GB_Amateur

Wecome, Matt! IMO the X-Terra 705 is a better choice than the Vanquish for one over-riding reason -- it has adjustable ground balance and the Vanquish models don't. (I know that the hard way, well maybe better said "the soft way" since I got it wrong in a thread/discussion regarding the Vanquish here on this site a few weeks back.) You said the Equinox 800 was out of your price range, so that eliminated it. I'm definitely one who sticks to my budget. A lot of people argue that you spend more and that you should start with the biggest and best. Not I. "You get what you pay for" sounds good, and it's right except when it's wrong. Even more pertinent, though, is that of the three components of detecting, the detector comes in third after 1) site/location and 2) skill/capability of the person swinging the detector. (Note that research, very important, is a combination of 1 and 2.) I have an X-Terra 705 but never used it for gold detecting, where I've read from more than one reliable source that it is better at that than for other forms of detecting. (It has a prospecting side and a coins/jewelry/relic side and I only used the second.) I bought several coils and my favorite was the 6" round DD @18.75 kHz, and I was coin hunting. I suspect the 5"x9" DD @18.75 kHz would have worked as well or better for me but I only bought that late in the game to 'complete' my package. So you are set. Bottom line -- you have a good detector for the job. Don't doubt it. Learn to use it, find (with research) a good place to detect and go have fun! P.S. You said you are in Colorado. I heard they have a state-wide gold prospecting club that researches available -- meaning unclaimed -- properties and shares their findings with members. I'm pretty sure Jeff McClendon (member here) knows of them and maybe belongs. He can give you more info. I would PM him; he won't bite. 😁

You're welcome but it's mutually beneficial. From a scientific standpoint, these thought experiments can only take us so far. They tend to be (as this one is) purely qualitative. Theoretically you need to get into the (quantitative) weighting of the different effects. Best is to experiment because mother nature never forgets to include a component,... ever.

I couldn't resist -- I had to click on the ad and find out what was going on. I only got as far as investigating the product on the left, and am still not sure how it works. But it was in the Salvador Dali section of the website so that might be a hint....

True, but your advice and backup gave him the confidence he needed. If you hadn't volunteered to help he probably would have ended up empty handed and having to shell out the $195+. Great effort (and story), Joe!

Here's a piece of an ad that showed up on my browser page while reading the forum. I sometimes miss figuring things out but this one (on the surface) seems too far out there to have me fooled, but I never really know. The one on the left is particularly bizarre. Maybe just kids toys that don't actually work but make them think they are detecting? (I could have clicked the ad and gone to the site but I'm always concerned that this will lead to me being targeted by more of their ads.)

Steve, thanks for your thoughtful and detailed response. I think this might be the case where we agree to disagree, and that's certainly fine with me. I don't know that I can come up with a better way to illustrate this torsion, but I do think it occurs even with the description of the way you swing (although your method/technique should make it much less stressful than the way many others swing). My original analogy (which I shelved) was the torsion that can occur with a golf shaft when the ball is struck off the club face's sweetspot (e.g. towards the toe of the club) but I think that might introduce complications or physical processes that aren't really applicable to swinging a metal detector. It also is likely less valuable of an analogy to someone who isn't familiar with the game of golf. I certainly agree that the torque on your wrist from the toe-heavy imbalance is an issue (a different issue, but certainly probably a much more severe one). I can tell that you think of these things way more than most people and use those ideas and experiences in your designs. I do wonder, though, about your conclusion that you haven't noticed any torsion means there isn't a (imperceptible) torsion present. I remember talking to my doctor about athletic injuries (which metal detecting certainly can cause, as you note) and that small, seemingly insignificant (unnoticed?) forces which are repeated hundreds of times can lead to problems. In my case (and I'm sure I don't think about it and thus am less aware than you), I've gone out swinging away not noticing any forces the elbow of my detecting arm and then get home (or wake up the next morning) with pain there. That's an extreme example compared to the torsional effect I hypothesize. I'm certainly not 100% convinced myself that what I've tried to illustrate is real, let alone a problem. If it were important enough to me I'd think up and then attempt experiments to see if it's real. However, I'm really not that dedicated to this topic. In the end I respect your decision not to pursue fabricating S-shafts and look forward to your future innovations.

If you're going to be going out-of-sight of your vehicle: Whistle, small mirror, and some way to start a fire (matches in a waterproof holder, fire stick,...). A space blanket (here is an example but the one I carry is smaller and lighter) is a good idea, too. Take something red or orange (e.g. hat). A portable filter (an example) is lightweight and another potential lifesaver. BTW, the mirror is for signaling a search aircraft. If/when necessary, hold your hand at arms length with the index and middle finger pointing up in a -V- (kinda like a slingshot yolk). Get the aircraft in your site -- the two fingers. Hold the mirror in your other hand next to your eye and direct the sunlight between those two fingers on your extended hand. The point is that there are a lot of lightweight emergency items that take up very little room and that are affordable. Even if you never need them it's good peace-of-mind (for you and your loved ones).

First off, I commend you for your ethics -- not wanting to market a product as a solution to a problem if it's not a solution at all. Secondly, apparently I'm the one who prompted you to answer. I didn't ask a direct question but hoped you would see this and respond, and you did so thanks for that. My understanding of the argument for an S-shaft is shown in an over-simplified and exaggerated fashion in this sketch: (I would have made this on a drafting table but it's not 1980 anymore. But as you can see I did find a vintage bottle of White Out!) The purple squiggle is a hand gripping the detector backbone structure. The arm cuff is shown rotated 90 degrees (I'm even worse at 3d drawing than thus made this 2d attempt). It's a bit easier to think of the shaft as massless although even with mass I think the point I'm trying to illustrate still holds. (See comment at end of this post.) Imagine moving these stick-detectors into and out of the page as a simulated swing. Consider the forces that need be applied (by your arm+hand, etc.) The first drawing is an unrealistic view of a perfect(?) shaft and grip. The second one is the more realistic straight shaft with pistol grip. Third is S-shaft with pistol grip and fourth is standard S-shaft. Pretty sure in the second case there is a torsion (twisting force) that occurs at the two ends of the swing which requires an offsetting torsion be applied by the human hand. It's that repeated torsion that is alleviated but the S-shafts (lower two models in drawing) which leads to less stress on wrists and elbows. If the shaft (including pistol grip section) has no mass then the first, third, and fourth models are conceptually identical. (When you account for the mass of the shaft there will be some torsion of the upper shaft part in the lower two [S-shaft] models, but it is less than the torsion caused by the shafts' masses alone in the second -- straight shaft model.) P.S. (to steveg): I do like to support members here for the products they fabricate and sell. But I don't tend to do that when the product replaces something I'm already satisfied with. I've already made my own S-shaft by modifying the X-Terra S-shaft so don't count me on your list of potential buyers, although I wouldn't completely rule that out. Your shafts are lighter and that alone is enough to lead to my consideration.

Maybe not but I bet steveg would know. It certainly injects sticker shock compared to its competitors. Is a true carbon fiber S-shaft difficult/expensive? If so why not 3 sections with only the middle (small) S-section being aluminum and the rest carbon fiber? Another way to look at this is that this company has a product and they put a price on it. No one is being forced to buy it. If someone really prefers S-shafts (I do) and on top of that would like a more compact version for backpacking (I guess this is such) then $219 or $180 may be worth it. They might be testing the waters for other products. They can always drop the price later if this doesn't work. Meanwhile I'm fine with my X-Terra S-shaft kluge.

Great idea. 👍👍 ML can still limit the Eqx 600 users to fewer choices but at least use the same language/nomenclature/numerology so that when we discuss on forums we don't get confused. (I've gotten confused on many occasions.) This applies to all the settings (Recovery Speed, etc.) that are common to both detectors. Communication is big in this hobby and it sometimes gets lost in the weeds or forgotten when seemingly more important issues dominate the attention.

Did they say if it saved weight compared to the stock shaft? I like innovation and this qualifies. But I also like to keep a few $ in my pocket....

While this topic is hot and on our minds, I'm going to make a request. Could someone with detailed technical & engineering knowledge write up a report explaining Iron Bias at an intermediate-to-advanced user but still layman's level? The kind of description I'm requesting is one similar to what was done in Randy Horton's excellent monograph Understanding Your X-TERRA which contains an interview with Minelab scientist&engineer Dr. Laurence Stamatescu (starting on page 79) where he melds the right combination of technical info and easy to follow wording. Maybe there has already been such a writeup that I'm not aware of, but although I appreciate what has been posted here on the forum on this subject I'm still confused/confounded as to what is going on and how to best utilize it. I don't seem to be alone on that. One of my many gaps in understanding is whether or not all detectors have an effective (but fixed) iron bias setting, with only a few giving the user the option of dialing it in for best performance. Related: when iron bias on the MInelab Equinox is set to zero (in either F2 or FE), is there still some kind of iron bias occurring? Knowing how a detector works transfers over to optimizing it's use and I'd like to do more of that instead of just locking iron bias on one value for all applications and conditions (or blindly accepting factory defaults) -- what I (and apparently most users) do now based upon ignorance. (Well, I'm ignorant on this subject -- not trying to associate that with any of you. 😏)

Excellent story. But on the "change what you think" theme, aren't the carbonaceous chondrites a) rare, and b) not metal detectable? (not sure about the latter since a large piece of graphite will set off a detector; however I don't know what form of carbon are in these) Amazing how much can be deduced from the few pieces of evidence we get. Most of us (yep, not nearly all nor enough) get a very different view of these natural phenomena than our caveman ancestors did. Too bad Dogodog wasn't aware of this earlier, although Lunk is an adventurer and (in case you didn't know it ) the area where this came down is known for the occasional piece of yellow metal. Hmmm.

When I first got my Equinox 800 I tried out the ML-80 headphones -- sound seemed OK but they weren't as comfortable as my usual headphones (more on those in a minute) and they definitely didn't block out the surrounding noise as well. I actually have a summer setup (earbuds -- wired kind) to keep my ears cool, and winter, to keep them warm! But on top of that, I own five sets of over-ear headphones (on-ear are ridiculously uncomfortable) and have tried a couple others. One set in particular stands out for me -- Sunray Pro Gold. They are best of any I tried at blocking out ambient noise and their sound quality (for my ears) stands out. The WM08 module in combination with the other Eqx 800 options offer everyone 100% choice of headphones. (Wish they had a 1/4" socket, but I get by with an adapter.) I'll quote the cliche' "optionality is always preferred!" I hope that doesn't change. A few months (many hunts) after shelving the ML-80's I tried them again. This time, with something to compare to, the sound quality left me disappointed. That was it -- I haven't used them since. They are backups to my two WM08's (bought a 'slightly used' WM08 on Ebay for about 1/3 the price of a new Minelab unit...) Regarding the latency, I'm careful not to put too much emphasis on my experience. It does seem that I notice a slight lag when swinging quickly (e.g. investigating an already found target) even with the WM08's. I haven't done any careful studies on that although some back-of-the-envelope number fiddling indicates even the very low latency of the WM08 should be noticeable with a quick swing. ('Quick' is equivalent to a putter head speed when attempting a 10 foot = 3 m putt at golf, so not lightning fast by any means.) However, that isn't the reason I use them; it's just a bit of icing on the cake. If I had to pay the ridiculous list price for the WM08's I wouldn't bother. (I assume we're supposed to be frank with our replies. Does anyone think the WM08 list price is reasonable??) I have a similarly very low latency Garrett Z-Lynk T/R pair that works fine (but of course there I need to plug in the transmit module so an extra link in the chain). I know I'm in the minority but the WM08's are a huge plus for me.

I've mostly been hunting parks and schools for old coins with the Minelab Equinox 800. My experience is primarily in those sites for those targets. I've logged 700-750 hours under those conditions. I've upgraded the software each time a new version has become available. I've experimented with the Iron Bias settings. My method has been to compare the detector's response at the minimum (0) and maximum (9) values. I've done this with both FE and F2 for the same (unknown) targets before digging. I can't say that I discovered a lot other than that rusted crown caps tend to show a big difference between F2=0 and F2=9. For me, crown caps aren't much of a problem (not a frequent trash target -- maybe averaging digging a couple per hour) in my sites when they show up in the USA 5 cent ('nickel') zone of 12-13. I've found that I can use Field 2 (50 tones) to identify them reasonably well (by differences in TID's between Field 2 and both Park 1 and Field 1) without having to tune the iron bias settings. (I tend not to dig TID's between 14 and 18 due to the plethora of aluminum trash, particularly complete and partial pulltabs. So if crown caps were to ID there I have been ignoring them -- i.e. not digging.) I've done some experimenting with other targets, while still buried and thus unknown. I have not found either FE or F2 (again, comparing detector response at their extreme setting values) to be a reliable indicator of iron/steel nails -- and nails can be a much bigger problem for me (due to being plentiful in many old sites) than crown caps. For the most part I've stopped changing iron bias and keep it set at F2=0. I have noticed a tendency for deep (7"-8" in my moderately mineralized soil) to give iron tone hints, even at F2=0, but more so with non-zero values of F2. The effect is subtle but noticeable. That has driven my decision to keep my iron bias setting at F2=0.

I recall Garrett's advertising literature (don't know if it's still this way) making a distinction that the AT/Gold worked in fresh-water but not salt-water, indicating if you wanted to hunt in salt-water to get the AT/Pro. Hmmm. Well, I'm not from Florida so maybe I'm not supposed to question an 'expert', but when my in-laws lived there I'm pretty sure the term 'snow birds' referred to people who lived in the north during the summer and 'flew' down for the winter. We're more like snow foxes -- we hang around and do the best we can with the conditions. And to get even more off-topic, if you want to see a good picture of a snow fox (more commonly called 'arctic fox') there is a Lincoln SUV commercial that's been showing lately that starts with a view of one of these animals curled up on top of the snow all fluffed up, with wind whipping around, low daylight conditions, and sound effects to match. Brrrrr. Amazing animals!

Minelab Equinox 800: 97% (most of that was with 11" coil) Fisher F75: 2% (2/3 of time with 13" Detech Ultimate; rest with 5"x10" Fisher concentric) Tesoro Vaquero: 1% (w/5"x10" Tesoro Lobo Supertrack stock coil) Fisher Gold Bug Pro and Minelab X-Terra 705: 0% (aka 'closet queens' 😁) PI's: 0% (used for gold prospecting which I was unable to do in 2020 due to travel restrictions from Covid-19). The Equinox gets most of my time mainly because it keeps better TID as depth increases compared to the F75. At the end of the year I bought a ~5"x10" DD (Mars Sniper) for the F75 and already have used it once this year. (Now we find out that Coiltek is releasing a similar sized coil for the Eqx....) The Vaquero is a throwback to simpler times and I use it mainly to try and open my mind (more specifically train my ear) to different sound qualities which I hopefully can then apply to my other detectors. Oh, and the 2.5 hour (only) hunt with the Vaquero found an Indian Head penny. 👍 So every one of my five IB/VLF's has done that now.

It's been mentioned earlier in this thread that this coil is meant primarily for water immersion detecting. But the 15" is listed at 836 g (no cover attached?) compared to the ML 12"x15" at 674 g (my measurement that includes the cover). I have a Coiltek 15" for my X-Terra (864 g w/cover) and a NEL Attack for my Gold Bug Pro (819 g w/cover) and have to agree that those really make my detectors toe heavy to the point is distraction. BTW, the new NOX (hate that name!) 15" from Coiltek looks like the identical housing (except for color) as my X-Terra coil.

Are those mine dumps or tailings piles, or both? (Maybe vets here can tell from the photos, but not I.) Did you check any of those piles with your detectors, or is the gold known to be too small to give a signal on a detector, especially in that high mineralization you mention? Thanks for the pics -- but it does make me long for this vaccine distribution to accelerate (although lots of more important reasons for that exist, too).

Welcome, RR. (BTW, I there is another poster -- from Great Britain -- with a similar username, think it's 'rivers rat'. Nothing wrong with that as there are lots of cases here where people have very similar usernames. Just warning there may be a bit of confusion until people realize there are two of you. 😁) Regarding your choice of detectors, IMO you are doing things right by studying the information first, and this site is probably the best one out there, at least for gold detectors but maybe for all modern detectors. In the old (pre-internet) days there were dealers all around you could visit but only a few of those remain and I don't know if there are any close to you. Even back then you often had to shop around since a lot of dealers only had one or two brands and of course they would steer you towards those. Two active members here who are multiline dealers are Gerry McMullen and Rob Allison (I've linked their store websites.) A phonecall or two isn't a bad idea, IMO.

I know you've said this before but I'm wondering what this is based upon. Is it theoretical or found with measurements/experience or ??. My limited measurements have indicated depth for USA pennies and nickels goes as the geometric mean (square root of the product of the two axes) so dependent upon both. Other factors, espeically ground mineralization, can be large contributors as you and most(?) readers know. I've not done comparisons in air.

That seems in the ballpark of other similarly sized coils although maybe on the higher end of the distribution since it was weighed without cover, I assume. Here are some comparisons (my measurments except as noted; all are DD's except as noted). Note that some dimensions are measurements I've made while others are what is advertised by manufacturer, so this might account for some of the variation: Mars Sniper 6"x10" open (for Fisher F75), no coil cover (they don't make one for it) -- 392 g Fisher 5"x10" closed for Fisher Gold Bug, w/coil cover -- 460 g Nel Sharpshooter 5.5"x9.5" open (for Fisher Gold Bug) w/coil cover (?) measured by Phrunt -- 424 g Minelab 5.5" x 9.5" 18.75 kHz closed for X-Terra 705 (no coil cover; not waterproof) -- 386 g Tesoro 5"x10" 4-pin open (stock on Lobo Supertrack) w/coil cover (waterproof??) -- 434 g Miner John 5"x9" folded mono closed (for White's TDI) w/coil cover (waterproof??) -- 384 g

I'm going to stop posting on this thread, I swear. But when I quit is another question. Several years ago I attended two lectures by a mathematician/statistician/probabalist name Persi Diaconis. The two one hour lectures delivered 24 hours apart were seemingly contradictory (paraphrased): "How people use scientific arguments to fool themselves into thinking something is false" and "How people use scientific arguments to fool themselves into thinking they are true." I've since learned both fall into a broad category called 'cognitive bias'. It's basically how your mind can trick you into being convinced with suspect or fallacious data. I wish I had a transcript of those lectures. He showed 10 bullet points in each lecture that illustrated the weaknesses that many people suffer, including people who you might expect to know better (e.g. scientists). The one I remember is that when someone else makes a claim it's a lot easier to dismiss it than when you make a similar claim yourself. "Oh, but I experienced this myself so it must be true,...." There are plenty of people who will use the above paragraph as evidence that science is worthless. Scientists are vulnerable to fooling themselves so that throws science out as reliable. Those same people have a dogmatic alternative -- beliefs and convictions that absolute arguments are superior because they don't contain self-correction and self-doubt. "I belive xyz is true so it's true. I have faith xyz is true so it's true. The purveyors of xyz never question themselves so xyz is true." If you don't allow the possibility that you are wrong then you can't be shown as wrong, whereas retrospection is weakness and proves its purveyors are inferior (or so they claim). If you do exercise introspection that doesn't make you right, though. The tough tasks are tough for a reason and no amount of stomping your foot or overshouting your competitors/challengers changes that.

I was thinking about a couple methods for deciding between competing hypotheses and you just gave a perfect example of one of them -- Hitchen's Razor. The other one is way older but still today part of the first line of many investigations -- Occam's Razor. Also, I wasn't aware that the Sagan quote you posted had it's own name: Sagan's Standard. Interestingly I read an article last week about an object that was detected passing through the solar system a couple years ago that behaved quite strangely (uniquely -- nothing like this ever seen before). An astrophysicist (from a highly regarded university) proposed that it is of extraterrestrial origin. When someone mentioned Sagan's Standard as a word of caution for the claim he poo-pooed it and countered with "It's not obvious to me why extraordinary claims require extraordinary evidence. (Rather) extraordinary conservatism keeps us extraordinarily ignorant." (!!) So apparently if investigative principles cast doubt on your hypothesis you just rewrite them to agree with your hypothesis. Oh, and it goes back to a couple points I made earlier -- 1) that philosophy of science is seldom taught even at the highest level, and 2) that (only) wise physicists understand that their thinking may be flawed. Kind of ironic that his claim of others' ignorance exposes his own, to an international audience no less. (The article I refer to can be found here.)

Are these the ones? I did find this link to another metal detecting forum (which just happens to be metaldetectingforum.com . 😁 ) Those may have been discussed here before, too (wouldn't be surprised) as many people here have searched for LL-APTX alternatives to the Minelab ML-80s. You continue to pull out some excellent finds. Wish that 1/2 real didn't have the hole. They sure were disrespectful to coins back then, but still a great find, IMO. Do you remember what the digital target ID was on that knob?