GB_Amateur

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GB_Amateur last won the day on July 10 2016

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About GB_Amateur

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    Copper Member
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  • Gender
    Male
  • Location:
    Southern Indiana
  • Interests:
    Any and all metal detecting; geology of gold
  • Gear Used:
    Fisher Gold Bug Pro, White's TDI/SPP, Minelab X-Terra 705

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  1. Been a couple months since the last post on this thread. In the meantime the weather has gone from unfriendly to detecting in my home region (Midwest) to springlike temps (but dry!) giving many of us several days to hunt. Also, I've since read Tom D.'s exhaustive feedback to Makro/Nokta regarding the new Impact. I can't speak for others, but there is a lot of info there that, IMO, applies to other detectors, not just the Impact, Racer2, and Fisher F75 which he uses for comparison. If you haven't seen it, keep in mind it's not a quick read as it took me several sittings to reach the end. Here's the link to the forum thread: Back to the wraparound issue, I got a chance to try the Minelab 5 inch round DD 18.75 kHz coil this weekend (11 hours total) on the X-Terra 705 in my two standard locations (both municipal parks) where I've hunted a lot in the past 7 months with the Fisher Gold Bug Pro (5 inch round and 7x11 in^2, both DD's) and the 705 with its stock (for coins/jewelry) 8.5 inch round concentric and also the Coiltek 'Digger' 6 inch round DD 3 kHz loop. Just for review, in both locations I've found old coins (Indian Head pennies) and 19th century military buttons. One was previously an industrial site while the other was a farm with outbuildings prior to becoming muni parks. In particular the former farmyard is loaded with iron bits, especially nails but also fencing, implement parts, steel cans, etc. This one has driven me bonkers with wraparound from -8 (most ferrous) to 48 (highest conductor) and even down to 46 (large format dollar) and 44 (half dollar). Most of my previous searching was done with the Coiltek 6 inch, but I do recall wraparound with the ML concentric as well. To my surprise and relief, running with the ML 5 inch @18.75 kHz, even in the worst iron infested spots, resulted in very little wraparound! There was just a bit but it was not only easy to recognize, but so infrequent that I wasn't being confused/overwhelmed. Iron sounded iron and conductive sounded conductive. We can all speculate on the reasons for the huge difference, but given that non-ferrous and ferrous lead to different performance at different frequencies, with associated compression and expansion of response TID regions, this is likely a big factor. I ran at the same gains (23-25) and (for the most part) in the same ground balance phase settings (31-32) via auto ground balance (not tracking). For most of the time I was able to run in coin&jewelry "all metal" (no notching) and with "99" tone setting. Auto frequency shift (to minimize EMI) is almost always +1 in these two locations, independent of coil choice. In no way am I able to compare max depth (still building my backyard test garden) but first impressions are that there isn't an obvious/significant difference in that part of the performance. Next time out (won't be this weekend as there is still some typical February weather forecast) I'll try the stock 7.5 kHz 8.5 in. round concentric again and see if it is in-between in terms of wraparound issues. I haven't had that one on except for a couple backyard tests (backyard is pretty iron free, by comparison) since I first got the detector in August. That will add some more data to my growing notebook.
  2. I read through that thread -- good info and thanks for that. Is this you youtube video you refer to? Interesting that someone else said changing the channel (small frequency shift to minimize EMI) actually reduced wraparound. Another thing I need to try when it gets warmer.
  3. Yep. Some 19th Century US coins as well. Zinc pennies aren't typically difficult to recover, since they are usually in the top few inches. I hate 'em but I'm not about to miss something good to avoid them.
  4. My experience learning the subtleties of the nomenclature very much parallels yours. Another qualification is "positive" hot rock" and "negative hot rock" -- something Steve details above. It is unfortunate that misnomers, which come early in a field of study, become common practice/usage, but it happens all the time, particularly in pure science. It's annoying but, in my experience, nearly impossible to swim against the current. For example, 'gram' is a unit of mass, not weight. But almost everyone (including many/most scientists) say "...this specimen weighs XX grams...". I have a couple large hot rocks (one looks very much like yours!) I found at a GPAA claim between Briceburg and Yosemite in CA, along the Merced River. The description you give of how the TRX pinpointer reacts is exactly what my Garrett Carrot did -- if you can 'surround' the tip of the pinpointer by as much of the rock as possible it will beep. Break off a piece and the check it with the pinpointer -- silence. Both rocks give a 40 ID on my Fisher Gold Bug, which is considered the dividing line between ferrous and non-ferrous, although (see Steve's review of the GB) small nuggets can show up on the iron side of this boundary, so as is always the case, size and shape of the target can have a significant affect on the ID. My White's TDI/SPP ignores these rocks completely, meaning the response pulse arrives less than 10 microseconds after the pulse was transmitted. So the detector is acting just as it was designed to do -- ignore the magnetic non-conductors and the very low conducting materials. (Note: some hot rocks have resulted in signals on the SPP -- uncommon but not impossible -- so in those cases there is enough conductivity to lead to a longer than 10 us response pulse.) Another thing I found with both rocks is that I can get a very low resistance reading (few ohms) probing with a multimeter. This can be interpreted as "highly conductive". One of them has a very dark, matte finish, consistent with graphite, but the other one (that looks like yours) is more deceptive, even showing some quartz veins. Both have specific gravities around 2.7 -- quite typical of many rocks but well below most meteorites (darn...). Although I haven't ruled out the possibility that there is (valuable?) metal buried inside, it seems like a very distant longshot. If you decide to go to the effort (and expense?) of sawing yours open I'd be curious to see a picture of what you find. Another option may be to break it apart but I don't have the equipment to do that with mine. Although I haven't done so yet, I'm sure my non-metal-detecting wife would appreciate a donation to her garden. Brownie points await.
  5. Cors (aftermarket independent coil manufacturer) has made coils which are advertised as operating at all three frequencies. I couldn't find anything regarding this at their website, which either means I'm not good at finding web info or they've discontinued making them (temporarily or permanently). At least one Ebay seller has them -- here's an example ad (they were making them in various configurations): http://www.ebay.com/itm/CORS-Scout-12-5-x8-5-DD-Search-Coil-Minelab-X-Terra-All-Frequencies-/291652981609?hash=item43e7df5369 These cost 1.5 to 2x what you pay for a single frequency Cors coil of the same general design (size and config) but if they really do work at all three frequencies then it's about a factor of 1/2 what you'd pay for three coils. Real time multifrequency detetectors such as the Whites V3I and VX3 and Minelab 3030 give you more options (and don't require a coil change) but at considerably higher initial prices. I already have two 3 kHz DD coils (Coiltek 6 inch and 15 inch, both DD) for my X-Terra 705 plus the stock coin & jewelry 7.5kHz 9 inch concentric. Later this week I'll be receiving an 18.75 kHz 6 inch round DD Minelab coil, but I'll likely be on my way to the Southwest US by then so won't have a chance to try it out until I get back mid-February (weather permitting ). It will be especially enlightening to compare the performance of the two 6 inch DD's because the 'only' thing significantly different is the operating frequency. Personally, changing coils hasn't been an issue for me because I usually am hunting with one purpose (e.g. coins or nuggets) and typically you know which coil you want to use, at least which frequency. Also I often am within close proximity to my vehicle in case I want to do a change. I understand that backpacking your swappable coils is more hassle than just walking over to your vehicle.
  6. I can't read the date on the Indian/Buff nickel, but it kinda looks like 1918/17 (D). That would beat most nuggets that get pictured here.
  7. Of the various things I've attempted in my life, Rudyard Kiplings poem 'If' has applied to every one of them. My favorite line in that poem (of which every line is powerful): If you can meet with triumph and disaster, and treat those two imposters just the same
  8. Agree. But actually my concern was a price increase in the near future from the market $190 (compared to the market $290 that Coiltek retailers were charging). As has been mentioned here before, price reflects more on what the sellers feel the market will bear than the manufacturing+marketing costs. Maybe it's $50 cost for them.... Just bought a used Coiltek, so I should be good-to-go. Thanks for the helpful responses.
  9. Thanks, Bryan. This is exactly the kind of response I was hoping to get here. Show me a site that even comes close in cooperation/assistance among members! What makes me a bit concerned is this: I can understand why Coiltek&Minelab would go into a cooperative agreement here. Coiltek apparently has a superior product and Minelab has the marketing and sales network. What I don't understand (and thus makes me suspicious) is why the price went down so drastically. One thing I've noticed about coils (not necessarily tied to one manufacturer) is how the prices fluctuate. And it's not just the downward direction. It's Minelab's business and decision to set the prices where they feel they will make the most profit in the short run and long term, and we've seen this in the past; it's no secret. But are they going to continue to sell a coil they don't build (and thus share the profit) at 2/3 of what Coiltek was asking, or is this just a hidden introductory offer?
  10. A couple things to consider given your choice: 1) Used ones sell frequently on Ebay for $1500 and occasionally less. One advantage to buying used is that often you can pick one with the exact coil you want, instead of the factory/box stock coil. 2) Steve wrote an article in the January 2016 ICMJ Prospecting and Mining Journal titled "Detector Prospecting Accessories" and the second paragraph begins "One of the first things to consider but that many people ignore is ergonomics." He goes on to describe methods of reducing the arm/elbow/wrist/hand stress. In fact on the first page (page 10) is a picture of Steve loaded down with a Garrett ATX. I don't know for sure, but think the ATX is the heaviest treasure detector on the market. (I qualify 'treasure' to set it apart from military land mine detectors.) 3) To continue on the ergonomics topic, although on the webpage Steve references above he indicates the ATX control box is not hip-mountable, I seem to recall somewhere links/references to article(s) where others have done so (without Garrett's blessing, of course...). However, balance is also a key component so if/when you remove the control box you still need to alleviate the heavy searchcoil torquing the shaft. Where there's a will there's a way. If you're in water you gain the advantage of (upward) buoyant force, but on land, 6.9 lb is nothing to take lightly (another pun :) so I recommend finding a solution equal to or similar to those mentioned above.
  11. I'm considering buying (yet) another coil for my ML X-terra 705 -- 15 inch DD operating at 3kHz. Often Minelab and Coiltek offer complementary (different size/frequency/winding) coils, but in some cases, as what I'm considering, they offer coils that appear to be quite similar. Given that the Coiltek costs about 50% more, I'm wondering if I should apply the "you get what you pay for" standard advice or save $100 for a future coil purchase.
  12. It's surprising to me how appropriate this book still is, and just imagine the reaction of a young person who thinks everything worth reading is on the internet (or Facebook or Twitter -- gag) and been written in the last few weeks. I can't find a date on mine but it highlights the Whites 5900 DI and 6000 DI detectors, so I'm thinking > 20 years old. Thanks for this post, Mike. I like learning by reading, and when it's cold and dark outside (like now) it's the best option I have. Those other books were just added to my wishlist.
  13. If the word gets around (and it might), I predict a boom in detector sales in the US. I'd be thrilled with a random 5% of your finds for a year. I agree with the first part. However, for me, any silver (coin or jewelry) fits in the 'quality' category. I have a couple questions: 1) How many hours (or if easier, days) did you spend finding all this stuff. (Sorry if you said that already and I missed it -- I may have been too busy looking at all the pretty pictures.) 2) Based upon the number of mintmarked 1909-1915 Wheaties, I'm wondering if you found some kind of timewarp zone (for lack of a better term). I.e. were you in a place(s) that was preferentially visited during that time period, such as an old church/park that was closed in the late teens. Do you have a count of the number of non-mintmarked Wheaties that you found last year that were minted in that decade?
  14. 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.
  15. 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).