GB_Amateur

Here's an experiment for every Equinox user. Auto noise cancel. Then do it again. Do you get the same channel?

Nice! Lot of detail on that pendant, and I wonder why the double loop attachment. To my eye this looks a little large (and probably too detailed) to be from a charm bracelet. Hope you're being careful with that pick. I take it the ground is really hard and rocky.

If we're (really) lucky there will be some reliable info at the Detectival event in 3 weeks:

Sounds like you're in the right spot! You didn't say if you've been searching the freshly opened area or the piles. You also didn't mention the age of your finds. IMO, it's the old finds that are more difficult to find in general so go for those, even if less plentiful. Consistent with Noah said about time being of the essence, I would concentrate on the cleared area and get to the piles later (if the latter is even possible). It will be interesting to see if there is anything in the ground after they clear the next 12 inches. It could go either way, depending upon the history of this location and the density of the ground. My suggestion (similar to Noah's) is to not waste any time. Sounds like a lot of area to cover and they aren't going to stop and wait for you to finish.

In retrospect ("hindsight is 20/20"), IMO they should have labeled the recovery speeds on the 600 simply {2,4,6}. But I suppose then someone would have wondered why there was no {1,3,5}. FWIW 90% of my hunting has been in the {5,6} region and only recently have I tried 4 (which has produced some good results). I don't think I've heard/read anyone running with recovery speed = 8 although I know it's been tested and likely some have given it a whirl in the field. When I run in Field 2 mode (where 7 is the default) I just turn it down to 6. But just like the gain/sensitivity (where I almost never go above 22), it's nice to know I have the capability of pushing to the extreme. Minelab kept that option in the recovery speed for the higher priced 800. One of those marketing decisions...

And no offense was taken. I could have started out with a disclaimer instead of waiting until the end. Often, though, it seems like beginning with a defensive statement taints the rest of the post. If people only read the beginning and then exit they miss that last part. In this case I trusted that wouldn't happen. From the 'early voting' 😁 it appears others agreed with the need to explicitly state the simplicity aspects of the detector as you did. So you provided a valuable service.

Thanks for the link, Mitchel. I went back and reread it (probably need to do that again) and, yes, once the new (May 2019) replies start talking about the X-coils the informative discussion gets derailed. Being the contrarian that I am, though, I'm reminded of Dave Johnson's article: http://www.fisherlab.com/hobby/davejohnson/SearchcoilfieldshapeApril2012.pdf where he warns: So to say what happens when you swing a target past the searchcoil of a simple motion discriminator requires computation of at least 26 variables. I doubt anyone has ever attempted to compute such a thing, although it’s theoretically possible. In any case, nobody will ever draw a picture of it. Kinda like quantum physics. You can get a pretty good idea of what's going on with a good verbal description, but to really understand it you need to get into the weeds (higher mathematics). Just like detecting. It's hard to swing a detector in the weeds, but sometimes that's where the really good targets are hidden. 😁

Realistically you don't need to search thousands of settings to find the optimum one. (I was really thinking about testing -- when you don't know what the site will be so you try and anticipate or even cover all possibilities.) In practice at a site you set one feature and then move on to the next, sequentially. (You could and maybe should backtrack in some cases, such as sensitivity and noise cancel as those two can be intertwined.) I thought of an analogy: Suppose your sight is limited (e.g. in a fog) and you are tasked with reaching the top of a mountain peak. You have a compass and an altimiter. Follow an N-S path until you max out the altimeter (when it's starts reversing you backtrack to its max). Then change to an E-W direction and do the same. If the mountain is simple (single peak, no valleys) you will find the top after these two steps. With a detector, each setting is analagous to the N-S / E-W path so you can have more than two (more than two independent dimensions). In reality, mountains aren't always so simple -- they have multiple peaks, saddles, valleys, etc. A metal detector isn't a simple mountain, either, but you can do pretty well most of the time if you assume it is.

Oops. That's a big one, something like a factor of 8 (correction, 3). Good catch. (Note: calculations have been corrected in original post to reflect this.) Is recovery speed adjustable in single frequency?

As users know, there are a lot of setting options for the Minelab Equinox 800 (ditto for the 600, although not as many). But how many affect the detector's performance and how many fall in the category of ergonomics? I'm going to divide the settings categories into three groups: those whose adjustment is standard fare, those whose adjustment procedure isn't obvious but can clearly affect the performance, and those which are more/less ergonomically oriented. This is just my simple classification. You can redo my calculations if you feel that one or more features belong in a different category, or if practically you can ignore a range of settings. So here goes: 1) 'Standard fare' adjustments: a) Noise Cancel, b) Ground Balance. 2) Performance affecting options: a) Detect modes, b) Operating frequencies, c) Sensitivity (Gain), d) Recovery Speed, e) Iron Bias. 3) Ergonomic settings: a) Overall Volume, b) Threshold Level, c) Threshold Pitch (audio frequency), d) # of Target Tones, e) TID breaks, f) Target region tone pitch (audio frequencies), g) Target region tone volumes. Let's start with category 2 above and include all possible settings. The first two combine because not every frequency option is available in every Detect Mode. By mode: i) --> iv) Park 1, Park 2, Field 1, Field 2: 6 + 6 + 6 + 6. v) --> vi) Beach 1, Beach 2: 1 + 1. vii) --> viii) Gold 1, Gold 2: 3 + 3. So total mode and frequency options is the sum of all these = 32. Next is gain, of which there are 25 possible settings. Then recovery speed = 8 settings. Finally Iron Bias = 10 settings. Thus we now can mulpultiply these: 32 modeXfrequency * 25 gains * 8 recoveries * 10 IB's = 64,000 possible setting combinations! Can we simplify? I think somewhat, yes. Although there are 25 gains settings, probably the lowest 10 can be left off for 99% of search locations. So replace 25 with 16 and were down to 41,000 (rounded). Now I feel better. 😁 Correction: Chase Goldman (response later in this thread) points out that Iron Bias setting only applies to Multi-frequency, not to the single frequency selections. The 64,000 number above (assuming 25 gain settings) is actually 20,800 and the ~41,000 (assuming 16 gain adjustments) decreases to ~13,300. There are a lot of ways to play around with this number. Some will say that gain is simply a 'standard fare' adjustment since you set it to the highest level that background noise will bear. But that is oversimplified in a trashy environment since targets (particularly ferrous vs. non-ferrous) are affected differently. The flipside is that ground balance sometimes isn't optimally set (at the neutral point) and forget. Native gold detectorists sometimes find better performance when adjusting a few ticks off neutral. Number of target tones (and also target pitch and volume) can play into performance in a practical sense since the human brain can take advantage of (or be adversely affected by) these. You can think of (and set) the Equinox 800 as a simple detector. Just choose your favorite mode and then go with the defaults. This isn't new, the same can be done with the White's V3i (although if that's your plan with the V3i then save a few buck and get the VX3). But to get optimal performance you need to adjust the detector to the conditions, particularly site. There's a lot of space to cover and it's not surprising that 1 1/2 years after its release people are still finding settings that beat (in certain environments) the canned (manual suggested or otherwise determined) settings.

I guess there are two ways of answering this first question: 1) How far away do you need to be to avoid cross-communication between detectors? Answer: you'll know it when from how your detector reacts -- is it picking up EMI? Many detectors have frequency shifting (allowing small incremental changes to operating frequency) to alleviate this issue. Otherwise just move apart until the noise stops. 2) How far away should you be to not be a distraction to each other? This one is unquantifiable and clearly depends upon the individuals. When I go out with my sister I usually just head off one direction and she goes another and after awhile I'm looking around to call her over and I can't even find her. 😁 Unfortunately it seems the online reviews (any reviews) of pinpointers is much sparser than standard detector reviews. I would search google with keywords "minelab" "pinpointer" "detectorprospector.com" and find some discussion of that particular model vs. its company brethren. That will hopefully get you the experiences of others on the relative merits. You can leave off this site in your search which should get other sites' discussions as well, but I would start here. Bottom line is that there are many decent pinpointers, many with different characteristics and none perfect. I like my White's TRX better than my Garrett Carrot (Propointer AT) in general, but in some cases the Carrot is preferable. And that's just two of the many models out there. If I could afford it I'd own one of each, but then I probably wouldn't have time to test them properly and that without eating into my limited detecting time.

Good point, and it shows one of the weaknesses of this setup. I did bury two coins (US 5 cent 'nickel' at 6" depth, US 1 cent bronze at 5" depth) for calibration/sanity-check purposes. But those can have their problems, too, such as the depth and orientation changing over time. I will point out that three engineers most of us have heard of (Dave Johnson, Carl Moreland, and George Overton) are skeptical that the halo effect even exists except for possibly iron. But that's a whole 'nother discussion topic and doesn't need to be elaborated here. In the end I think any controlled setup has its limits compared to real in-ground targets. But I do think (and I see you and many others agree) that it's still informative and worth the effort.

I started this project 2 or 3 years ago (so long I can't remember). Spurred on by recent field experiences and also a recent thread on Equinox settings I've finally finished it. I don't know if it's a completely new idea. I call it a 'test-stand' as opposed to 'test garden' just to distinguish it from the standard test gardens many of you either already have or at least are familiar with. There are other similar variable depth test gardens out there (seen on YouTube). This one has the advantage of continuous depth capability. It also allows 3-d target orientation angle (similar to pitch, roll, yaw of airplane). It's based upon the 30-60-90 triangle (remember that from geometry/trigonometry class in high school?): Here is a sketch which shows how to implement this concept: Shown in the sketch, buried at an angle, is a PVC pipe. A test target can be slid into the pipe a distance 2*d which will result in it being located at depth d. I used two sections of pipe (ID = 1.57 in., OD = 1.90 in.), side-by-side to allow me to put neighboring targets in the ground with some option of how close the two targets are separated. Think of this as burying a double barrel (side-by-side) shotgun with the stock end deep in the ground. All you see are the ends of the two barrels. The concrete (bag of Kwicrete) locks the pipes in place. Here's a closeup of those extruding barrels: Besides the tape measure (units of inches) you also see a hand-graded scale at left which I'll explain shortly. Here is an overall view: The two PVC caps, attached together, are for keeping water, dirt, and varmints out of the pipes when not in use. You'll notice a 1.5 in. diameter wooden dowel rod inserted into one of the pipes. More detail on that shortly, but the target is inserted into the dowel near its end and then the dowel is slid into the pipe. Holes for locating pins (you can see one of those -- gray plastic -- inserted to register the intended depth) are 1 inch apart leading to a depth resolution of 1/2 inch. (Again, refer to the 30-60-90 diagram to understand the relationship between insertion length and actual depth into the ground -- a 2::1 ratio.) Next I show the business end of the dowel rod: The black foam fills the chamber and holds the target (in this case a silver dime) in place. The hole in the dowel is actually lined with a plastic film canister (remember those from 35 mm film days?) which has been modified to conform to the circular cross-section of the dowel and thus be able to fit into the pipe. The second slightly smaller) large hole was put in there originally for a second target but so far I haven't used it -- likely of limited value. You can see the registration holes. The first one has a red '2' (difficult to see) just above it; the next (representing 2.5" depth) isn't labeled; the third one has a '3'; etc. These represent the resultant depth of the target when a registration pin is put in that hole and then the rod slid into the pipe until the registration pin keeps the dowel from going deeper. Although the chamber packing material can be made up of many materials, I chose ethafoam (polyethylene foam) high quality packing material. You typically find this in higher end electronics packaging such as with desktop computers. More commonly it is white but in this case I used black. I initially cut plugs with hole saw (see next photo) and then trim with a pocket knife as needed to fit the pipe: Ok, so now you're still wondering what that specially graded (homemade 'yardstick') is for. Again, referring back to the 30-60-90 triangle drawing, the 3rd side of the triangle is also related to the depth. It is squareroot of 3 times the depth. (Squareroot of 3 = 1.73.) That yardstick will indicate how far downrange (along the ground surface) that the target is located. This helps when you get an iffy response on your detector and want to confirm or deny that the surface location of the target is consistent with its depth. The units written on the scale are associated with the depth of the target. You can see from the sketch above that the max depth is 15". The largest common US coin that will fit the chamber (with some force...) is a half dollar. I didn't keep track of the cost but it's probably $30 or so, mostly for the PVC pipe and caps and the dowel rods plus a bag of Sacrete. (I'm counting labor as free. 😁) OK, now that I (finally!) finished this test-stand it's time to get busy making measurements. I'll be posting those here on the forum as they become available.

Here is that Mars telescoping shaft at Serious_Detecting ($120 in US). "Fits 50 different machines" (see the list): https://www.ebay.com/itm/Mars-Black-Telescoping-Universal-Metal-Detector-Shaft-Fits-50-Different-Machines/282164405709?epid=1583419790&hash=item41b24f25cd:g:kNMAAOSwzkRdHNSs:sc:USPSPriority!47401!US!-1

Decided a bit of followup is in order as my post left some things up-in-the-air. (Thanks for all the thoughtful and helpful responses.) I haven't gotten in much hunting time since that 1850's homestead weekend for various reasons. But the two new locations (both public parks) I have searched have given me little to no EMI problems. In one case I just set the gain to 20 but did run it up to 22 and didn't get any interference. In the other case I ran most of the 4 hour session in Park 1, gain 22 and even tried 25. Still no noticeable EMI! Neither of these parks is located in my hometown where I've done 99% of my coin hunting. So, what's going on? I think underground power lines are the main source, with possible additional headaches from private radios (like they sometimes or at least used to have at construction sites). There are so many sources of problematic EMI and as others have pointed out, they vary a lot by location and even by time. My hometown has long ago converted from overhead power transmission to underground, and I'm sure the depth at which they are buried is a factor. In my cases there are likely other variables, too. As far as why I don't find coins deeper than about 6 inches, I think I'm getting a read on that now that I've installed my test-stand. I'll post more evidence as I collect it, but from what I've seen so far, it is the ground magnetic susceptibility affecting the TID. (Sound familiar? Steve just mentioned this with regards the using TID for dig/no-dig decisions when using the Eqx for hunting native gold.) My current thinking is that the TID drops as depth increases and I'm mentally rejecting (discriminating against) low tones. (This problem isn't unique to the Eqx and might even be universal.) Stay tuned.

I don't remember that specific ad but there were multiple 'build your own' articles you could start from scratch, as well as a few kits. See this thread where I pictured my (broken) Heathkit GD-48. (See this Findmall thread where someone posted a tantalizing but incomplete schematic. Phrunt will be building one, now. 😁 Link deleted since Findmall Forum update broke all old links . Those come up on Ebay frequently. Apparently injection molded plastics were still in their infancy(?) since the housings (control unit and searchcoil) were flimsy and broke easily.

No, Jeff, you got it right the first time. It is thousands. 😢 Add another vote for the green patina. My IH's usually have scale which is much more detracting but so far I haven't figured out a good way to get that off. ('Good way' means still maintaining a natural color and no scratches!) Another project for the upcoming winter. Nice find, Valen, and thanks for the pic!

You wrote that in the past tense. I don't believe it for a second!

Well, maybe. Does hanging out with you (and your motley crew of instructors) in the Nevada desert count??

Welcome, nature lover! Keep us informed on how your home-grown detector works out. Do you have any mass manufactured detectors to compare it to?

Welcome, Joe!. Being from such an historically important location I can see why relics has been a key search target. I assume you've found some very old coins in the mix. Hope you make it to gold-rich Arizona, if not permanently at least for some long (vacation) hunts.

Pretty sure the 'low loss angle' refers to the phase shift (related to target ID). I think that shows up as the ground reading (phase) and setting. But the magnetic susceptibility is the property that leads to loss of depth. Maghemite also has high magnetic susceptibility. When your manget picks up black 'dust', that's magnetite. When the attracted dust is brown/tan it's maghemite. At least that's my simple minded view. BTW, I could never remember the word 'maghemite' until I just read (while researching my above post) that its first two syllables are 'mag' (from magnetite) and 'hem' (from hematite): mag-hem-ite. I don't mean to downplay the presence of iron as causing problems. Even "mildly ferromagnetic" material can affect things if enough is concentrated. It's the ferromagnetism that is the issue. Iron in some compounds isn't ferromagnetic. It just depends upon the form (compound) of iron, and there are many different types in nature.

Here's the original paper: https://pubs.usgs.gov/pp/1270/pdf/PP1270_508.pdf It's worth noting that the map shows iron concentrations totalled over all chemical forms, not just the insidious (to detectorists and other gold recoverers) magnetite. From Wikipedia: https://en.wikipedia.org/wiki/Iron_ore Although iron is the fourth-most abundant element in the Earth's crust, comprising about 5%, the vast majority is bound in silicate or more rarely carbonate minerals (for more information, see iron cycle). The thermodynamic barriers to separating pure iron from these minerals are formidable and energy intensive, therefore all sources of iron used by human industry exploit comparatively rarer iron oxide minerals, primarily hematite. Thus magnetite isn't even the most abundant oxide of iron. (Hematite is only weakly ferromagnetic. See: https://en.wikipedia.org/wiki/Hematite#Magnetism) I bring all this up because the Fe3O4 (magnetite) scales on the Fisher F75 and Fisher Gold Bug show iron concentrations considerably less (by roughly a factor of 10) than those in the map Skokum included above. The detectors actually measure magnetic susceptibility but the results are reported in Fe3O4 equivalent units. (See: http://www.fisherlab.com/hobby/davejohnson/DavesGoldbook-reders.pdf especially pages 12-13 and 24-26.)

Good hunt! I agree with John Doe. Old silver (including old Canadian) is better, but new silver isn't easy to come by, either. That pin looks pretty neat. The 'H' has an old look to it. Could be a (moderately) new pin that was made to look antique, but I suspect it's authentically old. Hope you can do some research (even contacting Harvard if internet searching doesn't get you the answer) and find out its age. I'm certainly curious.