jasong

I posted quite a bit here on this forum about Normal vs Difficult last year, made a vid to demonstrate it on an undug nugget too. mn90403, if you have 3 GPZ's at hand do a quick test - 1 operator, 1 target and 3 different machines with the same settings, report back. Switch to manual if you are tracking targets out. With very tiny targets it often comes down to coil placement - height and placement of the TX windings over the target makes a big difference for the tiny or deep faint stuff and can be the difference in hearing and not hearing something.

its an old amp I bought used, the sticker fell off but want to say its a rooster booster or something like that. it was priced right and I needed something right away because my second stock battery failed mid detecting. im giving some serious thought to one of those reed's now though but not sure I can justify it since my detecting time is cut waaaay back for the foreseeable future. doc must be using some really bad batteries because I've only had one aftermarket battery fail and only after a couple years of use. which is coincidentally about how long the $400 Minelab batteries lasted me too before I swore to never spend that much on one ever again lol. the stock batteries use sanyo cells for what it's worth, I took them apart. oh also I use the AZO box cover, I had to sew in some Velcro straps inside to hold the battery because they are longer than the pocket.

It makes the gears turn... My initial thought was similar to your, but about dredging and some kind of passive venturi system to vaccum stuff up - air is forced into an intake as the vehicle moves and causes suction on a downward facing nozzle which discharges into a container in the pickup bed - just like a suction nozzle or jet on a dredge. A road dredge! Totally passive and just powered by the moving air as you drive. Just gather platinum as you drive to and from work, not bad... Ok now, which state will be the first to ban road dredging??? If I ever find time away from work now to start building stuff I'll give it a try for fun. That little bead came just from the 150 grams he put in the crucible too. Then you also have the silver and other PGM's left over that can be refined and sold too. Yeah, not much gold here in Wyoming and its all in a few small places that are heavily claimed so gotta expand horizons haha.

I use $15 LiPo 5000 mAh 7.4v Turnigy packs from China and solder on a connector. I have 7 of them so I always have spares. They last about 5-6 hours which can be a bit short depending how much hiking in you have to do. I have a couple 1500 mAh mini's that I got for $6 and one always stays in my cell pocket in my camelback with my cell booster pack, sometimes I just use those when I want really lightweight without the bungee and just hiking in to someplace to explore for a few hours. This is just me but the stock battery is like the "brick" version of 80's cellphones compared to a modern cellphone, I really wish they'd update that part of the GPX line to smaller and lighter LiPo and wireless, we shouldn't need to carry around a battery on a backpack in 2016 IMO. That Reed's amp looks pretty interesting, might have to try one of those if I don't build something myself.

Ok, not gold or prospecting technically, but this kid has some real creative ideas. Remember the "gold from home depot sandbags" idea that hit the forums a few years ago? Well similarly, turns out you can also get platinum from the roads. He goes through a pretty simple fire assay demonstration too for any who wonder how it works. An interesting channel for those who enjoy vids - he's also reopening up his grandpas old hard rock mine, doing single jacking by hand, making his own charges, etc I find it all pretty interesting and entertaining to follow along with.

I agree with all these. I'm curious to see what some of the other manufacturers who are working on new PI machines come up with, but it sure seems like the room to grow in the PI arena is getting slim and the future for the Z and it's derivatives is bright. Also agree with Norvic, cordless all the way. I personally don't ever want to use another cord again and the thing I really miss about my Z the most is the WM10 (well that and what would have been the ability to use the 19" coil now that I waited a year for in vain argh...). Some disagree but I thought the sound quality was better on the wireless module then some of the aftermarket boosters with a speaker that had a cord and that was one thing they got totally right. *Actually come to think of it, the best immediete improvement to the 4500/5000 I could think of is to offer a new model with the wireless capability built in (and a lightweight LiPo battery attached to the unit)- I am about due to replace my 10 year old 4500 soon, bring it on!!

Good point Dave, that would be awesome, wouldn't need high resolution for that either. Pay part of it off by renting your time out to drywashers and find all the best structural traps and buried boulders for them! Or know where to shovel off a foot or two in big nugget patch areas yourself and redetect. I wonder how fast/slow you have to swing though and how much ground you can cover? Or how deep the GPR goes? Don't some of the cart mounted units go down to 10ft or deeper or am I thinking of something else? Would it be useful for looking for big lunker boulder sized meteorites? The ones that are 3+ft deep and out of metal detection range but where there is nothing else that size underground in the top 10ft or so of a dry clay lakebed and thus you can assume it might be worth digging and checking out? Or are those meteorites totally weathered away to nothing before they get that deep?

I usually run my 4500 in manual except in cases where the ground changes every few feet and I don't have patience to stay in manual its quicker for me to just flip to auto and slow down the swing and let the tracker work so I can pay more attention to everything else and not my growing concern about wether my green button will last out this trip. Or where there is a lot of buried burned brush it's quicker for me to run in auto than wear my arm out in manual every 3 ft. I started running my Z in manual more once I got to Arizona. But honestly, when I'm out swinging with hours between nuggets and just looking for new places (which is most of the time), I just popped it into auto and didn't care if I missed a minute peep here or there that got tracked out. The Z tracker tracks a lot faster than the X tracker IMO, and locks more accurately. I'm a pretty lazy detectorist compared to a lot of guys out there though. I hate (and actively avoid) digging trash, I hate sweating the small stuff (nugget crumbs). I just like maximizing the ground I cover so I can find more patches and those are the only places I really spend time thinking about things like manual vs automatic gb. Just what works for me and my short attention span personally.

Steve, it was something I wrote in the coil advice request thread. Regarding US detector companies - here is another bit of personal experience I had. I grew up thinking White's was the only real detector company, its all I'd see in the parks, my dad had one at home. I got obsessed with detecting 15 years ago and I discovered White's was just across the interstate from where I was going to school - coincidentally I was studying pulsed power and EM field modelling through something very much like a metal detector coil (a solenoid). I asked if I could intern (for free), they said they didn't accept interns. Despite being a stone's throw from 2 universities. After graduating I asked who I could submit a resume to and they told me they weren't hiring and not accepting resumes. They never availed themselves of the open research partnerships the electrical engineering and physics departments offer to local businesses (including Intel and HP, both projects I attended conferences on personally). Maybe this has changed now, I don't know. This was 15 years ago. But I haven't seen much new come out since then from Sweet Home worth talking about. That's just my opinion persoanlly though, I saw how many views the MX Sport thread had. I look at ML's videos and work force and I see a lot of younger faces, I have to assume they are at least taking advantage of the domestic workforce their universities are training. Those guys end up learning from and growing up to be the Bruce Candy's of the future in Australia. In the US they end up being righands. It's not just US detector companies, it's a US philosophy in general with many different industries, and I'm speaking first hand as a guy who has never been able to get hired in a field he was actually trained in and loves. Literally the only places interested in hiring US native electrical engineers, physicists, etc are oilfield and mining industries and we end up with a bunch of guys throwing chain or strapping pipe that should be designing metal detectors instead. If you don't have friends or family working at these sorts of companies you'll never get a job at them no matter what. And the products show that and while it's not the only reason Minelab dominates the market, I think it's a part of it. No offense intended to the companies, just my experience. *But I do want to say thanks to the White's field tester who I met 15 years ago in a park and who gave me a free modified pinpointer and some advice on where (not to) go as I was still learning. Forgot his name but that was hella nice and I still remember even if I forgot about White's as a company.

Just to be clear though: the point I was making was not about a slightly larger coil hitting nuggets over a slightly smaller coil. As I said, the GPZ hit all but 3 nuggets equal or deeper than the GPX w/17x13 even with the coil size difference, I was clear to point that out. My point is that there is an anomaly here on certain types of gold between the 2 machines. We know the GPZ hears stuff the GPX just can't hear. And I have seen the GPZ struggles a bit on certain types of gold that the GPX hits just as hard as any other similar weight nugget. And it's not just the GPX comparison, disregarding my GPX results entirely - these nuggets are hitting 10-20% shallower on the GPZ compared to other nuggets of similar weight on the very same GPZ. But only those 3 nuggets. It's the gold, not the coils. It's an anomaly, and is remarkable to me at least as a field detectorist. In the sense that it's worthy of remarking and attention. And I believe it should be remarkable to engineers who look for ways to improve their product and who can't possibly test every type of target in every type of condition themselves.

Fred, I wasn't using both detectors on the same ground in-situ, I was just doing lots of experiments re-burying nuggets. The only place I've crosschecked in-situ is in Nevada but these nuggets all came from Arizona. I test like crazy anytime I use a new detector or go to new ground so I don't waste weeks of time missing gold while I learn the area and my 4500 is the closest thing to a trustworthy baseline that I have since I've run it basically in every type of US ground. Just a bit of background. The first nugget always struck me as an oddball because it was such a weak signal in the ground and thus I thought it should have been deeper, and I was also convinced it was trash when I dug it so I wanted to experiment with it. IIRC it was only about 14-15" down and kinda weak when I found it, way too shallow for a 3/4 oz'er. My 4500 was hitting it at 18" no prob reburied and no combo of settings could get the GPZ to squeek over it at that depth. I actually got it down to about 19-20" with the 4500 by cranking the gain and taking away most of the stabilization. That test caused me to test all my finds weekly thereafter to see how common it was and I found the other two. I'll go back and recover the same ground with the GPX someday just out of curiosity but its going to be a while before I get out of Wyoming again as I'm changing gears and have left the full time prospecting thing for now. All three nuggets gave warbly wire-type signals. One was like a wad of chewing gum with a couple thicker wire type protrusions but otherwise a real dense and pure chunk of gold, the others were spongy-ish/irregular with solid "stealth-fighter" type edges which were pyrite casts and lots of goethite or hematite inclusions. It's been a while so I'm not sure I'm remembering all the numbers correctly, but I gave a pretty thorough report to Minelab back when I found the first one. Just to be clear though, all the other nuggets I tested were at least equal or better on the GPZ (I didn't test anything under 1/4oz though, so it's interesting for me to read PhaseTech's posts too). I'd still use one over my GPX if it didn't cost so much and have such an unstable resale value. But I'm pretty happy and comfortable with the 4500 w/17x13 too.

I had the same results with 3 large nuggets. The first was a 3/4 oz chunk and I was hitting it about 3-4 inches deeper with my GPX + 17x13 Evo no matter what setting combo I used on my GPZ. And I run with a ton of stabilization on my GPX too so it was like running in High smoothing. So it's not just small nuggets. I didn't feel like incurring the wrath of the public by mentioning it though (I remember a few guys in Oz being almost run off forums early on for saying things like this) so I reported it directly to Minelab instead and gave an open invitation for them to come test it themselves (this was like 4 or 5 months ago now), which they can verify. In the following weeks I found 2 more nuggets, both over 1/2 oz, that peformed similarly - about 10-15% less depth on the GPZ no matter what I tried. I'm thinking I probably missed more last winter too for the same reason. Some people want to murder me for saying it (ok, overexageration, but still, it feels like it), but there are definitely holes in what the GPZ will hit deeper than a GPX with the right coils. Just like there are definitely some types of gold the GPX misses that the GPZ sings on no matter what coil. I'm just hoping it'll go less noticed in a thread about GPX's haha, because it should be said. Anyways, a good reason to always be testing things. That 17x13 hit on those nuggets noticeably and repeatably harder than the the 17x11 did which is another reason its become my favorite coil. Harder than would account for just the slight increase in size. I'm sure the Elites are great too, but I don't like rounds for general use hunting, just my personal preference though because I hunt a lot of places I need to get into tighter spaces and the ellipticals are easier to pinpoint with IMO especially for in situ nuggets in deep holes.

I haven't looked at new coil lineups for months so no idea on the 14x9 Evo, this thread was the first I heard of one. I use an older fiberglass 14x7 still (also have a 14x9NFA) and I use them almost entirely for rocky washes. For all around coils I feel that 14" is too small, but that's just my personal preference and the areas I hunt. The 17x11 was perfect for me but I like the 17x13 even better because its more sensitive, deeper, and I don't mind the weight since I spent a lot of hours swinging a GPZ. I have a rigid schedule when I detect and I try never to fall below 2 grams/day average so covering more ground is more important to me then finding every last nugget. But for someone else a 14x9 might be perfect.

That 17x13 Evo is the best all around coil I've ever used on a GPX. Between a 14x7, 17x13, and a 20" RM, they leave almost nothing for a GPZ to clean up except crumbs (in my patches in Arizona at least), which VLF's take care of more effectively anyways. Killer combo. If they have a 14x9 Evo out now, then even better! 14x9's are already more effective then the 11" stock RM's, I've tested it quite a bit, so a new gen is better still.

Hey Condor, did you do any tests on your black material? After further analysis of my own, which are similar to yours, I think they must be the black crystalline form of limonite or geothite and the crystalline form is just more resistant to acid so I didn't see a fizz. Mine streak more similar to Goethite. I think the brown stuff on your nugget is too, so it seems like a likely guess that's what the black crystalline stuff is as well. Might be a pseudomorph of something like pyrite originally (look for empty casts with a loupe). Gives you something to look for when prospecting for the source vein anyways if it checks out.

That's a good question Fred...wonder if one of the detector engineers here might comment on it? Because that sure would save some weight if it was possible. I'm going to take a guess that it has to do with the LR time constant and a quick current decay for sampling? Higher resistivity means longer decay for equivalent inductance coils. I wonder if they'll offer to package the 19" with the GPZ instead of the 14" as an option? If they do that and decrease the price again I'd buy another one.

I occasionally find nuggets with a blackish material too in Arizona. The closest for mine was some sort of manganese oxide like psilomelane or pyrolusite, but I don't think that's it because none of mine react with HCl, do yours? I almost think some of mine might just be hornblende now or something, really not sure but might be some starting guesses for your mineral anyways. A good place to get some ideas to start is to look at mindat and find what sorts of associated minerals are in the mines in the areas you prospect and then do various tests (streak, hardness, acid, etc) to narrow the possibilities down. Watching with curiosity...

Wow what a small world! I'm pretty sure that rig photo was taken in the hills just south of Wamsutter, WY where I lived and worked for a year on it's big brothers (Nabors 101&102) as a directional driller and I've "driven" it. It's even bigger than it looks - these rigs "walk", we drilled 20+ well pads with them. The ironic thing is they really are pinpointers, we could generally get within 5-10ft accurate wellbore placement at 18,000ft depth. I use a Lesche too.

The problem I have with them is that all the piles I know with heavy sulfide mineralization also lack large nuggety gold. So it can be difficult because the gold size requires something like a GB2 but these machines also hit on the sulfides like they are a nice mellow gold target. Difficulty can be further compounded when they are copper sulfides, for me at least, because chalcopyrite looks a lot more like gold than just about any other mineral out there, and when you are eyeballing teeny tiny stuff all day, hitting hundreds of these chunks of ore, its easy to get it confused and frustrated. I love detecting NV ore piles because often they are just white quartz and a little hematite so the gold is easy to ID right away.

I hope someone tests this against an 18" Elite and puts it on vid. I'd do it but I sold my 7. Be interesting to see if its a bit less sensitive to the salt or if it's more sensitive. That was the biggest weak point on this machine IMO. Larger coils are always less sensitive to hot ground and hot rocks, but I don't know if that applies to salt/conductivity the same way.

Nice, thanks! Great detector collection too.

Thanks, it's a Hermit Pick, Roughwater. I think it's a 34" handle but I can't remember exactly, I've broken and made a couple new ones since I bought it originally with a shorter handle and I like the long handle much better. I think more people ask about the pick I'm using than the gold I find. Not sure where you are located but they are pretty common in Arizona, quite a few shops stock them (or used to at least?).

Paul, have you tried giving it 12v? Near as I can tell the original battery was 12v but it's hard to determine since they are all long gone (one is a mercury cell for instance). That's cool you have some, I couldn't find any reference to the T-30 existing at all other than this one (literally the only pic online is of this actual machine), all the other stuff online was T-25 or T-20 or something. Any idea what year its from? The Fisher Labs phone # in the manual is only 5 digits long!

How about a couple decades earlier still? This is the new toy I just bought, it's a Fisher T-30 and I think it's from the 1960's and its probably my favorite detector I own now, seriously this thing looks straight out of an old sci-fi movie and I love it. Never seen another one like it and I'm wondering if it's one of the last ones in existance? Only reference on the internet to it is this one I bought. Funny thing about metal detectors, the antiques are dirt cheap even if they are rare! I haven't got it running because it takes some weird obsolete batteries but when I get time this summer I'm going to build a voltage converter for it and give it a good run in the park, maybe a nugget patch for a bit of humor too if I ever get out again. I don't think it was ever used more than once or twice and then put away.

Interesting thanks Goldbrick. I haven't been too up on the latest VLF models, didn't know that about the Deus, going to do some research on it tonight!