GB_Amateur

Hey, Joe. I know Westminster (used to live at 72nd & Samuel Dr., but that was long ago in 1980) and I know the feeling of warm weather turning to bitter cold overnight. Do you belong to the Eureka Treasure Hunters Club (http://www.eurekathc.org/)? Still wonder why modern detectors don't have bigfoot (style) coils as an option. They're "no contest" in contests, and sounds like they do great with recently dropped treasures.

One button to toggle between all-metal and discriminate. Got it right = Minelab X-terra 705. Got it wrong = Fisher Gold Bug where you have to re-adjust threshold of all-metal every time you change from discriminate to all-metal. What were they thinking? (Except for that I love my Gold Bug Pro.) If knobs are installed, they should either be a) out-of-the-way, or b) lockable. Got it wrong = Whites TDI (which otherwise I really like). Got it right = ?? Both screen view and (multi-tone, at least for coin and jewelry; less important for native gold) sound have their place in my toolbox. Since I wear bifocals, it's straining on my neck to have to look down at the screen too often. But seeing a 2 digit ID is helpful (really like GB Pro full 2-digit 1-99 discrimination scale). As far as screen readout features, I'd sure like to try out the Whites V3i with all its bells and whistles. (Again, these features are more valuable to coin and jewelry hunters.) You hear/read plenty of "don't need that; never use it", but detecting in iron infested sites I'd like all the info I can get. Weight -- keep it light!!!!!!!!!!! If I can find a detector that does the job, even if not the absolute best job, I'm likely going with it (and I have). So far my arsenal has a 3 lb max limit (at least for small coils) and I'd like to keep it that way. Got it right = many (VLF's) and Whites TDI/SL (PI). Balance -- does anyone make a detector with adjustable balance for when coils are changed? Movable control box, movable battery box,.., seems like there are ways to do this (and in fact I have when tinkering with my TDI/SPP).

Excellent video, and of course appropriate to many branches of metal detecting. I always try and determine the age of finds, not only because, as mentioned in the video, to improve one's knowledge -- leading to improved quality of finds -- but also because I enjoy history. Sometimes we're lucky enough to have dates (besides on coins), often patent dates. Most of the time, as in the video, it comes down to figuring out when an item was in common use. One of my favorite trash finds in parks is the ring-and-beavertail pulltab, which dates its loss to the 1965-75 time window (as Jason mentions). Because older detectors weren't so good at discrimination, these should have been dug up back in the 70's-80's and even 90's. Even with today's detectors, because the r&b pulltab shapes vary (with bending and broken off parts) the ID can vary enough to overlap coins, especially if you're in a site which might have the full range of 19th Century US coinage. Bottom line is if you find trash others should have found, then either you're doing something different (and better) than what they did, or they haven't even been there. Win-win!

Glad that worked for you. Here is what it says in my Garrett Pro-Pointer AT (aka "carrot") owner's manual: "When the battery becomes low, the detector will sound an alternating dual-tone alarm. Replace the 9V battery as soon as possible." Sounds simple and obvious. Except users such as yourself, Cabin Fever, my sister, and I have all experienced different behavior than the manual describes, then changing the battery and having it be just fine afterward. Apparently it starts acting flaky before the battery is low enough to cause the unit to emit the dual-tone alarm. Great device; don't leave home without. But be careful getting it too close to your horse's mouth!

I think you can safely replace the word 'Geotech' with 'internet' and everything else you say is 100% valid, IMO. Unfortunately there isn't a 'driver's test' required before allowing someone to use it. And we're seeing the results at an alarming level.

Informative review of all kinds of rechargeable batteries: http://michaelbluejay.com/batteries/rechargeable.html Might answer some of your questions.

http://www.metaldetectingworld.com/make_metal_detector_wireless.shtml Here's a decent article, written some time ago (I think last updated in 2014) which talks about the state-of-the-art at that time and a homebuilt solution similar to Goldgetter's above. Since then we have more universal, commercial solutions such as Deteknix and now Garrett products. Last year I considered going the Sennheiser route but decided Deteknix was just as cheap and I wouldn't be "rolling my own". Now I'm going to get the Garrett and use my own (comfortable!) headphones.

Not trying to clog up the forum with ebay item(s), but this looks like a hard-to-find item someone here might want: ebay.com/itm/18-Cannon-Coil-For-Whites-TDI-Metal-Detector-/2 Never seen one of these myself and have never heard of this company (if 'Cannon' is actually a company name -- maybe it's not). Says 17 microsecond or longer delay is recommended, which takes it out of my wheelhouse since my TDI/SPP is locked at 10 us.

However you decide to structure this, I'm in. The best things about this forum are the no nonsense postings, the discouragement of arguments, whether motivated by politics or personal feuds, and the factual/scientific/engineering nature of the information. There are plenty of sites on the internet where people can argue and opine with little or no basis of evidence/fact. I don't care to waste my time there. Frankly, some of the related magazines and newsletters (online and in hardcopy) spend too much time on these incendiary topics, which, IMO, simply galvanize the supporters for at best no improvement in environment while at the same time driving away the potential new blood. Steve, you do a great service for zero compensation. Please keep it up. Metal detectors and detectorists have many things in common, but typically have their favorite/preferred strengths/areas of interest. Anything that can be done to support that diversity while at the same time cementing the common interests has to be a plus.

If I understand the question, the two battery cases are similar, but the orange pack is a sealed NiMH pack whereas the blue case is the user-loadable 8xAA holder. So I would use the blue one.

And you can turn it off. That's a huge safety plus for a particularly strong magnet. You can also control the field strength. Should be lots of info on the web on what it takes to build one.

I'm confused about the last parts of this, specifically: "...almost a wash..." and "...an inch or so difference..." A wash comparing what, and a difference comparing what? You mean a TDI/SL as currently configured compared to a TDI/SL with the proposed new battery, or the TDI/SL with the proposed new battery compared to the current TDI Pro?

You already hit the weight and price advantages. Simple to use -- turn on and go (after ground balancing, of course, but that is quick). 1) I'd like to see a small (e.g. 6 inch diameter or equivalent elliptical/butterfly), negative or neutral buoyant coil for underwater crevice/crack searching in shallow creeks. Maybe the new Detechs fit that bill? 2) How about a battery pack that runs higher potential than the standard issue -- ~16V? If I understand what others have said/written, there isn't a voltage regulator off the power supply and higher voltage means more sensitivity. If so, some of the limitation mentioned by Glenn will be alleviated. If this enhancement is possible it requires no modification to design so no increase in base cost. Maybe a bit more weight but it could still be the lightest dry land PI, I think.

I started out with 4 tones but switched to the max multitone after reading Horton's monograph. I'll try the lower number of tones again, but my recollection is that I first noticed wraparound in the early days (4 tones). I'm going to play with the gain setting and see if that helps. At some point I probably could/will learn to live with the wraparound -- others have done that (and more). I'm still not very experienced with the modern detectors so I'm not discouraged, just anxious to get outside and play again.

This thread was almost dead and buried a day ago and has sprung back to life in a big way. Lot's of good info and explanations -- the main reason I monitor this site, to learn so I can become a better detectorist. With repeated hints I think I'm (hopefully) starting to see where I've been going wrong. Apparently gain settings have a non-linear effect on the wraparound 'problem'. The full scale of the gain on the Minelab X-Terra 705 is 30 but I always have gotten noise (maybe EMI, kinda sounds like that) the few times I've set it there. I typically run in the 25-27 range and the detector seems to be nice and well behaved in that zone. But it's sounding like I'm fooling myself. I tend to think in the analog world, but this may be the source of my problem. Turn down the gain and everything is affected the same way -- that has been my thinking. Iron is still there; copper, etc. are still there, wraparound is still there, just with less strength and/or sensitivity (and the fear sets in -- with corresponding loss of depth). In the digital world all that is so overly simplified as to be dangerous. The other thing I've wrestled with is this: if iron gives both low conductivity (as it should, or at least as we want it to) and high conductivity signals, how do you distinguish that from two separate but independent targets, for example a nail and a coin close together? In my case it hasn't been so simple that the high signal is above coins -- sometimes the TID (VDI) is right where a real US coin is located. I notched off 48 (0.999 fine silver coin) and still got positive response. I notched off 46 (US silver dollar) and still received positive response at 44 or lower. The good news is that I've installed a testbed in my backyard with variable depth and separation capabilities (I promise to make a post on this sometime this winter giving the details -- it's not your typical test garden). When that is completed I'll be able to do a lot of experimentation and hopefully figure out the difference between simply iron wrapping around and two separate targets, one of which will reward me for digging it up. Stay tuned.

In fact I have notched off the highest (most conductive) bin, 48, which I think is where pure silver (>99%) would hit, But that hasn't been enough. I've had to notch off the next bin (46 = US silver dollar?) as well. Also, you mention "large iron" as being the culprit. The word "large" is, of course, relative. But I get wrap around on 1 inch (2.5 cm) long nails. Randy Horton also prefers the coin/jewelry all-metal mode as opposed to coin/jewelry with notching. (And for those not familiar with the X-Terra 705, these are both independent of the unfiltered(?) prospecting mode.) He also prefers full tones, which shows up on the display as 99 values but in reality Horton says it's more like 30 (I think that's what he says). I've tried these and it takes a lot of practice because the sounds are all over the place when you're swinging over trashy ground. I've tended to compromise and use max tones but with all the iron range (negative TIDs) and the top two most conductive bins notched off. I can easily switch to filtered all-metal to check iffy signals. What I really wonder about is whether I have a lemon. I've heard so many good things about the X-Terra 705. And yet it hasn't been an easy detector for me to use. I'm notching off the 46 bin. Do others have to do that to squelch the wraparound signals? I have a friend who owns a 705 and I'd like him to try mine out and tell me if it matches his. But unfortunately we don't live all that close and he and I are both busy with our "real" jobs which makes it difficult to find a common time and place for such a test. In the meantime I'm sitting tight and awaiting next spring's warm weather to get back to operating it.

Randy Horton does a better job than I can: Understanding Your X-Terra See p. 78, but it's mentioned elsewhere. You can search for 'wrap'. Well, thanks, but I'm not there yet. Kinda like when I was 19 wanting to be 21. Takes forever to make it through those last couple of years!

Even though you may have made up your mind (at least on some things, such as ruling out the F19) I think it's worth adding some of my experiences (opinions?) The above link has excellent pricing on a new Teknetics G2, which is AFAIK the same electronics & performance as the Gold Bug Pro. Steve has, in multiple places, indicated the minor differences between the F19 and the GBPro. (BTW, Teknetics version of F19 is G2+ -- yes, almost same name but with a plus-sign.) I have a Fisher Gold Bug pro with 5 coils (three factory, a 15 inch Nel Attack, and a 6 inch Coiltek prototype that never made it to production), a Whites TDI/SPP (almost same as TDI/SL) with 5 working coils plus a Garrett Infinium coil I'm trying to mod, and finally the Minelab X-terra with the stock coil (7.5 kHz) 8 inch round concentric plus Coiltek 'Digger' (2.5 kHz) round DD. My experience with these detectors, mostly coin hunting but some nugget hunting is far below what it needs to be in order to give strong advice. I will say that I like all of them. The TDI/SPP is super easy to set up and run, and does well in hot rock infested Arizona desert and Colorado mountains. The GBPro is (in my limited experience) very good at finding small metal bits (no native gold yet ) and does very nicely coin hunting. It only has three tones (actually two true tones plus silent) in discrimination mode so it's not as diverse in that (and many other ways) as the X-terra 705. But it's super lightweight and I don't miss the notching (which it doesn't have, but the F19, G2+, and X-terra have) because I'm digging everything above iron, anyway, and I mean that for old coin hunting as well as nugget hunting. I've put in about the same amount of time with the X-terra 705 as the GBPro (rough estimate 75 hours each), but mostly with the small Coiltek Digger since the sites I hunt are loaded with iron (mostly nails). I'm still getting to learn the wraparound from iron to silver.... OTOH, the GBPro TID doesn't always give the truest reading (some larger iron reads conductive -- i.e. in the coin region) and maybe every detector made today has some kind of TID issue. In my opinion, if saving money is important, check out used detectors on eBay where 50% of retail is typical and sometimes you can do better than that. (Of course there are exceptions for the newest and/or most popular models, where 60-75% of retail is more likely.) And the Teknetics T2 is very similar to the Fisher F75, except it apparently only works with DD coils (which, IMO, isn't a big loss, at least in my limited experience). Some people say being able to run concentrics IS a big deal and they probably know better than I do.... I've had very good luck (if you want to call it that) buying used detectors and coils. Sometimes there is warranty left on used detectors, too. Getting new detectors is fun and I've come close to buying used F75/T2 and also a used Whites VX3, but I took Steve's advice and decided to learn to better use the ones I have, for now. Besides, by the time I'm ready to get another there may be some new, revolutionary detector available and I'll want to put my money on that. Even if I go with tried-and-true, the used prices are very likely going to be lower than they are now. On top of that, winter is setting in and I'm not as fortunate as some of you to live where detecting is a year round opportunity. But I retire in 20 months.

If there's a 1 under that 2 (on the 1942 date of the dime), it's potentially worth more than the nugget. OK, not likely, but never hurts to give yourself all the options.

That was my thought as well. In the US we call it ground/grounding (attaching something conductively to the chasis) but I know elsewhere (e.g. Europe and apparently Australia) the term 'earth' is used. (Earth = Ground. Makes sense!) I've been working on one of my SPP coils. The inside of the coil's plastic housing is coated with a conductive paint and a wire from the cable is epoxied (with conductive epoxy) to the coating. Both halves of the housing are coated and attached. This serves as both an electrostatic shield (for preventing frictionally generated electric charge buildup&discharge -- think about walking across carpet on a dry winter day and touching a screw on a light switch -- zapp!) and also an electro-magnetic-interference (EMI) shield. I've had this issue with a 1970's detector I still own, and don't remember if it is inherent in that detector from the beginning or whether the problem developed over time (as yours=Jim's has), but probably the latter. In at least one of Charles Garrett's books he talks about things one should look out for when buying a detector, and the sensitivity to vegetation (leading to falsing) is one of them. So apparently cheaper detectors way back when were made by cutting corners and not properly grounding the coil housing. I don't know how easy it is to open the coil housing. I suspect some manufacturers seal their coils permanently that it can't be done. But if your coil housing can be opened (e.g. carefully breaking the seal with an Exacto or other sharp, thin knife) then you might just find a disconnected wire which can be reattached. Seems like there ought to be repair shops out there that can do this for you. Of course we live in a "don't fix it; throw it away" society -- not like back when there were radio&TV repair shops that could fix about any electric or electronic device. So maybe not....

Although not the show Tom tried out for (this one likely already in the works before that), it appears to have all the components: cameras following seasoned(?) prospectors/miners into dangerous locations to strike it rich: http://www.discovery.com/tv-shows/legend-of-croc-gold/ http://www.monstersandcritics.com/smallscreen/alaskan-miner-searches-for-gold-in-papua-new-guinea-on-new-series-legend-of-croc-gold/ First episode was two days ago. I don't think I'm ruining anyone's watching pleasure to point out a couple things about that one: 1) they have yet to find a speck of gold. 2) their visas only last 6 weeks! I think it's safe to say that far more gold is made in the entertainment world with these series than is actually found/recovered by the treasure hunters / prospectors / miners (and I mean any/all of the many such shows out there).

First off, I find it interesting how close this is in almost every way to the Deteknix units, right down to the way the transmitter is attached to the detector shaft. This Garrett (both transmitter and receiver) are a bit larger, likely due to its longer battery life (20+ hours compared to 5+ hours for the Deteknix). The operating time between recharging is the obvious big difference between the two. (We apparently don't know yet the cost difference....) I have zero experience with other wireless headphones besides the Deteknix. I'll say this much -- his comments about noticeable lag time for some wireless headphone systems do not apply the Deteknix. As fast as I can X over targets I notice no delay. Assuming the price is reasonable I'll likely get one of these when it comes out. I bought the Deteknix model which comes with on-ear headphones. (They also have the T/R + 1/4 inch female jack for the use-your-own-headphone crowd.) I'd like a system for my over-ear headphones which I find both more comfortable and better sound-blocking and now that Garrett is going to make them I'll probably go with theirs next. One thing I find a bit disappointing in this video is the use of (Lesche) long handled spades in public parks. It's different in the latter part of the video when they are in (private?) empty lots which are going to be bulldozed anyway. I know some who don't even use the small Lesche trowel for digging on public property but rather just use probes/screwdrivers. Even when used with extreme skill, the perception/image from the public is something that must be considered. I have a lot of respect for Garrett. It's safe to say they've played a very significant positive role over the years with the quality of their products, their widespread advertising, and other PR such as books and videos. The size of the metal detecting world is (IMO) significantly larger than it otherwise would have been without this company's presence. But with respect comes influence and the more public your image the more one needs to be aware of setting a good example. For all I know the municipal park where they were hunting is fine with spade digging, but many viewers of the video aren't going to be so discriminating and I wish they had not shown this part.

Once again I realize the real world is different than my myopic view of it. These subscribed sites apparently generate enough advertising revenue (that's the motivation, right?) that whatever it takes to get followers, that's what they are going to do. It would be nice if even 10% of those watching are actually seriously considering becoming dectorists themselves. I don't know the worldwide detector sales and doubt if the manufacturers are going to tell us, but for now it's keeping about a dozen companies in business. That says something.

say what? I must be watching the wrong Youtube.

That's a very impressive result (factor of 2 in depth), even though limited (one item, presumably under perfect = perpendicular orientation in air conditions, and one measurement by one person). It would be nice to see how other specimens perform. True native nuggets (as has been said on this site and elsewhere a gazillion times) will not respond like coins. Eddy currents set up most easily in round ring shapes followed (I think) by nice disc shapes. So how this improvement translates to nuggets is TBD, but promising. In the coin realm, US $1 gold (1.7 g), 3 cent silver (0.8 g), 5 cent silver ("half dime", ~1.3g), and 3 cent nickel (1.9 g) -- all from the 1800's, could also benefit from an increase in sensitivity such as this. I recall there were privately minted small denomination gold coins during the gold rush years as well. It would be nice if more data could be compiled. I already have the stock 5 inch plus a prototype Coiltek 6 inch for my Fisher Gold Bug Pro. Even though the Nel Sharp is quite reasonably priced I'd like to read more before committing another Benjie to my growing collection of coils.