Reno Chris

Sometimes stubbornness is just another side of persistence, and being persistent and sticking with your prospecting efforts is what makes for a good prospector. is that ground mild enough for sharp? I am a big fan of sharp, but the ground needs to be pretty mild to use it.

Maybe when I get there it will change your luck - of course it might be a change for the worse!

Jim - You know that man made objects like coins are pretty uniform, but nuggets are all over the map and not uniform at all. Not all 0,1 gram nuggets are created equal. Detection depths are a complex mix of size, orientation, porosity, surrounding rocks, etc. I've seen pennyweight "nuggets" that a GPX 5000 would have a tough time with in air at 1 inch, and other pennyweight pieces that would overload a 5000 across a one inch air gap - it depends on the nature of the nugget. So I am uncomfortable with any simple statements that such and such a detector will detect nuggets of a certain size at a certain depth. Reality is way more complex than that. At any specific area, I feel pretty confident that on nuggets less than a gram, the SDC going to out perform the GPX 5000 and anything else except a high frequency VLF in low mineral ground (and even then its pretty close). On larger, deeper stuff the 5000 will outperform. The place I got my nuggets is one where the gold is porous and sharp edged. If you look real close a my gold, you will see a couple are actually small specimens - more quartz than gold by volume. This is the type of stuff PI detectors generally have trouble with - and I knew this. Over they years, I've gotten a lot of larger pieces there, but with my GP Extreme, I got very few less than a pennyweight. I remember digging a 0.4 ouncer that was only 6 inches deep. It was a weak signal and I was shocked to pull out such a large nugget at so shallow a depth with such a poor signal, but that's what this place is like. Then with the GPX 5000 and its greater sensitivity, I got a bunch of nuggets in the half gram to pennyweight sized range. Now I am collecting stuff of a gram down to about 0.1 grams at this place with the SDC. For large stuff deep, I will be using my 5000. For small stuff shallow I will use the SDC. In some places with super mild soils where nearly all the gold is tiny, like less than a grain, I will use a high frequency VLF. The SDC will displace a lot of applications I formerly used a high frequency VLF for, but not for all. Having seen a bunch of the silver specimens you post, I think the SDC would out perform a 5000 on most of them because of the finely crystalline nature of the silver.

In the last few weeks, I've had a chance to try out Minelab's new SDC 2300 in the hills of California. I've had excellent luck with it so far - 8 nuggets the first day out, 6 nuggets the second. I did up a blog post with more detail for Minelab's Treasure Talk blog. See: http://www.minelab.c...-s-new-sdc-2300 Minelab has a long history of introducing new, cutting edge PI technology, and the SDC 2300 definitely continues that tradition. Its very sensitive to small targets, waterproof to 10 ft., amazingly resistant to coil falsing on grass and rocks, rugged, compact and easy to use. Between the small gold sensitivity and the waterproof feature, this detector will be accomplishing things no pulse detector could do before. I plan to be using quite a bit the rest of this year. No question that a number of GPX owners will be wanting an SDC, and I am sure many of you will be interested in taking a closer look at this new detector, and I'd be happy to answer any questions.

7000 ft in the Sierra means Pines and scrub growth. You will still find nuggets, but in many places the pine needle blanket together with the other organic materials on the surface means the nuggets are generally deeper. You can still detect gold, but you lose effective depth because of the pine needles and growth.

This little spec of gold was found in the field with a detector - the ground there is rather mild. There were other bits that were larger near it, so when I heard the detector make a slight sound, I felt there was a good chance it was gold and after fishing around a bit, this little flake is what was sounding off on the detector. The coin next to it is 24.26 mm in diameter.

I got one with a VLF (Gold Bug 2) last summer that ran 0.006grams. That is the correct number of zeros.

When I first heard of the SDC 2300, I thought the same - why would an owner of a GPX buy one? In the same way, why would the owner of an SDC buy a GPX? After having learned more, I feel differently. There is good reason for a GPX owner who wants to get the very highest level of performance to buy a SDC, because it will do things the GPX cannot. It will find gold the GPX with a small coil cannot. There will be a lot more info coming out shortly, and I will have more detailed comments probably later next week. Its tough to wait for info, but its coming soon -

Very cool.

So a couple weeks ago I was out detecting with my GPX 5000 and all was going well. Steve Herschbach and I were hunting a spot where there are several patches in a comparatively small area a few hundred yards up to a quarter mile apart. At the last place of the day, I took out my GPX and turned it on, and it sounded weird (the 5000 goes through a specific set of tones on boot up and I know what is normal). I looked at the display screen and it was off - it looked the same as when the detector is off. It was making some faint sounds and I waived some metal objects past the coil and it did make a weak sound as the metal went by - but it was obviously malfunctioning and with the screen off, I could not adjust the sound upward even if I wanted. I tried a second power cord and that made no difference. I tried another coil - also no change. So I sent the unit into minelab for repair. They rebooted the unit to all the factory presets and it worked fine. Apparently this happens sometimes that the computer gets itself set to some weird setting and it wont run right unless reset to the presets. Turning on and off is effectively a partial re-boot, while retoring factory pre-sets is a full and total reboot. Sometimes that is what it takes. So, the moral of this story is......... if you find that your Minelab GPX 4000 to 5000 model seems broken, try a different power cord, try another coil (both these I already knew), but also try rebooting to all the factory preset settings. Here is the procedure from the GPX 5000 manual: To restore all Factory Preset settings: 1.Turn the detector off. 2. .Press the On/Off switch down and hold until the Reset Defaults menu appears (approximately. 5–6 seconds). 3. Turn Function Select to the right to select All Settings (as shown on the diagram). 4. Turn Setting left or right to restore all Factory Presets.The detector will restore Factory Presets and re-start. Just thought this falls into the category of stuff worth knowing if you own a GPX detector.

I should do well in the rivers - just a lot of trash there. On the other hand, concentrations of lead bullets and fishing weights will be the same places where gold will tend to concentrate.

Should be quite the adventure, and should be something to show most days. We will have three guys working when I am there and you will have two before I arrive, so each day will have more targets dug than if just one guy was working - more chances for gold finding. Right now I am leaning toward using my Fisher T2, but may do the GB Pro - they are so light, I may bring both with one to use as a back up. I will also bring my Whites TRX pinpointer - the faster the target is out of the hole, the sooner you are on to the next one. Most trash, bullets and nuggets of any size will be no problem to the pinpointer, though smaller stuff may be tougher.

Congrats to you, Steve.

The discriminator is not perfectly accurate, and distance from the coil to the target wildly affects discrimination. Last summer I got a very faint sound at an old gold mine. It discriminated out on my GB2 as hot rock or iron. It could have been a spot of mineralized ground and there were some in that area. I decided that there was a decent chance it was gold because of the exact spot it was in (my intuition based on experience). I dug down about 4 inches and the discrimination broke up a little, but sounded a lot better. I got down about 7 inches and it screamed and discriminated as clearly not ferrous. At 8 inches out popped 2 nuggets, one 2 dwt (a 1/10th of an ounce) and a second at one dwt (1/20th of an ounce). I was glad I trusted my intuition rather than reject the initial faint target sound that gave zero response on discrimination.

For more detail, Carl Moreland has book that he has written.

Hey Steve - lets have a photo or two of the gold you found with the ATX (cleaned of dirt and purdy of course). Congrats!

Hey Carl - I second Steve's comment that it is good to see you post here, and I want to wish you the very best of luck in your new position. You will be working with some very fine folks.

Hi Reg - It's an interesting line of discussion. I was not at the Greaterville meeting you mentioned, but have had long discussions about this with John B. He took pounds of gold off the mine dump that yielded the bulk of invisible gold that John used to show around. I have a sample of it in my collection. I am curious of the PI detector you mentioned but did not name. I have no doubt of the accuracy of your statements, but am curious about the name and maker of the detector. I am not sure which it was. Can you tell us? Of course when John used to do this, it was back in the days of the SD detectors which were notorious for inability to detect small and wiry gold (John's invisible gold is wiry). The later GP and GPX Minelabs have made incremental improvements but still have difficulties with the smallest and most wiry gold. As John B sometimes jokes, when they finally get the Minelabs perfected, it will be a Goldmaster (John's VLF of choice for prospecting). It one of those jokes that is funny because it does have a certain element of truth. I suspect the new ML detector will represent another incremental improvement in the ability of the ML detectors to see small and wiry gold, but we shall see exactly what it is when it comes out. Its good to see you posting, I hope you are doing well.

In looking at the volcanic fields of the southern Cascades north of the Sierra, there are many smaller volcanoes and some really big ones. I figure when the Sierra was buried by volcanic rocks, the situation was similar, many small sources and some big ones. Raise the price of gold to $2000+ and you'll get your funding!

The problem is that its hard to do lightweight and waterproof at the same time. Both the Garrett ATX and the up and coming SDC 2300 are based on military spec boxes, which make these machines hard and durable, but the military isn't as focused on lightweight.

And as you note, that's why the delay is needed. It is just that delay that has hindered PI detectors from seeing the smallest and most wiry gold. There is a brief momentary spike in voltage that occurs and that happens during the delay period. The weakest of signals from small targets are lost during this time - that's why the delay hinders the recovery of the smallest targets. Sometime a short while back Minelab published and patented a new method of dealing with the Faraday spike which will allow detectors using this technology to have a significantly shorter pulse delay. How short - don't ask me, I don't know, and don't ask me how they do it, I have a vague idea. But I think this is exactly what the MPF is - the same kind of general multi-period pulse length employed by previous GPX detectors, but done fast, meaning a shorter delay and capability to detect smaller gold. I think there is good reason for optimism.

I respect those guys, but have to say, I totally disagree with a lot of their conclusions, especially concerning the source of the volcanic ash flows that clogged the streams. Many of the mud flow formations that cap the top of the tertiary Rivers (like the Merten formation) have blocks of rock 1 to 5 feet in diameter. No, I dont think those rocks flew 200+ miles to land there from Caulderas in central Nevada.The trajectory of a rock flying that kind of distance would darn near put it in orbit, and the impact would have shattered them to bits. No, sorry, I will side with the old timers on this one. We have a chain of volcanoes north of the Sierra and the to the north, the Sierra disappears underneath those volcanics. The chain, known as the Cascades is the effect of the Juan Del Fuca plate sliding under the North American continent. The differential melting of the rocks is what formed the great batholith that is the core of the Sierra. The Cascades are known to erupt with violent burial of the areas around them for miles. Not hundreds of miles, but maybe 10 to 20 or more (remember Mt. St. Helens in the early 1980s?). Mt St. Helens buried the area around it with ash and rock flows that look exactly like what buried the Sierra. 20 million years ago the Cascades extended much farther south, and much more of the Juan Del Fuca plate still had not yet slid under the North American plate. The most southerly of the Cascade Volcanoes - Sutter Buttes - is no longer active and in a few hundred thousand years, it will be fully erroded away. The ones further south are already eroded away. Though he did not have the plate tectonics portion of the explanation, Lindgren had it right.

With gold prices as low as they are, and regulatory requirements what they are, a property needs to hold some real commercial sized potential, but I think 3 million ounces, while a mighty fine goal, is very wishful thinking. Interest at this moment is at a low ebb, mostly because of low gold prices. But you can get a company interested in deposits smaller than a million ounces - it just needs to have potential.

You'll have to come up this way again one of these days and I will show you some. At least your 3000 wont handle them without a DD coil. Even with the DD, it can be pretty marginal.

Apparently not enough bling to draw attention these days in Vegas.