Jump to content

Search the Community

Showing results for tags 'detector tech'.

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Metal Detecting & Gold Prospecting Forums
    • Meet & Greet
    • Detector Prospector Forum
    • Metal Detecting For Coins & Relics
    • Metal Detecting For Jewelry
    • Metal Detector Advice & Comparisons
    • Metal Detecting & Prospecting Classifieds
    • Compass, D-Tex, Tesoro, Etc.
    • First Texas - Bounty Hunter, Fisher & Teknetics
    • Garrett Metal Detectors
    • Minelab Metal Detectors
    • Nokta / Makro Metal Detectors
    • Tarsacci Metal Detectors
    • White's Metal Detectors
    • XP Metal Detectors
    • Metal Detecting For Meteorites
    • Gold Panning, Sluicing, Dredging, Drywashing, Etc
    • Rocks, Minerals, Gems & Geology

Categories

  • Best of Forums
  • Gold Prospecting
  • Steve's Guides
  • Steve's Mining Journal
  • Steve's Reviews

Categories

  • Free Books
  • Bounty Hunter
  • Fisher Labs
  • Garrett Electronics
  • Keene Engineering
  • Minelab Electronics
  • Miscellaneous
  • Nokta/Makro
  • Teknetics
  • Tesoro Electronics
  • White's Electronics
  • XP Metal Detectors
  • Metal Detector Settings

Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Website URL


Facebook


YouTube


Instagram


Twitter


Pinterest


LinkedIn


Skype


Location:


Interests:


Gear Used:

  1. From what I can gather, higher frequency VLF detectors are more suited for smaller gold but ground mineralisation may be something to factor in. Would there be a “better” frequency for nuggets 1 gram and above in heavy ground? I’m not too concerned if I miss sub gram nuggets if there is a better suited frequency. The old Garrett Groundhog circuitry was legendary in this country…..I think it was around the 15 kHz mark. Is this frequency range a good starting point or do I need to consider other things such as better ground balancing capabilities or Garrett’s extra coil voltage. My Minelab PI units will be mainstay detectors but as mentioned in another post, I have ground littered in man made iron junk and the ground mineralisation is severe. There are plenty of nuggets in the 1 gram to 5 gram range (maybe bigger) but the iron signals are as dense as 5 per square metre 🤬 Thanks for any ideas.
  2. I’m a newbie and saving up to buy my 1st metal detector. Meanwhile I’m rockhounding a lot. I’m curious if folks have successfully applied portable ground penetrating radar (or other portable detecting devices) to predict likely location of crystal pockets in the hard rock, like in dolomite (for locating pockets of Herkimer Diamonds) or in granitic pegmatite (for locating pockets of gem tourmaline crystals) ? Any pointers would be appreciated.
  3. maybe we could have a multi frequency coil, that recieves a single frequency or selectable single frequency and effectively distorts and amplifies the single frequency resulting in frequency variants up and down, mimicking or creating smf
  4. Norvic asked why I was so proud of a VLF when I own and have posted much success with the other higher end detectors. It was my post on rating the higher end Minelabs....so here goes. There are many factors to my craze and style of detecting, but my finds are the facts and not many people can compare, unless they too use the tools (detector) and hunt the style I do. I consider myself a gold hawg or gold pig. I chase it all in terrains flat or tall. Terrain - I live in the Northwestern state of Idaho and much of my detecting in the surround state of ID., is Oregon, Nevada and occasional Montana. For the most part, OR, MT and ID are pretty much the same with steep terrain mountainous rough country. A day of electronic prosecting and hiking in such states, is much harder on the body for a guy my age, heck it’s harder for anyone. Going to Arizona, Rye Patch and other Northern Nevada high desert areas is a treat for my body in more ways than one. Maybe that is why so many people detect there? It’s easy to drive and get to without walking…boy are most of us lazy? YES, including me at times, but not in my home state (backyard where I play). The ID, OR, MT mountains have steep ravines/canyons and the water is at the lowest point. Here is the many miles of hand placer workings, dredge tailing and hardrock mining ore dump piles. The gold I am chasing is the stuff the old timers missed. Pic below - This huge ore dump pile produced a few thousand dollars in Specimens. This is the not so steep side and we had to tie off with ropes on the other side. Half the targets would roll down the hill and need to be found during a break when we were at the bottom. The PI's can't see this time of gold. Trash - Trash is my treasure in a way.. as I know the site has not been hunted as hard. Trash is what most detectorists hate, and I too get that way on occasion, but I know if I'm patient, I'll eventually be rewarded. A big factor I run into is 100 to 150 yr old man made trash from the early prospectors. They left much of it on the hill, in the placer digs and tailing piles. Many of the small mining camps were right on or near their diggings and they just tossed the old food cans, tobacco/coffee tins and worn out leather boots with hundreds of nails and broken, picks/ax heads shovels aside. Pic below- In old tailing piles a lighter, faster, better ID detector is best. He who digs the most non ferrous targets in a day, get to smile all the way home. Pic below- is the 1 pound specimen after cleanup. Tools – Know your detector, its limitations, strong and weak points. Bigger deeper detector is great in flat terrain and areas with limited trash. Raw depth and power is amazing to have, when the target you dig a foot or so deep is not a sardine can. How about a shovel head at 2 feet or more? Think about it and what you do when digging 5 or 6 of those an hour with your big deep penetrating detector. What does your body have left in the tank? My lighter VLF is easier to swing in rough terrain, has better Iron and Target ID, is not as deep or powerful in trashy sites. It saves me time from digging unknown iron targets, it saves me energy from digging deep holes, it saves me energy from having to pack around a bigger bulky detector. The proper detector for the site is a must and in many cases my lighter, faster, better target Identification, sub $1000 investment is the right tool. Pic below - This golden oreo was recovered in old hand placer workings with my VLF. Having what I consider the best identification VLF gold detector on the market saves me time. Pic below - It was recovered at 16" with Minelab EQ-15" coil. Yes I'll be going back over this area with the new CoilTek NOX 15" round as it is even deeper. Gold Knowledge- This is confusing to so many people as they think gold is gold. Yes I too used to think the same way. Luckily I hunt a variety of gold producing locations and sites I like to detect and learn from. My many years of comparing/testing detectors at such sites has given my staff and I an understanding of gold, its characters, density and how the elusive Au responds to the varying detector models from the different manufactures. Many of the nugget photos being shared on social media in years past were dense solid gold pieces and they are beauties. That’s what the detector could easily respond to. In more recent years, the sizes of the nuggets became smaller and we started reading about and seeing some nice specimens. The newer GPX detectors with their advanced tuning and soil timings (Fine Gold) would outperform their older brothers (SD/GP’s) on smaller and courser gold, so when get to make more of those finds and share them. Most recent years has us using SDC-2300 and GPZ-7000’s. Again, the gold gets smaller and the amount of crystalline gold, wire gold, salt/pepper specimens are being unearthed with these detectors supersedes that of their older brothers the GPX series. Pic below - This softball sized specimen was found with a VLF and has multi ounces of gold. VLF picks it up deeper than many bigger detectors. Pic below - This beautiful 3" long quartz and gold specimen came from a trashy ore dump pile with a VLF. Pic blow- These quartz cocoon wire gold specimens bring a premium and come out of hard rock ore dump piles. Pic Below - The PI's don't see these rare pieces, the 7000 barley does on a select few. Pic below - I have a feeling the extra sensitivity of the new GPX-6000 will do even better. Proof – The facts are in the vault at the bank. I own beautiful specimens pieces recovered with detectors and have tested many on a variety of detectors. I have gold finds that are multi ounce pieces and they contain 2 or 3 ounces of gold in them, but for some reason an SD or GP don’t see them, even less than an inch. I also have such pieces my GPX 5000 does not see, but my GPZ-7000 does. What is most amazing, is I have pieces of gold with multi ounces of metal and even the ZED has issues or can barely respond an inch or two away. If this is the case, then why do I have these find gold pieces of art? I’ve taken the time to test and learn my detector tools and have found a certain trusty VLF sees them all, can ID them all, is lighter in weight and so I get to hunt longer, saves me energy since I don’t dig as deep for unwanted targets. Pic below - This specimen came from dredge tailing and the speckled pieces like this get missed by most PI's. Pic below- Over $800 in gold in this 3 ounce specimen and my VLF does better than my GPX-5000 and my SDC-2300. The SDC goes deeper than the GPX. You better know your gold and your detectors capabilities or lack of. Pic below - This 3 ounce specimen was found in trashy hand workings. I actually had a GPZ-7000 here for a couple hours and gave up because of the amount of item trash. A GPX-5000 with DD coil run with DISC mode would be better than my GPZ, but then again my NOX does even better. Better target identification of my NOX, is most important at the site this 3+ oz'er came from. GPX-6000 – A new tool and one that has Gerry very very excited. Now we are about to get a revolution of Geo Sensing Technology with PI power and capabilities for a wider variety of gold textures, densities, characters and sizes. Minelab (and their track record) is even telling us some of such capabilities and so I and a few of the guys who do not like to miss gold, are getting ourselves prepared, getting our old sites, lined up and making sure we are going to take advantage of the stragglers. Remember when the SDC-2300 and GPZ-7000 came out and all the slow response from the majority. You folks missed the opportunity of a lot of gold. My guys and I were killing it in NV and AZ on those so called worked out sites. Was it a gamble to spend that kind of money? If that’s what you love/enjoy and if you have a good track record with Minelab, it’s bet I’ll take most every time. I don’t lose detector bets very often. Pic below- This stunning collectible specimen was found by my brother with his SDC-2300. It came from a place he had previous hunted and found gold with his GPX-5000. The 5000 does not even whisper on it. Minelab claims the GPX-6000 is more sensitive than the SDC-2300 & GPZ-7000. I can't wait to use the GPX-6000 at the site and many others. Hopefully this story and the pics I shared will help educate some of you on how the different detector technologies produce more gold. I realize it's hard to put down your old reliable detector as it has probably and hopefully served you well. If your sites are getting thin of targets and or gold, just maybe a new detector can put the smile back on your face? I'll go back to this simple statement I have said below in other posts and it is the absolute truth. You can't find what your detector don't see. PS - I’ll be honest though, for me it’s the lighter weight, better ergonomics, not being tethered in a harness and User Friendly that has me sold. The extra gold my new GPX-6000 is going to find, is a bonus. PPS – I’m just as eager to test the GPX-6000 with some of my gold and see how much better/worse it does than my GPX, SDC and GPZ. (I'm educating myself). PPPS – I still feel there will be a place for my VLF, as it’s lighter, and have better target ID. See you in the gold field, where the most knowledge is learned. Or speed it up with our 3 days Field Training at www.gerrysdetectors.com Happy Hunting. Gerry
  5. After the good new I realized when tested a few days ago my machine after It drowned and I've succesfully reanimated It.... Now the horrible gasket Is fighting to stay out of the housing against any kind of attempt😒. So I'm in the middle of a headache manutention session with scarce results. That's the Mood guys😑
  6. So Im curious... with Makro/Nokta we saw a ton of You Tube videos on the Kruzer in various settings. Even Dilek posted on the machine on the forums before it came out. Even the AT Max we say a little here and there on the unit. Where was the early info on the Equinox? I know there was/is a "gag order" in place, and boy did they do a good job... not a word from anyone hardly! But when does the gag order lift? 1 year, 10 years Never? I'm interested in the "seasoned" testers that were able to use early models. These early thoughts to me are a real gem on what was changed, improved, altered. Any ideas?
  7. Don’t know any other better subforum to place this. When manufacturers design make sure platform can allow at least 2 software versions or at the very least allow what I call both newer version update (whole) and a older subset (portion of older version) to be used. Why? Makes testing easier if and when a newer version is designed and requires pre release testing in the field for validation. Would allow users after version release to use different versions and gain first hand feedback of the benefits or lack thereof of different versions or version subset(s). Case in point. Notice Minelab left old iron bias to be user selected when they released newer version with iron bias F2 option. So in a nutshell this allows the detector versions ( or version subset) to be compared to the themselves in the field by the user. Xp should have done this too. They should have designed Deus imo where at least 2 complete version allowed to be uploaded to unit. Notice the later released Ace Apex. Garrett should have allowed on it too. Don’t know what added production cost this would cause. Hopefully not much.
  8. See NASA-Tom’s comments https://www.dankowskidetectors.com/discussions/read.php?2,181189
  9. 99% of my detecting is done on central Florida beaches. Since it’s impossible to establish a well stocked test garden at a public beach, I sorta brought the beach home with me and developed my own private beach garden! I cut slots in two large empty chlorine tablet buckets at various depths as shown from 2 -16 inches. I then filled one with New Smyrna Beach sand and the other with soil...for the few times I land hunt around here. I embedded numerous examples of ferrous and non ferrous targets into paint stirring sticks. I also have several blank sticks I use for gold and silver jewelry as well as artifacts that I don’t want permanently attached to a stick. I then insert the target(s) in the slots, each at its desired depth, and start scanning. This allows me to rapidly change the targets, depth and relative position of each. I can now test for sensitivity at depth as well as separation of ferrous and non-ferrous targets in a variety of scenarios using actual beach sand where I do my detecting. If I want to test in wet salt sand, I just soak the bucket sand with authentic sea water that I also brought home from New Smyrna Beach...and the Atlantic Ocean never even missed it. 😉 Works for me.....
  10. I'm looking for a Compass metal detector catalog that includes the Compass Gold Scanner, and Compass Gold Scanner Pro models. The full line catalog, and this would be about 1990-1992 or thereabouts. I'm adding a few key older metal detector catalogs to the Downloads Area to provide basic info on older models. I do not need a ton of catalogs, just key years where major model changes occur, as things moved slower back then. If the catalog was in pdf format that even better, but Googling only turns up a couple older catalogs, nothing I can find covering the Gold Scanner era. I am more than happy to pay for a print version if need be, so I can scan into pdf and put up for people to download. Thanks in advance for any help. Me and my Compass Gold Scanner, back around 1990:
  11. This was mentioned by geof_junk in another thread and had a little Google. Found this https://www.phys.k-state.edu/reu2011/nnorvell/Metal_Detector_Research.html I don’t really understand the technical side of metal detectors. Does this have any application to current day detectors? Will it help cancel out ground noise more? Will the current crossing/not crossing the ‘bridge’ tell you something about what is under one of the receive coils. Although I don’t understand it, I am amazed and a little in awe of those that do 👍
  12. This is a topic relevant to every(?) form of detecting -- ground coverage. I'll list several questions concerns I've had but any replies of course aren't limited to these, nor do they need to address any of them. Just tossing out some ideas to prompt further discussion. 1) What methods and efforts do you apply to ensure full ground coverage in the cases where that is one of your goals? 2) Is your sweep a straight line path or an arc? 3) How long is your sweep? 4) How much do you overlap consecutive sweeps in the direction you walk? 5) How much do you overlap side-to-side swings when following parallel paths (e.g. when walking two side-by-side swaths in the same direction how much does the left end of one path overlap the right end of the next path or vice-versa)? 6) Have you ever measured your coverage? How well do detectors with GPS (e.g. Minelab GPZ-7000 and Minelab CTX-3030) monitor ground coverage to this detail? Have you used other devices to measure ground coverage. E.g. I can imagine a drone with camera could provide useful data. Are there smartphones app that would help quantify coverage?
  13. If this question has been addressed elsewhere, I apologize in advance and hope someone can give me a link for it. I have noticed that other companies besides Minelab are coming out with PI detectors for less than $3K. How do these detectors compare to the best Minelab detectors for Gold and also relic hunting?
  14. Just dreaming... What'dya think? Minelab technology going on the next moon mission? X6 must be space-worthy.
  15. 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.
  16. 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?
  17. 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.
  18. 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?
  19. 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?
  20. 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.
  21. 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.
  22. 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?
  23. 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
  24. 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...
  25. 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
×
×
  • Create New...