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Found 289 results

  1. I do what I can to foster competition that develops alternatives to the all too common VLF detector. There are plenty of options out there, but in my opinion they all weigh too much or cost too much. Usually both. I envision people out there with a popular VLF metal detector for beach, relic, or gold detecting. These machines all sell for around $700 and weigh 2.5 - 3.9 lbs. Perhaps they would like to add a ground balancing PI (GBPI) to what they have. I think that for "normal people" with normal budgets a machine under $2K and under four pounds just makes sense. It would be more than twice what they spent for their VLF, and in this day and age there is no reason why a decent PI should weigh over 4 lbs. To clarify what I am talking about here, I should say that for many people a $700 VLF detector is a great place to start and in many cases is all a person ever needs. However, there are places where extreme ground mineralization and mineralized rocks (hot rocks) severely impede the performance and use of VLF detectors. Alternative technology to deal with these conditions has been developed, by far the most familiar being the Minelab ground balancing PI (GBPI) detectors. These differ from common PI detectors by having the ability to ground balance. Other brands have offered the Garrett Infinium (discontinued) plus Garrett ATX and the White's TDI models. These detectors are used not just for gold prospecting but also by relic hunters, beach detectorists, and others who face challenges regarding ground mineralization and VLF detectors. Frankly, in my opinion GBPI technology is largely maxed out. The main room for improvement comes now in better ergonomics at lower prices. This challenge therefore limits detectors to those that weigh under 4 pounds with battery included, and which sell brand new with warranty after discounts for under US$2000. Detectors need not be ground balancing PI models, but must offer similar ability to ignore mineralized ground and hot rocks that trouble VLF detectors. I am going to rate detectors as to their relative performance using what I call the "Minelab Rating Scale. Details here. 1. Minelab SD 2000 - crude first version, very poor on small gold, excellent on large deep gold 2. Minelab SD 2100 - vastly refined version of SD 2000 3. Minelab SD 2200 (all versions) - adds crude iron disc, ground tracking 4. Minelab GP Extreme - adds greatly improved sensitivity to small gold, overall performance boost. 5. Minelab GP 3000 - Refined GP Extreme 6. Minelab GP 3500 - Greatly refined GP 3000, last and best of analog models 7. Minelab GPX 4000 - First digital interface, rock solid threshold 8. Minelab GPX 4500 - Refined GPX 4000, solid performer 9. Minelab GPX 4800 - Released at same time as GPX 5000 as watered down version 10. Minelab GPX 5000 - Culmination of the series, current pinnacle of GBPI prospecting machine technology. All Minelab models leverage an existing base of over 100 coil options from tiny to huge. I am a very practical person when it comes to detecting. I know all the existing models and options by all brands very well, perhaps better than almost anyone. This is the way I look at it is this. If I personally were to spend a lot of money to go gold prospecting for one month, and needed a GBPI detector, considering machines past and present, what would I get and in what order of choice? Put aside concerns of age, warranty, etc. just assume functioning detectors. Here is the issue in a nutshell. On the Minelab scale of one to ten as listed above, I would be generous in rating the White's TDI SL as a 2. Same with the Garrett Infinium which I will mention in passing as it is no longer being made. If I was going to spend a month of my time and a lot of money going on a prospecting trip, I would choose a TDI in any version over the SD 2000. I might go with a TDI Pro over a SD 2100 but I would have to think real hard about that, and when push comes to shove I would go SD 2100 were it not for the realities of age I said to ignore. A newer TDI Pro might be a better bet than a very old SD 2100 from a reliability standpoint, but again, this would be a tough choice. The TDI SL not really. In my opinion I would be shooting myself in the foot to go on this hypothetical trip with a TDI SL instead of a SD 2100. You see the problem now? The Garrett ATX fares better. I would rate it a 3, roughly analogous to the SD 2200 variants. Still an agonizing choice really and the ATX being new versus SD 2200 being old might again be the tipping point, but from a pure prospecting options perspective the case can be made that the SD 2200 might be the better way to go. The problem for this challenge is the ATX weighs way over 4 lbs and sells for slightly over $2000. The price is close enough really but the 7 lb weight is way off. That's it folks. That is reality. The best of the best that the competition can offer can only go solidly up against models Minelab has not made in years. I am not saying that to be mean or as some kind of Minelab toadie, that is my pure unvarnished opinion as a guy who is pretty well versed on the subject. Let's bring it all home. This person with the $700 machine really, really wants that under 4 lb, under $2K GBPI machine, but if they do their homework they discover that truthfully, they would be better off shopping for a used Minelab than what the competition offers new. With the TDI SL rated as a 2 the ATX in a much lighter box at under $2K is a solid win as a 3. A well designed ATX with standard dry land coils would look very enticing as compared to the GP series Minelabs. But Garrett refuses to budge! White's can certainly do something, anything to improve the TDI SL. A battery that lasts all day would be a good start. In the end they are limited by the basic single channel design of the machine. The SD 2000 dual channel design was literally the answer to and the improvement on the single channel technology used in the TDI, the basics of which predate the SD 2000. Still, White's currently owns the under 4 lb under $2K GBPI category so they have the first out of the starting gate advantage. Anything they do would at the very least just show they have not given up. The Minelab MPS patent that formed the basis of the SD series has expired. Not sure about DVT, which formed the basis of the GP series. Where is the competition? What the heck is going on here? Much gnashing of teeth and pulling of hair is going on here, that's what!!! That is my challenge to the manufacturers. Under 4 lbs, under $2K, on the 1-10 scale I am offering, what is the best you can do? The TDI SL as a 2? Really? Yes, really, that is currently the best of the best in the brand new ground balancing PI, full warranty, under 4 lb, under $2k category. You can pick up a 3.5 lb TDI SL right now brand new for $1049. The White's TDI SL takes the crown. Note that a challenger has a half pound of weight they can add to the TDI SL and still make the 4 lb mark, and retail can be almost double the $1049 of the TDI SL and still come in at the 2K mark. I therefore do not think my challenge is outright crazy. Hopefully we will see more competition in this wide open category soon. I have been beating this drum for years to no avail, but I do have reason to believe we are finally going to see more alternatives soon. I hope. Maybe? White's Electronics TSI SL metal detector
  2. I am somewhat new to metal detecting and was recently told, by a veteran detector, that all machines are multi frequency. I was also told to not buy into the multi frequency hype and that machines advertised as ones, is a marketing ploy. Please help! Is he right?
  3. Is this detector able to detect diamond? I am trying to find a diamond from a ring that fell out a number of years ago in my garden. My friend Aberal Molzesman said in his blog tha it is possible.
  4. I am new here so there may be a better forum to ask this question so redirect me if needed. I have a Teknetics Delta 4000. I need to probe a fiberglass tube 2 inches in diameter to see if I can detect a copper beryllium strip which should be inside. Unfortunate I cannot get closer than 16 ft to the tube. I have found a 25 foot 5 pin DIN cable that would extend the cable that is on the 4000. I could then detach the pickup coil and mount that on a 16 ft PVC rod leaving the electronics and readout with me. I only need to know if there is something there or not there. The rod is 100 ft off the ground and 16 ft out from my closest reach. Anyone ever tried to extend the cable?. I know it is not a perfect situation but I would save me a lot of money if I can detect the metal strip. Regards Mike
  5. How good is this for our hobby? From looking at new members each day here and other forums seems to be a lot of newbies. They have a bunch of great choices that won't break your bank account. They can pick from the Garrett Ace line, AT Pro, Nox 600 & 800, Simplex+, Vanquish series, the new Garret Apex and maybe several new detectors from Minelab next year. Maybe some old times can tell us if there was a similar period of great detectors to pick from.
  6. Looked interesting enough to share https://hackaday.com/2020/05/02/a-smart-diy-metal-detector/
  7. What machine that you were able to use at a certain time gave you an advantage over others at certain places you hunt.The first for me was having a minelab explorer in Jan of 2000 for hunting coins in parks. Even being too selective when I first started hunting with it I still cleaned up because the machine was that good. The problem was there were many good explorer users in my area which made it much harder to find coins like we did in the past with such ease.The Nox is a great machine but it was not available in( 2000- 2007 ) when the explorer ruled the parks.That machine and that time will always be special to me.Mike Moutray who was one of the best explorer users I saw would go around the country and would hunt places people on the forums would take him to.My friend got in touch with him and he would hunt a old racing track with us . 6 explorer users in all.He made the most finds out of all of us.He was that good.Yet he hunted 3/4 of a 200 year old oak tree and went to the bathroom. When he came back he did not go back to finish the tree. I went to the tree and got a iffy deep hit and dug,putting the dirt in a gold pan.Out came a 1909 2 1/2 $ gold coin.I then put the Sunray probe in the hole and got a pulltab hit.Out pops a other 1909 2 1/2 $ gold coin.Put the probe in the hole and again a pulltab hit. This time a fired 22 slug.The song says 2 out of 3 aint bad.The explorer was way ahead of its time.
  8. Okay all you propeller heads...... When it comes to PI detector power, it’s Amps that matter first.....correct ? Minelab PI’s: Operate around the 7.2v but draw close to an Amp White’s TDI: Operate at 12v to 16v but draw about half an Amp So voltage is “electrical pressure” but Amperage is “the rate of electrical flow”....... What controls the Amps........just the MOSFET Steve......didn’t know where to post this question so feel free to move as needed. Thanks Tony
  9. I have the Simplex + and thinking about buying the Vanquish 540 but do I really need to spend over the cost of the Vanquish to get a great detector? I’ve had and have higher cost detectors but I want your opinion . Chuck
  10. Well it’s official. The Garrett GTI 2500, the flagship of the Garrett metal detector lineup, was over 20 years old in 2019. The GTI 2500 was introduced in 1999. Twenty years is an awfully long time in technology land, and I’d say it’s well past time for Garrett to do something about that. What would you like to see from Garrett in 2020? Garrett GTI 2500 Data & Specifications
  11. I love analogies. Maybe this one will help some people. Low recovery speeds magnify signals and fast recovery speeds truncate signals. Digital machines usually chop signals into discrete portions. A target is “grabbed” and then it is “released”. A new target cannot be “grabbed” until the last one is “released”. Imagine a conveyor belt going by with a line of wooden blocks. The blocks have anywhere from 9 to 16 sides. You are standing there blindfolded as the blocks go by. You can pick up a block and feel it for as long as you want to try and decide how many sides it has. The longer you roll it around in your hands, the better. Your chance of deciding if it is a thirteen sided block or a fourteen sided block is better if you have more time. However, you are being graded by how many blocks you identify correctly, and if you hold one too long some pass by before you can pick them up. The conveyor is passing 8 blocks per minute past you. If you have a recovery speed of 1 you hold each block one minute and you get a great “signal” on that block. But seven other blocks go by as you are taking your time identifying the one block. You increase your recovery time to three and now get 3 out of 8 blocks but have less time to hold each block. Less signal information. Still, you get them all right. Now you increase recovery time to 5 and are only missing three blocks. Your slower buddies are having a hard time keeping up now and making mistakes, misidentifying blocks, but you are doing great. You notice that people standing back are having to reach farther to grab a block and put it back. They are “going deeper” but it is costing them time. You step closer to the conveyor belt so you don’t have to reach as far, and are now a little faster by not reaching as far. You lose a little “depth” but gain some speed. You go to recovery speed seven and your arms are a blur. Your buddies all give up and stand back in awe as you pick up and put down blocks at lightning speed, and are still calling them right but you can tell you are at your limit. You finally go to 8 and still get almost all right it every now and then you have to put a block back down before you can tell what it was. You don’t have enough time, enough signal to work with. You also get to change the conveyor speed. You can swing your coil slower, and now you have more time to look at each target. That means you can lower the recovery speed and still keep up with the targets. Great for the slower workers (detectors) who have a hard time keeping up. That is a decent analogy for recovery speed and what it does for the ability of a detector to clearly examine a target versus how many targets it can process and how far it can reach. Slow detectors, slow conveyor workers, don’t have a chance. Only the fastest workers, the fastest machines, can pick up and process all the targets correctly in a short period of time. They are a rare breed. One of the biggest advantages you possess in Equinox is the lightning fast recovery speed. I see far too many people throwing that advantage away thinking a lower recovery speed gets “more depth”. No point in getting an Equinox then, just stick with the slower machine you already have. Give Equinox a real good go at the default higher recovery speeds before deciding to toss away what is perhaps the most important advantage the machine has - lightning fast recovery time coupled with accurate target id and minimal depth loss at those high speeds. That is the Equinox difference. Don’t waste it. Recovery Speed, Recovery Delay, And Reactivity
  12. The latest issue of the ICMJ is out, and I have an article in it titled Selectable Frequency vs Multi Frequency Detectors. Those of you with a digital subscription can read it online. The ICMJ has a policy against mentioning brand names in articles so I wanted to post this as a supplement to the article. Most metal detectors process a single frequency. Low frequencies, that is single digit frequencies under 10 kHz, react well to high conductive targets, like coins, or large items, even if those items are of low conductivity. If you look at this typical metal detector target scale below you will note that non-ferrous items read higher not just based on conductivity but size also. Low frequency detectors also do not "light up" the ground or hot rocks as much as detectors operating at higher frequencies. Many do not even offer ground balance controls because a factory preset level works well enough for some uses. Low frequency machines under 10 khz therefore tend to be aimed at the coin detecting market. There are too many models to list but most people have heard of the 6.5 khz Garrett Ace 250 as a perfect example. High frequencies 30 khz and over have extreme sensitivity to low conductive and small items, but also struggle more with ground penetration and hot rocks. Their extreme sensitivity to tiny trash items like aluminum bits do not make them very practical for any detecting except gold prospecting. Machines 30 khz and higher tend to be dedicated prospecting machines. Examples would be the 48 khz White's GMT, 71 kHz Fisher Gold Bug 2, 56 kHz Makro Gold Racer, and 45 khz Minelab Gold Monster 1000. In 2002 White's introduced the White's MXT at 14 kHz, and it is a perfect example of how detectors running in the "teens" make excellent "do-it-all" detectors. Since then everyone and their brother has jumped on that bandwagon, and there are too many machines running in the 10 kHz - 20 khz region to mention. Prospectors in particular would recognize the 19 khz Fisher Gold Bug Pro, but few know it is also sold in slightly different versions as the Teknetics G2, Fisher F19, and Teknetics G2+, all 19 kHz detectors sold to the general coin and relic market. Garrett has the 15 kHz AT Pro and 18 khz AT Gold to name a couple more popular metal detectors. Here is some information for those of you who are more technically minded. George Payne was one of the engineers who patented many of the basic concepts used in VLF detectors to this day. Here is an excerpt from his article at http://jb-ms.com/Baron/payne.htm (2002): "The r component acts differently. It is maximum at one particular frequency and decreases if you go up or down in frequency. We call the special frequency at which the r signal is maximum, the target’s “-3db” frequency. It also turns out that at the -3db frequency the x signal is one-half of its maximum value. This special frequency is unique to each target and is different for different target. The higher the conductivity of the target the higher will be the targets -3db frequency. Conversely, the lower the conductivity the lower the -3db frequency. The -3db frequency of the high conductivity target will also make the r signal peak at a high frequency, normally well above the operating frequency of the VLF detector. This will make the high conductivity target have lower sensitivity on the VLF detector because the r signal amplitude drops if we are significantly below the -3db frequency. Simply put, maximum sensitivity on a VLF detector would be if we position the operating frequency directly at the target’s -3db frequency. For example, a dime and penny have a -3db frequency of about 2.7KHz. This is where their r signal peaks and would be the best frequency for picking them up using a VLF detector. However, a silver dollar has a -3db frequency of 800Hz. Nickels, on the other hand, have a -3db frequency, where its r peaks, at about 17KHz. Targets like thin rings and fine gold are higher still. Clearly there is no one frequency that is best for all these targets. The best you can do is have an operating frequency that is a compromise." Well, if low frequencies are good for coins and high frequencies good for gold, why not make machines that can do both? Or both at once? Instead of picking a compromise frequency? Selectable frequency refers to machines that can select from one of several possible frequencies, but process the signal from only one frequency at a time. The key is not what a detector transmits so much as what it processes. These may also be referred to as switchable frequency detectors. Multiple or multi frequency detectors process the signal from two or more frequencies at once. In theory this multifrequency analysis can be done simultaneously or sequentially at a very high speed. The end resultant is the same - the results from two or more frequencies are compared to derive information that cannot be had by analyzing a single frequency alone. Multiple frequency detectors usually have a fundamental frequency, and then other "harmonic" or secondary frequencies they also use, but the power (amplitude) fades with distance from the primary frequency. From page 9 of Minelab's Metal Detecting Terminology: You can find more information on harmonic frequencies at http://www.ni.com/white-paper/3359/en/ and here also. Coils normally must be wound specifically to make use of any given frequency or set of harmonic frequencies. A coil will usually work best at the given fundamental frequency making it difficult to get the best possible performance at all frequencies using one coil. The Minelab X-Terra series specifically requires a coil change to achieve a frequency change for this very reason. People who own them know 3 kHz coils weigh more than 18.75 kHz coils. Why? Because heavier windings are used at 3 khz for optimum performance at that frequency. Here is what is probably an incomplete list of selectable frequency detectors and year of release: 1989 Minelab Eureka Ace Dual 8 kHz 19.5 kHz 1993 Minelab XT 17000 6.4 kHz 32 kHz 1994 Compass X-200 6 kHz 14 khz 1997 Minelab XT 18000 6.4 kHz 20 kHz 60 kHz 1999 Minelab Golden Hawk 6.4 kHz 20 kHz 60 kHz 2002 Minelab Eureka Gold 6.4 kHz 20 kHz 60 kHz 2005 Minelab X-TERRA 50 7.5 kHz 18.75 kHz 2006 Minelab X-TERRA 70 3 kHz 7.5 kHz 18.75 kHz 2009 Minelab X-TERRA 305 7.5 kHz 18.75 kHz 2009 Minelab X-TERRA 505 3 kHz 7.5 kHz 18.75 kHz 2009 Minelab X-TERRA 705 3 kHz 7.5 kHz 18.75 kHz 2009 XP DEUS 4 kHz 8 kHz 12 kHz 18 kHz 2016 Rutus Alter 71 Variable 4 - 18 kHz 2017 XP DEUS V5 Additional 14 kHz 30 khz 55 khz 80 khz options 2017 Nokta Impact 5 kHz 14 kHz 20 kHz 2017 Makro Multi Kruzer 5 kHz 14 kHz 19 kHz 2018 Nokta Anfibio 5 kHz 14 kHz 20 kHz Multiple frequency or multi frequency machines have become very confusing, as a lot of marketing material has focused on the number of frequencies transmitted. What really matters is what frequencies a detector receives, and how the information is compared and processed for results. Some commentary here. Many people look at the marketing material and assume that a machine processing multiple frequencies is somehow working across the board to deliver the best possible results at all frequencies. However, the two issues outlined above do apply. The machines are employing harmonic frequencies, and so cannot compete with a machine optimized at a single frequency as opposed to one of the distant harmonics running at less amplitude. Second, making one coil run perfectly at all frequencies is extremely difficult, again giving the dedicated machine an edge. I highly recommend people not go down the technical rabbit hole but instead focus on what the machines do, on how they act. Two things are very apparent. First, the big market for a long time was coin detectors, and the goal always was to identify coins as deep as possible while ignoring trash as well as possible. Processing two or more frequencies simultaneously gives the detector engineer more information to work with. All the focus was on developing great coin detectors and guess what, the multi frequency machines for all intents and purposes act just like very good lower frequency coin detecting machines. Good ground rejection, and great discrimination on coins for as deep as it can be achieved. The multi frequency machines don't really go deeper than single frequency coin detectors, they just do a better job delivering clean discrimination results to depth. Here is a list of introductory models of multi frequency detectors and year of introduction. I am not listing all the derivative models to reduce clutter. I will post that later. 1991 Fisher CZ-6 5 & 15 kHz 1991 Minelab Sovereign BBS 1999 Minelab Explorer S/XS FBS 2001 White's DFX 3 kHz & 15 kHz (Simulates single frequency by ignoring half the dual frequency signal) 2012 Minelab CTX 3030 FBS2 2020 Minelab Vanquish Multi-IQ Second, single frequency detectors have a ground balance problem. They can ground balance to mineralized soil, OR they can ground balance to salt water. Multi frequency machines can reduce signals from both mineralized beaches and salt water simultaneously, making them ideal for saltwater use. 1993 Minelab Excalibur BBS (Sovereign in waterproof housing) 1995 Fisher CZ-20 5 & 15 kHz (CZ-6 in waterproof housing) 2001 White's Beach Hunter ID 3 & 15 kHz (DFX in waterproof housing) There is a third class of machine that can run either as selectable frequency OR multi frequency detectors. Quite rare at this time. 2009 White's Spectra Vision 2.5 Khz or 7.5 kHz or 22.5 kHz or all three at once 2018 Minelab Equinox 5 kHz or 10 kHz or 15 kHz or 20 kHz or 40 kHz plus multi frequency options 2020 Garrett Ace Apex 5 kHz or 10 kHz or 15 kHz or 20 kHz plus multi frequency options In my opinion multi frequency has delivered well on its promise. The Minelab BBS and FBS machines are renowned for their ability to discriminate trash and detect coins due to their sophisticated processing. Again, focus on what they do. Not even Minelab in their marketing tells anyone these are prospecting detectors. Second, the Fisher CZ-20/21 and various Minelab Excalibur models are without a doubt the most popular and successful non-PI saltwater beach detectors made. I have a White's DFX and I think it is a fantastic jewelry machine in particular. A good coin machine but lacks a bit of punch. The Vision/V3i upped the ante but while amazing on paper suffers from interface overload. The Minelab units are simple by comparison and a lesson on how people in general just want the detector to get the job done. Feature overload is not a plus. However, I think White's has the right idea. The ability to run either separate frequencies or multiple frequencies at once is very compelling. I just think nobody has really done it right yet in a properly configured package. The V3i has the ingredients, but needs to be stuffed in something like an MX Sport with a simplified interface and improved ground balance system. (2018 note - Minelab Equinox released). It really never did beat the White's MXT in some ways and many people when "upgrading" to the V3i end up going back to the MXT. Selectable frequency has yet to really deliver on its promise in my opinion. So far it has been difficult to produce a selectable frequency machine that truly performs at all frequencies on par with a dedicated single frequency machine. The Minelab Eureka Gold at 60 kHz just never gets mentioned in the same breath as the White's Goldmasters/GMT or Fisher Gold Bug 2. Also, most selectable frequency machines in the past have been very feature limited prospecting machines, restricting their overall market appeal. I personally think we have seen enough variations of single frequency detectors. I do not believe much can be done to exceed the performance of the dedicated single frequency VLF type machines we currently have. What can obviously be done is a better job of packaging machines that deliver true punch at different frequencies, or multi frequency machines that bring across the board performance closer to what is expected of PI detectors. I do think we are seeing this happen now. The new Nokta Impact and the new DEUS V4 update are expanding the available options in selectable frequency in more usable packages. The Minelab GPZ and other hybrid platforms blur the line between what is traditionally considered PI and VLF and simply need the addition of discrimination to go to the next level. There is still a lot of potential to deliver machines that might reduce the number of machines many of us feel compelled to own by delivering more across the board performance in a single machine that would now take several detectors. Exciting days ahead. For those who want to try and get their head around selectable frequency and multi frequency technology, Minelab and White's have a gold mine of information in a few of their references. Dig into the following for some great explanations and diagrams. Minelab - Metal Detector Basics and Theory Minelab - Understanding Your X-Terra White's - Spectra V3i Owners Guide White's - V3i Advanced Users Guide Better yet are the last three parts of the DFX instructional video by White's featuring engineer Mark Rowan explaining frequency and multi frequency methods:
  13. Hey guys n girls I have a doozie of a question for anyone that may be in the know. I'm not sure how to ask this without being negative towards a great detector Minelabs GPZ7000 approx $9000 Australian dollars. I was watching some YouTube videos on the Ajax Segma 3d metal detector. It has an 8m depth. Finds all types of metals, water even under ground caves. The cost is A lot less than a GPZ7000 My main question is why have we not seen or heard more about this in Australia. I mean if not for general gold detecting, but for bigger companies using it to find the depth of the gold they need to mine. Check out the detector by Ajax and I think the other one is a company called Ger from Germany.
  14. so all you guys know your Detector? Or so you thought maybe or maybe so you thought?  So lots of you may be asking or have been asking or are curious about which Detector is better and probably assuming the 800 is way better and stronger than the 600. Or which is better for the beginner? The Minelab Equinox 600 or 800? What Detector is more powerful? Therefore producing more finds and at better quality? Or are they in a nutshell the exact same Detector besides A extra mode ( Gold ), and 20 and 40 khz are available to be single frequencies on the Equinox 800 and not the 600. Does The Equinox 600 have 20 and 40 khz in multi frequency? And the 800 has more adjustable tone pitches in more tone brackets and recovery speed is more adjustable and iron bias as well. But are as I said in a nutshell are the same exact animal. Truly deep, capable of all types of metal detecting adventures, fully submersible and the actually find amazing finds. Whatever you buy make sure it's a Minelab Equinox. They produce. Just don't go about it like I did and dying to set up most advanced settings and trying to copy someone's program. Let that metal detector talk to you and you'll create a bond with it and only tweak it when you feel the need to be able to comprehend it better. It's preset modes are incredible and this detector is truly worth every penny.... Thanks for listening guys
  15. 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.
  16. Just curious, how many prospectors are still swinging around a Minelab SD series, GP or even GPX4000?? These models hardly get a mention these days. For those that are swinging these older models, here's a few additional questions do get a bit of chatter happening....maybe Have you tried any of the new flat/spiral wound coils? Have you tried modern boosters, or aftermarket battery options? On a personal note, I still have a SD2100e and a GP3500 but they don't get any serious use. The 2100 is very sentimental model to me as it was the detector I found my first nugget with. The GP3500 was my baby, where Minelab added everything I wished for. It still has the best audio in any prospecting detector I've used to date (admittedly she's a bit on the quiet side).
  17. any thoughts on the use of a geiger counter instead of a metal detector for prospecting ....U , TH , TE , IN , RB , RE , PT
  18. Hi All I've been hearing rumours of a new gold machine in the works ? Is there any truth in this and if so what are some of the rumours or truths about it. Cheers
  19. I’ll post link here. Folks can comment if they wish. Saves me time by not posting in detail on all forums. I like this forum very much. Hope I am not breaking rules here or am not upsetting anyone. http://www.dankowskidetectors.com/discussions/read.php?2,173272
  20. Here is a good Sunday read for you. Reg wrote what is still the best introductory text on PI detectors. Recently he added extra chapters at the Findmall forum. Even if you read the original before it is worth reading again. Understanding The PI Metal Detector by Reg Sniff http://chemelec.com/Projects/Metal-1a/Understanding-the-PI-Detector.htm Deepest PI Detector by Reg Sniff Part One Link deleted since Findmall update broke old links Deepest PI Detector by Reg Sniff Part Two Link deleted since Findmall update broke old links
  21. Hello Guys, I'm new on this forum and like Alexandre Tartar, I live in north of France. I was a young prospector in the 90's and asked my father (electronic engineer with good knowledge in magnetic field theory) to build a PI to hunt the beaches. So we have made, in a few months, an home-made PI metal detector 25 years ago, based on the technology of the old White's Surfmaster PI (mono coil). I remember the use of FETs (Field Effects Transistors to make 200 volts pulses). It worked, but unfortunately, my father was afraid by a so powerful magnetic fields and has continued his research on VLF detectors, until today ! After this short presentation, here's my question : Is the Impulse AQ a bipolar detector ? Le Jag has explained us on the french forum "detecteur.net" this technology developped by Alexandre : Positive and Negative pulse are alternatively sent. The positive one light the gold ring but magnetize the soil. The negative one demagnetize the soil. What about it ?
  22. http://www.dankowskidetectors.com/discussions/read.php?2,172859
  23. From the Codan news release at http://www.codan.com.au/Portals/0/investorpubs/22 AXS Announcement - Minelab awarded $6.7m contract.pdf (copy below): "Cooperating with NIITEK Inc., the HDD will combine Minelab’s new Multiple Frequency Continuous Wave metal detection technology and NIITEK’s advanced ground penetrating radar." 31 August 2016 MINELAB AWARDED CONTRACT TO DEVELOP NEW HANDHELD DEVICE DETECTOR FOR THE AUSTRALIAN DEFENCE FORCE Minelab Electronics, a wholly owned subsidiary of Codan Limited, has been awarded a $6.7m contract by the Department of Defence to develop a new Handheld Device Detector (HDD). The funding received under this contract is to further develop a dual sensor metal detector which incorporates ground penetrating radar. It will partially offset the development costs of the product, and the project is expected to be completed by 2018. The development of the HDD builds on Minelab's success in technology development and product innovation for use in military programmes. Codan is particularly pleased to be of service to the ADF and to provide an enhanced capability that currently does not exist. Once the HDD enters into service with the ADF, we are confident that other militaries will seek the same level of capability, broadening our market for countermine products. The contract supports Codan's stated strategy of growing its profitability by improving and broadening our product offerings while ensuring our value propositions remain relevant and leading-edge. Previous to this award, in March 2014, Minelab was selected by the Department of Defence's Rapid Prototype Development and Evaluation (RPDE) programme to receive $1.0m in funding to further integrate metal detection and ground penetration radar technologies into a lightweight and compact mechanical platform. In December 2014, RPDE provided an additional $1.3m in funding, and Minelab subsequently produced an advanced prototype of the HDD. Cooperating with NIITEK Inc., the HDD will combine Minelab's new Multiple Frequency Continuous Wave metal detection technology and NIITEK's advanced ground penetrating radar. The HDD was designed taking into account the comprehensive requirements of the ADF, supplemented with feedback from Army User Groups. It will include advanced detection technologies as well as new standards of compactness and ergonomics. On behalf of the Board Michael Barton Company Secretary MORE INFORMATION ON THE NIITEK/MINELAB GROUNDSHARK Minelab Mineshark
  24. Show simple targets you swore were gold. These were 12" inches plus in depth (all lead)....... Found with a borrowed GPX 4500
  25. The GB knob on my Tejon is super loose now after the tons of hours I put on it and I get a little waver in the threshold. Trying to find who sells damping grease in really small quantities as the stuff is horribly expensive. Mcmaster has some at $111 + shipping, Amazon has some in the $30 range and all more expensive than the potentiometer itself. I could replace it but rather not start soldering in parts if I don't have to.
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