in a ~1880's Colorado ghost town. A friend of mine found a piece (which I was able to identify and date to the 1890's) near a high altitude Colorado miner's cabin associated with a small silver mine. Western USA explorers/settlers/miners may seem backwards and uncivilized (and that is true in some cases) but often they longed for the finer things of the lives they left behind. Ceramic dinnerware was both utilitarian and aesthetic. Coin&relic detectorists around the world use pottery and other ceramic pieces, often found on the surface, to indicate good places to detect. In a previous life 😁 (actually 1998-2015) I was a avid (make that obsessed) collector of dinnerware by a particular USA manufacturer, accumulating a collection of 2000 pieces by scouring antique malls/shops but also occasionally other sources like rummage sales and Ebay. Not surprisingly I did a lot of research on the subject during my collecting years. Here are some results relevant to metal detecting. Plausibility In this first photo are two 6" diameter plates, both with filigree decoration and an edge line. The lower decoration is gold and the upper one is platinum (often mistakenly but understandably called 'silver'). The upper piece was manufacture in 1937 and the lower (gold) one in 1952. Each sold (usually as part of a set) for considerably less than $1 -- let's use $0.20 as a reasonable amount. Can we possibly reconcile these two 'facts' -- precious metals on inexpensive items? It is known that gold can be worked into very thin sheets. According to Wikipedia, typical gold gilding is 100 nm thick. ('nm' is the abbreviation for nanometer. There are a billion nm in a meter.) Scientists in the laboratory have done ~200 times better -- less than 0.5 nm which is actually about 2 gold atoms in thickness! Coatings on precision mirrors (e.g. astronomical instruments) are also about 100 nm in thickness -- same as fine gilding -- and that is thick enough to reflect in the high 90% decade at infrared wavelengths. About 15 years ago I took a tour of the Homer Laughlin China factory in Newell, West Virginia -- located in the very tip of that spike in West Virginia's NW part, along the Ohio River across from East Liverpool, Ohio and about 45 miles WNW of Pittsburgh, Pennsylvania. They actually took us to the factory floor and one of the things they showed us was a technician/artist painting the gold edge line on a piece. The claim was that it was pure gold (24 kt) but my research indicates it was more likely 22 kt. I calculated the approximate amount of gold on the edge line of the lower plate in the picture above and at today's price ($58.54/g) it comes out to about $0.06 worth. However, when that piece was made, gold was $35/oz (a factor of ~1/60 compared to today) so that material cost would have been more like $0.001 (at tenth of one cent) for a 6" plate. That certainly seems plausible, even if the thickness was several times that 100 nm assumption. Testing I used the Minelab Equinox 800 with 11" coil, Park 1 mode, gain of 24 in 10 kHz, 15, kHz, and 20 kHz modes (MultiFrequency too noisy with EMI) to see if the following soup bowl would give a signal. This is a rather extreme example in terms of the amount of platinum for an inexpensive piece of dinnerware to contain. The platinum band is 1/2 inch wide (1.27 cm) and the total calculated mass is about 0.011 g (assuming 100 nm thickness of pure platinum, so adjust accordingly). At today's price of $36.49 g those assumptions translate to $0.40 worth of platinum in this dish (I don't know the platinum spot price when it was manufactured in 1932). The digital Equinox's TID waffled between 1 and 2 and the signal strength was maximized when the coil was centered over the dish, with the coil about 1 inch above the platinum band, resulting in 3 arrows out of 5 ("depth meter" reading). Sweeping over the entire dish also gave a weak hit when the edge of the coil crossed the edge of the band. I also tested a similar sized dish which had just an edge line and filligree decoration similar to those shown in the first photo. There was no noticeable response by the detector on that one.
  23. I noticed early on that in discussions about the conductivity of gold, that gold is considered a low conductor. This is confusing to me. My understanding was that gold is a high conductor, whereas only 2 other metals are higher conductors. Silver being the highest conductor, and copper being the next highest, allowed by gold. Iron is way down on the list. Can anyone please explain this?
  24. Found some clubmates discussing who (and when) invented the first pinpointer. Google just found some hints. Feel free to discuss...
  25. Years ago I had a wise customer who was always trying to make things better. He spent much of his free time chasing gold nuggets at Rye Patch, NV in the 90's and early 2000's (when pickings were good). He always wanted to cover ground and chase the big ones. One time he calls me to order some Coiltek coil wiring (extension) as he has long dreams. I seen him out there with his new long shaft and boy was it longer than I had expected. Has anyone seen anything similar or just as crazy? On a side note, this beautiful Horse Nugget of 6 ounces was found in the road at Rye Patch proper. Seems most of us had walked over it for years thinking a beer can in the middle of the road when in fact it was the biggest piece of gold I have seen come from Rye Patch. I know one of my Staff found a 5+ oz'er one time and Chuck/Gracie from TX showed me a 5 oz'er, but this one has character. If anyone knows of bigger gold nuggets from actual Rye Patch proper or of a longer shaft on their Minelab, I'd love to see. Enjoy everyone and stay out of my swing path, all 30 feet of it.
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