GB_Amateur

Great post, Raphis! It's these kinds of details I wish more people would express. Multiple things you said (I just quoted the sweetspot) are news to me while some confirmed what I've noticed but wasn't 100% convinced from my own observations. To find these whispers, how slow do you hunt? Can you give an estimate of how much ground you cover in an hour? I've always strongly suspected (many would say 'known' but I'm not that overconfident) that in every place I've searched there are still good targets remaining, either deeper than I've been sensitive to (and here 'sensitive' refers to the overall package of the detector and me) or masked. In both cases are there things I could do (different settings, different swing speeds, different angle of attack) to squeeze out an indication that I should dig? I'm sure the answer is 'yes' and although it won't get all of the remaining goodies it will get some. But I have to do the right things to accomplish that. I've read so many talk about VID consistency of signals, good signals from different angles of attack, no associated iron grunts, etc. as requirements to dig. Sure, sometimes I get all that, but so did most of the detectorists who hunted the same location, they just missed getting their coil over a few and those are the easy ones for me. But what about the difficult ones you describe? You answered that. There's nothing 'pure' about the signals you get from those, just hints. I got a silver quarter (only my second in 5 years of detecting) a few weeks ago and it gave me nothing I expected (VID, consistency, pinpointability,...). It wasn't even that deep (5-6 inches) although I'm pretty sure it was on edge. When I switched over to Field 2 (recovery speed 7) it was nothing anyone (well, I can't say that anymore after reading your post 😁) would dig. I think I had even covered this spot previously but I'm not sure. Chances are multiple other detectorists had their coils over it. I'm starting to understand why you've been so successful at pulling out so many coins even at the end of the 2nd decade of the new millenium. I wish you could come detect my parks and schools. I want to see what you would find and how you'd do it. It would be worth it to me to have you clean out (relative term even for you) half of my locations just to be able to learn how I can harvest the other half.

1 hour ago, GeoBill said: Serious Detecting is having a clearance sale. Looking at the Coiltek 10 x 5 Joey Mono, and the Whites 7.5 x 12 TDI HI-Q Dual Field. Did you do a search for previous posts? I Googled "detectorprospector.com White's TDI HiQ" and got several hits. Here's what I think was the original (and quite long) but there are others. Some posts talk about that 7.5"x12" dual field coil. It sounds there as though this coil was a Miner John (aka 'Razorback') creation that White's picked up, although I don't recall White's ever confirming that. If so there might be some reviews of the Miner John version out there. User Karelian has lots of experience with both large box and small box TDI's and many coils. If he doesn't respond to this thread I suggest you message him including a link to this thread. If you have the question then others do as well. P.S. It looks from the seriousdetecting website that the Coiltek Joey has sold out. 😞 You should doublecheck, though.

One thing I suspect has annoyed coin hunters in the USA for a long time is how close (sometimes equal) the VDI of aluminum trash is to that of the 25% Ni, 75% Cu 5 cent 'nickel' coin. I tend towards the "if in doubt, dig it out" camp but it has been mentioned (Jeff McClendon comes to mind) that minimizing digging can be a big plus in some parks where the employees and users notice and are bothered by any sign that digging has occurred. That's not much of an issue where I live, partly because our parks don't seem to get much attention when it comes to the quality/plushness of the grass/sod. But even I prefer to avoid digging aluminum as it wastes time and I've been hunting this year in an old park that is absolutely loaded with pulltabs. My Minelab Equinox coin hunting search mode has always been and continues to be Park 1. I notch out nothing and custom my 5 tone breaks at tone-1 ends at TID 5 or 6 (put the lowest non-ferrous in with ferrous), next tone ends at 11 (keep the foil, etc. below nickels), 12-13 only (nickel sweetspot), 14-19 (most pulltabs), and finally 20 and up (most coins along with some associated trash, most common being aluminum screwcaps which tend to be 21-23 but can fall outside both ends depending upon size and whether or not they've been flattened). One more point -- these settings are for locations where I don't expect anything earlier than Barber coins. If 3-cent pieces (both kinds), silver 5-cent (" half dimes"), or any gold coins are possible I would listen for and dig most everything above TID ~5 to not miss those. A couple months back I started using the User Profile option. At first I was playing around with Iron Bias (both FE and F2) settings, but decided for my sites and style it wasn't worth the possible loss of deep, iffy targets to warrant sufficient advantage of discerning crown caps or scraps of sheet metal (what some people call 'tin'). I don't know if they help with nails or not, but most nails that have been in the ground for a long time seem to grunt ferrous and I just live with (i.e. dig) those few that trick me. So after deciding to leave IB at F2=0 I then had an open 'slot' as to how to configure the User Profile. I decided (seemed to make sense...) that going with something quite a bit different than my search mode of Park 1 would be contrasting and might help identify good/bad targets. I went with Field 2, 50 tones, wide open (no notching). For the recovery speed setting I used Park 1's setting +2, so if I run Park 1 at RC=4 I set the User Profile Field 2 to RC=6. If Park 1 RC=5 I set Field 2 RC=7. (Those are the only recovery speeds I ever use in Park 1.) I typically come from two different angles of attack, especially in Field 2 which seems more sensitive to the shape/orientation of the target. (Important note: I always pinpoint and then check VDI's after that as I've noticed being off-center often doesn't give the most reliable VDI reading, and that seems especially the case in Field 2 when using this technique.) (Finally!) here's something I discerned after ~50 hours of park detecting: when I get a signal in Park 1 with TID in the {12,13} window (no 11's or 14's) then investigating further with Field 2 gave a 'tell' as to whether I was seeing aluminum or a USA nickel. If a nickel, the Field 2 TID would also be in {12,13} (although not necessarily identical to Park 1, in fact averaging a bit lower than Park 1). If Field 2 showed any 11's or lower then the target was aluminum. I never saw a case where Field 2 hitting 14 that was a nickel, either. (I did notice some crown caps which looked like nickels in Park 1 would hit 14 in Field 2.) In Park 1 most of my nickels are either solid 13 or (much more likely) a combination of 12 and 13. I have found a few that were solid 12. It's those solid 12's I'm most concerned about leading to false negatives, but since I've been experimenting with this technique I've found only one nickel that just nicked 11 in Field 2, and possibly I was off-center when I got the 11. I mean it was just a momentary tick, not repeatable. So false negatives (targets that this method says are not nickels but turn out to be) seem to be very rare. But what about false positives -- both Park 1 and Field 2 say it's a nickel (both are in {12,13} exclusively) but it ends up being something else? Those definitely happen. The most common in my sites are broken off (i.e. missing the ring) beavertails which have been folded/rolled over so that they mimic a coin in shape/extent as opposed to when they are elongated. Also this technique gets fooled by the smallest of the still intact ring-and-beavertails, particularly the ones without rivets. (See my avatar for an example. 😁) Warnings: 1) Most of the targets I've investigated with this technique were't very deep -- say 4 inches or less. If the signal indicates a deeper target, either from the volume of the Park 1 signal or the number of bars on the strength meter, I tend to dig if more than half the Park 1 VDI's are in {12,13} and nothing lower than 11 or higher than 14. Those occur infrequently enough that I just dig 'em. 2) This technique might be ground dependent. My soil is moderate so definitely not typical beach sand / Florida soil conditions but also not the difficult heavily magnetic type soils of some beaches and some Western USA locations, etc. 3) I don't know what happens if a coin is on edge. I need to test this in my back yard teststand which I'll put on my to-do list this week. That could throw a monkey wrench into things. 4) Here's a danger in this type of method. I thought I found another 'tell' with this technique -- largish iron pieces (not nails but things like pieces of can, pieces of cast iron pipe, say the size somewhere USA quarter to silver dollar size, but deep) could be distinguished. I found such a target which read VDI in the high 30's in Park 1 but dropped to the teens in Field 2. If I could eliminate those, that would save digging a large, deep holes (and the time involved). Then yesterday I got a similar signal (this time varying mid-20's to mid-30's in Park 1 and teens in Field 2) and decided to confirm my 'discovery', expecting a moderate piece of iron. It was an early Wheat cent (TID low 20's out of the hole)!! So how many good targets like that have I missed since "figuring out" that Park 1 high and Field 2 teens meant deep iron so don't dig?? My oversight is that I should have investigated this particular (uncommon) situation much more before reaching the conclusion that it was a good discrimination technique. Oh, we learn from our mistakes but I'd still rather not make them....

You sure went to a lot of trouble. I hope this at least gets serious consideration at ML. One thing you brought up is something I've thought about but never really vented about: I don't think it's OK, at least for my style. I'd much rather it give me the option of reducing the pinpoint signal than thinking it knows better than I do what I want. From my experience, not knowing the gain of the pinpoint response makes it more difficult to discern depth, size, shape, etc. And I wonder if that quirky loudness problem that occurs occasionally at initialization of pinpoint is related to this supposed feature. I also wonder if it leads to less usage of the pinpoint function by many users. (Several here say they never use it.) It's so easy to place the coil nearer to the intended object and toggle pinpoint off-on to lower the strength of the signal. Isn't that how most detectors with pinpoint work? This auto-recal feature seems like an engineer's idea of something cool to brag about with little concern for the in-field user. But you've recommended two modes -- one with and one without auto-recal -- which would suit me just fine as I could then leave auto-recal off (forever!).

The base on that jug looks like it would lead to it being tipped over easily. That makes me wonder if it's rare. Great finds all the way around!

The chances of finding one of these with a detector must be pretty small. First off, they are scarce to begin with. Secondly, there hasn't been much time for them to have been dropped. Chances are greater than zero, though, and if you're recovering them anyway you have nothing to lose by checking the date+mm. Certainly in my detecting grounds they will still show the bright nickel color as opposed to the gray/red appearance 25% nickel alloy develops after some years in the ground. I don't know about ones found in water/muck as those conditions seem to lead to different surface development. I wonder if the mint had second thoughts when the covid-19 shortage developed this year.... I don't mean people pulling the -W quarters out of circulation but the possibility that the search for them made it more likely that people kept quarters instead of recirculating them. Probably still not much of an effect relative to the other causes. On a related note, I wonder how many detectorists check their copper Memorials for the 1972 double die.... Ditto the 1969-S dd but that would be like finding a needle in a continent sized haystack!

https://www.usmint.gov/news/inside-the-mint/mint-releases-first-ever-w-quarters-into-circulation I like this quote from that article: "The goal of the initiative is to create excitement about coin collecting by introducing rare coins into circulation, allowing anyone the opportunity to collect the quarters from their pocket change." (emphasis mine) How things have changed since 1965 when the USA federal government tried their best to kill coin collecting among the common (i.e. non-wealthy) people by no longer using mintmarks and stopping proof coinage. (Of course that is when they stopped minting 90% silver coins and started the ugly clad coinage, but that was because the silver coins' cost of minting was higher than face value.) Mintmarks returned in 1968. Are these first non-error coins meant for circulation minted in the last 60+ years which carry a premium value (over face)? I'm not aware of any others but I lost interesting in modern coins (except for some of the double dies, etc.) long ago just for that reason.

It's not sufficient that they read the suggestions. They need to consider them seriously. Have they done that in the past, and more importantly will they do it this time and into the future? I don't know on the positive side, but if request for accessory coils is any indication I wouldn't be holding my breath thinking what we (or Tom's site members) ask for will end up anywhere but the circular file.

When you're on a losing streak you want to make sure it's not because there aren't any more good finds out there. I've been in a slump since mid-summer and haven't posted any finds. I'm saving the few I've had for an end-of-year summary post. (Found a silver dime today so it hasn't been a skunk, just few and far between compared to first half of the year.)

GW, you mentioned in another thread that you are an engineer and like to tinker. You also asked about books. Here's one that covers both bases -- Inside the Metal Detector by George Overton and Carl Moreland. There's an (early) chapter there on making a pinpointer. The book is probably going to cost as much as a cheap pinpointer, though. One thing about some of the cheapos - they are pirated/counterfeit copies of bonafide models. They would be illegal (for the makers/sellers) if they could be prosecuted (or should I say, if they could stop them in their tracks). You're safe buying one of those (I'm not saying all inexpensive pinpointers are counterfeits) but you would effectively be encouraging the crooks at the expense of the deserving manufacturers.

Unless you just have 3D printer cycles to burn I would hold off on this. Do you think you can make them as lightweight as those supplied/sold by Minelab? You mentioned counterweight to improve the balance. If you can't make them as light as are available it seems you'll be going in the wrong direction there. I've never burned through a coil cover but I don't spend a lot of time in rocky or abrasive surfaces. If your beach eats coil covers you'll need a replacement eventually but why not wait a while and see how the stock one holds up? Garage mods are fun, but if that takes away from your detecting time it seems counterproductive. IMO, get out there and use your detector. You may find some obvious weak points that drive you to mods, and you'll be in better position then to know what you need. Anything that risks voiding the warranty isn't a good idea, particularly early on when you're more likely to need the warranty (meaning most factory weaknesses show up early on). But you probably know all this, so just a reminder.

I don't see the connection between the posted, photographed item and the linked page, except that both are jewelry with threaded (machine screw) fasteners. Was this the link you intended to post, kac?

Now that's an impressive display and story! It does bring up a point few of us will ever be fortunate enough to be confronted with, but this detectorist should (and maybe did) think of it: If something is rare but sought after and you were to discover a hoard of it, how do you publicize and liquidate? The law of supply and demand in its simplist form says when the supply goes up the price comes down. Thus if these were $100 each (3-piece bullet) before this discovery, is the demand high enough (or can it be built) to keep that price/value? (You didn't say where the $100 valuation came from so I'm using that value for illustrative purposes.) Example 1: in the 1970's the USA government (Government Services Administration or GSA) sold uncirculated Morgan silver dollars that had never been distributed/circulated after over-mintage. Many were from the Carson City Mint which had never produced very many in any year. They effectively flooded the market for certain issues -- 1882, 1883, 1884 in particular. Someone who had previouly held one of these -CC minted coins in uncirculated condition (and possibly having paid serious $ for them) saw his/her prized piece drop in value to ~$30! Example 2: The SS Central America sank in 1857 off the coast of North Carolina in a hurricane. Besides passengers (don't want to undervalue human life) it was carrying freshly minted gold coins being transported from the San Frandisco Mint (~5,000 Double Eagles dated 1857 and ~1,000 dated 1856 -- see PCGS site and look at the notes at the end of the individual coin's page). It was found in 1988 and many of those gold coins were previously quite rare, at least in uncirculated condition. (Note: I don't know the details, and often the sellers try to generate value from the provenance -- "authentic, certified from the SS Central America hoard!" -- but I suspect those holding coins with those date, mintmark, and condition prior to the wreck's discovery weren't thrilled with the recovery.)

That sounds like a colassal waste of $. Graphite paint has already been mentioned, and except possibly for durability it seems from a practical standpoint it ought to be as good. I'm a bit skeptical that trying to shield the coil will have much impact on EMI, but I do like the experimentation you guys are doing. Just make sure it's reversible. The cable is coaxial (braided outer shield conductor) which is killer shielding. The control box isn't as easy but Simon has shown it can be done and that the manufacturers already do a good job at least in some cases. But the coil itself is meant to receive RF -- that's how/why it works! BTW, you can buy metallic copper tape with conductive adhesive (make sure to get the conductive adhesive since they make versions with non-conductive adhesive) which might be worth playing around with. However, it might not be practical to take into the field for hours as it will increase the weight of the coil much more than aluminum foil, for example. I wish Carl would see this thread and respond. He could probably short circuit some of these ideas, but then he'd take away the fun you're having. 😁

Welcome, Glasswalker! Your wife made a fine choice in getting you a Vanquish 540. It's a very good performer but not so complicated with settings that you'll get it tied up in knots. You've definitely come to the right place, and I wouldn't worry about silly questions. I've asked a lifetime's worth of questions and no one has ever derided me. That just doesn't happen here. I'll be watching Curse of Oak Island in 45 minutes myself. Yes, there are some New Zealand detectorists here and I'm sure you'll get some advice. I don't know how many (if any) are from the North Island but I think they've visited there (maybe with their detectors) and even if not they'll have some local tips for you. Enjoy your reading -- there's plenty to keep you busy every day until Christmas.

Do you really mean tin or do you Kiwis (and/or Aussies) consider that a synonym for aluminum? 😉 If the layer is thin it could flex (e.g. in the wind) which is going to mess with the performance. You can buy copper sheet here in the USA from companies like McMaster Carr (heck, maybe even Amazon) in thicknesses that will be remain more stationary than store-bought aluminum foil. You make it sound like you've tried this. In another recent thread (also see this one) it was touched upon whether altering the field above the coil would help getting under a metal fence. (In fact is was your thread!) If your proposed experiment really works is it a solution for the under-the-fence problem?

Great, detailed writeup, Simon. I think you pretty much 'shielded' (err, covered) the entire subject. I think the primpary purpose of the conductive coating on the inside of the coil housing is to minimize/eliminate electrostatic buildup affecting the performance, e.g. from the coil's housing rubbing vegetation, etc. When I modified the 150 (mm) coil for my White's TDI/SPP which included replacing the bottom half of the enclosure I had to paint it with conductive (graphite loaded) paint. It's been a while but I think I added coats of the paint until it reached a certain resistance/resistivity. I assume that is what they do during coil manufacture except they shortcut my process by knowing how many coats (how much thickness) are required to attain that R/rho.

I was thinking the same thing. kac, does that mean you are calling me stupid? 😠 Maria, another possible solution is to buy them, investigate, and then decide whether or not to gift them to your friend. If the cost is significant (to you), that obviously taints this option unless they can be returned for a refund.

I think that illustrates an even more fundamental problem than addressing detectorists' intended targets -- the difference in meaning between 'tries' and 'succeeds'.

That's certainly evidence and thanks for providing it. One thing, though, is that so far you are comparing two different detectors even though they have a lot of DNA in common. Better evidence would be F75 pre-DST model vs. F75 later version which was labeled 'DST', which I realize is a comparison you aren't in position to make. Also something I didn't see in your posts is whether you've looked for depth differences for your F75 with DST engaged and with it disengaged. I confess I've never tried that; in fact I've always just operated with DST engaged. Unfortunately (to some extent) for me I came along after all this was hot news in the forums. I do recall some mention of it here previously, but that mention included some skepticism as well, if I remember correctly. Maybe our forum here wasn't even around when all this was the hot topic. Although I'm pretty adamant in following this site, the others I only touch when I'm researching a particluar topic (e.g. how a particular brand's coil I'm interested in performs on a particular detector) or someone here links to an interesting thread.

I can turn off DST on my Fisher F75 Black ('Limited') w/DST. In that case do I restore the depth/sensitivity loss back to the pre-DST version? Yes, First Texas is the right place to direct this question. I just bring it up because I don't think it's as simple as F75 model without DST being more sensitive/deeper than F75 model with the DST option. But if there is evidence that my and similar units (with DST that can be toggled on/off) go deeper with DST off than when it's on, that would be support for your claim of shielding reducing sensitivity/depth. I'm pretty sure some have said that's true and maybe it's convincing enough to seal the conclusion. I've not looked into it myself (neither in testing nor in researching YouTube, etc.). And even though I've read the manual several times, all I remember it saying there is that the user has the option of turning it off. I don't remember it saying "to get more depth...".

Is this an anology: does the wind affect the sail, the hull, or both? I think the answer to both questions is the same -- stronger effect on the sail but under certain circumstances (e.g the sail is furled) then the effect on the hull is noticeable. OK, the analogy isn't quite perfect, because who would ever (intentionally) operate a metal detector with the coil detached? However there have been situations here where people have reported interference when an electronic device is close the to control head but moving it away even a small distance improves things. As a side note, IMO there is a risk in asking for expert answers. Define 'expert'. If you leave it up to the individual then you will drive away people who are expert but also modest while at the same time keeping those who aren't expert but have unrealistic egos. In my case, for another analogy I (mis-)quote the old Holiday Inn Express commercial: "I'm not an expert, but I did read detectorprospector.com last night."

Do you have a tumbler? Wouldn't the non-Zincolns clean up in a tumbler well enough to be accepted by the coin counting machines? I think the one strongly recommended here (Lortone) is well within your budget now.

I've never seen that illustration but it sure explains a lot. ("A picture is worth a thousand words!") Thanks for posting that, Chet. Where were you guys when I needed you? 😃 That's something I had to learn the hard way but I was never really sure that I was arriving at the correct conclusion. My recovery technique of digging around the target and removing a clump of dirt containing it (to make sure I don't hit a desirable target with the steel digging tool) erases the orientation information. Thanks to both of you. BTW, "a few coin detectors" includes the Minelab Equinox, at least with some settings.

That's really slow, but they put it there to be used and if it's working for you, that's what matters. I haven't experimented below 4 and lately I've been running either RC of 5 or 4 in Park 1 for coin searching. I run Field 2 with recovery speed 6 or 7 (Iron Bias F2=0) in user profile mode to investigate targets.