Tortuga

On 3/26/2015 at 8:33 AM, Steve Herschbach said:

Going after trashy for those with the fortitude to slowly get it out of the way is a good strategy, provided of course that there is a decent chance gold is lurking. People with PI detectors tend to avoid trashy sites, yet mining camps were often built on the richest ground. You are in the right area for sure, just have to be persistent and keep at it. It took me years to find my first gold nugget with a detector, but once the first one happens, it is like a dam breaking loose. Many, many people report a similar experience. That first one is the hardest for all but the very few. Good luck!!

a few more tips....

Steve's Guide to Metal Detecting For Gold Nuggets

Same experience for me. Took me about two years to find my first one but they rolled in after that. A lot of it was just a morale and confidence booster. Once I discovered I really could find gold I just worked that much harder. Maybe harder than the two years prior. I wanted to find the next one, then the next one etc.

I'm a major MacIntosh user - Color me "stupid" with the directions posted, but the Manual Download procedure indicates just hooking up the Zed USB to my Mac and transfer the software update.....

What file is that? The downloaded "GPZ_7000_UPDATE_IMAGE_20151009.ml3"? That is hardly the referenced "Minelab(E:)" ---- That said, it is a 10.2 MB sized file . Can I just download that file onto a flash-memory drive, and plug that into the GPZ's USB?

I totally respect Steve's aid in providing this information on the update, please don't misunderstand - I'm just caught in this unreal world of Mac vs PC applications and the issues thereby presented.

IF there is another Mac user out there that has successfully done this download - please respond, I certainly would appreciate it.

iMac user here. Just upgraded mine today.

Downloaded the file from the Minelab website and dragged it onto the GPZ drive from my desktop. Piece of cake.

Did you pan that material?

Good idea!

Like the SDC, I think the "vented" coil cover on the GPZ has something to do with it being a detector you can use in the water. The cover isn't sealed on there with tape like the old ones. I think Minelab designed it to let water drain out of it.

I've since switched to the black coil cover cuz I wore my stock one out.

tortuga, i thought it was a wedge for a minors pick to hold the handle to the pick head, the curve is the thin side. I've had some old picks around as a kid and they had similar wedges, but you could also be right a dimple for the set screw in a plane blade could look like that, this would have been a curved gouge if it came from a plane.

Interesting. I'll have to take a pic of what I've got but it looks pretty close to yours. Found it a few years back detecting for relics in a pasture.

I like your summer wrap-up a lot better than mine and although a little embarrassed with my tiny gold, i did love every minute of the hunt. Lunk you are an inspiration and seeing how you magically pull the yellow stuff gives me hope that someday (next summer) i'll learn enough to find a little more, WTG.

some of my hard earned trash...

That flat thing at the bottom of your pic with the round dimple in the center. I found one of those before. Wasn't sure what is was, maybe a blade for a wood plane?

There's an area I hunt that's nothing but bedrock and the "interlocked" rocks you're talking about.

It's tough work but I've kind of gotten used to it. It's sorta fun now, like a jigsaw puzzle sometimes with gold nuggets in it.

It's a lot different than swinging on hillsides and just digging up soil and clay.

I know Lunk covered this last spring, but I want to reiterate. This morning I got the classic faint mew tone, repeatable in both directions. This is the kind of tone we live for, I knew it was gold because I was out of the trash zone and it was obviously not a surface target. I was running HY, Normal, smoothing off, gain 12. I decided to play with the settings a little. First I switched to HY, Difficult, same sensitivity. The target was barely audible and I doubt that if I was in regular prospecting mode it would have been sufficient to stop me. I already knew it was there, so I had too much advanced knowledge. Then I switched to General,Normal, same sensitivity. The target was still very clear. I toggled back and forth, clearly the Difficult setting faded the target. Low Smoothing had little effect, but I was in very quiet ground. My conclusion, at least for this quiet ground in Sunny Yuma, use Difficult as a last resort. The nugget was about 5 inches deep.

What's the default gain setting on the GPZ? That's one thing I haven't touched since owning it.

Interesting story about sticking with the boot scrape. I know there's a lot of boot scrapes I've left behind that I just couldn't wrap my head around and dismissed as hot ground.

I usually detect in Normal and Audio-Smoothing Off then if I hit something I can't tell is a metal target or hot ground I'll switch to Difficult. If the target disappears I'll usually move on. I've dug quite a few deep holes in some nasty thick clay that I think just had some bad hot rocks at the bottom of them because of the wide spectrum of the sound. After a little digging metal objects should eventually start putting off a pretty clean high-low or low-high tone.

However, the real question is whither or not I should be Auto-Tracking or not with my GPZ once I find a signal that's giving me some trouble.

Do you think after spending 5-10 minutes sweeping your coil over it and scraping a little dirt away here and there that eventually the GPZ will start tuning out the target, if it's faint and deep enough?

Sounds dubious to me, especially the doubling of finds part.

 

Unless I'm misunderstanding something, attaching 600 ohm headphones to a circuit designed for 4-8 ohms is going to make it quieter, might even actually need to get a booster to bring it back up to normal loudness, though maybe the SDC has robust audio control already, dunno since I don't have one. But electronics gurus please correct me if I'm wrong there...

 

Also, the amps in detectors aren't designed with nearly the frequency response that high dollar audio amps are made with, which is what those sorts of headphones are intended for. It's like hooking a $300 pair of headphones to a Walkman from 1984...except probably worse. Or trying to listen for frequencies on a 60 year old record that just aren't there to begin with.

 

Though I bet the sound deadening capabilities on a set of nice studio headphones are excellent, that is one positive that could make a difference.

 

Gladly change my opinion given new evidence to the contrary though.

Makes sense to me. If the source (detector) isn't requiring high-end studio headphones like a $10k McIntosh amplifier might then we should be fine just using the regular detector headphones that are on the market.

I don't see a big difference between the dirt that gets in your scuff cover and the dirt you're swinging your coil over on the ground. It's all dirt...

Unless you get a bunch of black sand in there maybe.

I've been curious about the actual audio output and speaker quality on metal detecting headphones as well.

I think most of the emphasis manufacturers place on their headphones is ruggedness and just make vague claims about the "faintest whispers from nuggets can be heard".

I'd like to know if anyone's done any research like you're asking about specific ohm ranges that are compatible with our metal detectors that output the best signal.

I mean it's not like we're trying to listen to rock music coming out of our Minelab's. We're listening to electronic tones the machine is spitting out based on what the electronics inside are trying to tell us.

I've had a pair of Sunray Pro Golds I've been using for a few years now that work fine and I've found some nice gold with. But I've been wondering if the $120 headphone "connection" I have with my $10k detector can be improved at all.

By the way Jimmy I don't know where you're located but I'm selling a used SDC 2300 if you're interested. Drop me a message if you'd like.

I like that nice 5.2 grammer. Looks like a little foot.

I didn't get anything.... 

Nice work, I love Arizona gold.

It's an hour away from where I live.

First Texas - Even we don't know how many we make or what they're for!

Garrett - We already made a flagship detector so quit asking for one.

Minelab - The most hated name in detecting!

Tesoro - Search for the past with detectors from the past.

White's - Anything happen while we were sleeping?

Holy crap that's funny! 

The Gaines Creek owner later sold it to Peter Hydlar who sold it at the Tucson Gem Show. I got to hold it during the time Pete had it for sale.

No kidding?? That's awesome. Pieter always has such nice gold at the show. Lots of nuggets he's found and ones he's acquired from collections. He has a beautiful 11 ounce(?) gold and quartz nugget from the Quijotoa Placers that's near and dear to my heart that I'd love to own one day. He usually has a big silver bar from the Atocha shipwreck for sale at the Gem Show too. I live about 10 minutes away from the hotels where they host the shows and I've been going every year since I caught gold, gem and meteorite fever (and even before that when I was a kid in elementary school and they'd drag us there for field trips).

Pretty neat stuff. The last issue of the GPAA Gold Prospectors magazine had a good article on jade.

Ivan I am not too sure about them ??

This Walco pick is the one I want Note the Curve and the size of the Blade and they have a piece of 38mm tubing that is between 4 to 5 inches log so it protects the handle in case you hit the handle on a rock, and the sides are flat, In OZ they are the industry standard and that steel tube is crushed to make it an Oval shape so the handle does not twist, Like in the picture below,

http://www.goldsearchaustralia.com/index.php/our-products/accessories/pick-lesche-tools-trowels-shovel/picks-2/large-walco-pick.html

That's the pick I've been using lately and that's the website I got mine from. The handle is plenty long, which I like. Good for digging deep GPZ holes. However not long after owning it I did tweak the metal pick head a little trying to pry a huge boulder in a wash. It just barely got twisted a little, no biggie.

It's a little thinner steel than an Apex pick, like I was using before, so you can't be too rough on it but for 90% of the stuff I dig it's fine.

Wow that's a big one...

Scratch the little shiny parts with a nail. If they break up and turn black its pyrite or chalcopyrite.

Some people have all the luck... 

I've been using one of the black covers for a few months now. Wore out my stock GPZ cover with a quickness here in Arizona banging around dry washes and sharp rocks. The stock one is made of soft, Tupperware-like plastic.

The black replacement cover (got mine from Rob) is A LOT thicker. Sorta like that Kydex material they make gun holsters out of. It's a little heavier than the stock one but I use a bungee with my GPZ do it's not really a big deal. I probably won't ever wear the black one out. Didn't notice any loss in depth, sensitivity etc.

Still bringing home lots of gold.

Well added a new pick to the collection, ya know how many picks I got in my truck........

Ivan's Wacko Pick

ivanwacko.jpg

Looks like a damn good pick.

Great post Steve, that really makes the Gold Modes undersandable and explains the different types of ground that each mode should be used in. However, some may be confused wondering what, then, do the Ground Types of the GPZ 7000 accomplish? I've found that the Gold Modes act as a sort of "fine tune " for each Ground Type; for example, when I'm hunting in the Normal Ground Type and High Yield Gold Mode and the ground is too hot for this combination, instead of simply going into the Difficult Ground Type I will first try General Gold Mode and if the ground is still too hot, Extra Deep. Extensive testing on undisturbed targets in a variety of ground types has revealed that more sensitivity is retained by this fine tuning method than by just choosing the Difficult Ground Type right off the bat.

This is how I use my GPZ as well. Each setting for me is just another way to "dumb down" the detector in tough soil.

In mild soil I use Audio Smoothing: Off, Normal Soil and High Yield.

If the ground gets hotter I turn Audio Smoothing: Low.

If it gets worse I switch to Difficult Soil and continue down the chain until things get quiet. Fortunately I don't have to switch settings much where I detect but maybe somewhere like Rich Hill with a little tougher ground mineralization might require me to "dumb down" my GPZ.

I haven't even touched the Sensitivity or Threshold settings on my GPZ yet. The stock settings seem to work fine for me.

That's some really interesting info.

Seems like Coiltec or NF could sell alternate coils for the SDC if they came with detailed instructions with pictures on how to install them and a little star head tool or whatever is needed to open the case. Naturally big bold letters would have to be printed on the first page of the instructions saying installing a new coil voids your warranty.

If I take the middle carbon fiber shaft out there is often a powdery substance on it where the clamp holds the shaft. I think it's dust from either the clamp or the shaft being ground down from the twisting. It slowly gets easier and easier for the twist to happen and I think that is why - a thousandth of a mm every week or so getting ground off and decreasing the diameter of the shaft. When I first got my detector it seemed like I was correcting the twist 1 or 2 times a day, now it's maybe every 10 minutes.

So, hopefully this post here can be used as reference that the problem existed at least for some of us basically out of the box. Because I have a feeling that eventually it'll get worn down enough that the shaft will not be held in at all, and it'll probably happen past my warranty phase as luck generally goes. So it's good to get it documented.

Looks like from that presentation that they've done most their expected sales of the 7000 in Australia and the US and now they are concentrating on Africa. The engineering costs were not too out of this world from their graphs, and considering you can build entire computers on palm sized boards for $20 now I don't think the materials costs are much of the $10k equation either. Sounds like your explanation is probably right Rick.

When I first got mine I didn't think the "shaft twist" was that bad either, just chalked it up to the overall "floppy" design of the coil the GPZ has now that Minelab got away from using plastic wing nuts you can tighten down. However like you said I think mine's gotten worse too. I've logged a lot of hours on mine since I got it and I'm frequently adjusting the length of the shaft for when I'm hiking in/out and detecting up/down slopes and stuff. I do like that you can adjust the shaft fast and easy like the SDC.

Is there a way to disassemble the shaft and wrap some tape around it to increase the diameter a little so the clamp can "grab" it better?