Testing White's Nugget "Shooter" Coil: The Arizona Challenge
by Ron Long
www.AZ-Gold.com

  All you folks with White's Goldmasters don't have to borrow your buddies' Gold Bug 2's with 6-inch coils anymore to work tight spots and beep dinks in hot ground. White's new 6-inch "Shooter" Mini DD coil adds a whole new dimension to nuggetshooting with the GM series.

  After spending nearly 30 grueling hours over six days testing the new coil at three challenging Arizona goldfields in 110° heat, if I had to sum up my reaction to the Mini DD in one word, that word would be "Confidence." Sure, it's got a minor flaw or two, but its performance makes those flaws very tolerable.

  I had received the new White's 6" Mini DD coil from Jimmy Sierra, White's Electronics Western Distributor, earlier in the week, but couldn't get out the first time 'til Saturday AM.

I mounted the coil on my well worn White's GMT, taking extra care to protect the cable from flopping around, as suggested by Steve Herschbach of Alaska Mining & Diving. I used two Velcro strips to bind the cable firmly to the lower rod, allowing only one turn all the way up to the middle rod connector. Between the middle and the detector control housing, I wound the cable tightly and secured it in a couple of spots with more Velcro.

  In my first day's trial, I met up with Bill Southern (Nuggetshooter.com) and a couple of his friends at a well-hammered, highly mineralized patch near Rich Hill. Many nugget shooters who are regulars on the AZ Prospectors Forum, most using Mine lab SD's, GP Extremes or White's Goldmasters with 13" GoldMax coils, have hit the patch hard. I figured it would be ideal to test a small coil there because the only thing left would be dinky targets hidden in challenging ground.

  I began my hunt just after sun up down low in an area of tailing piles and well raked red dirt, a spot I know has produced lots of little nuggets over the years. The GMT mineralization screen read 71. First, I set my Gain to 7, my VSAT to 10, my threshold to barely audible and the tracking to automatic. As soon as I started swinging I knew I was going to like this coil. I quickly realized I was able to slow down my VSAT and nudge up the gain to 7.5, even though I usually can't do so with either my standard GMT DD coil nor my Sierra 13" GoldMax coil because of the high mineralization of the Rich Hill area.

  These new settings produced audio responses that are very different from the crisper sounds I am used to. The slower SAT speed blurred the edges of the target response, making it more of a "Wwooppp" than a "Zip."

  I wasn't sure that I liked the difference, so I decided to do a quick air test with the little three-grain plastic encapsulated nugget I carry in my hip pocket. I was quite surprised to see that the slower SAT speed, though a bit irritating in the highly mineralized ground, gave me another two-plus inches in depth, at least in the air. I was actually picking up the target sound at six to seven inches. True, the sound was but a small break in the threshold, but it was one I would dig, especially since the GMT also registered a "good target" reading of 25.

  Within the first minute of swinging on the red raked dirt, I got a good, very loud target. The GMT meter read 25, normally an indication of non-ferrous material. I scraped the dirt back and after digging only about two inches I had the target out of the hole. Quickly separating red dirt in my black plastic treasure scoop, I saw the first of what was to be many small lead and birdshot bits, this one the size found in .22 caliber snakeshot..

  I was excited to find a small target so quickly right in the middle of many fresh dig holes (most nicely filled in, thank you). The area included numerous old trenches, the sides of which had been well raked over the years. The tailing piles between the trenches looked promising because they were largely unclassified. Rich red dirt, schisty bedrock shavings and a jumble of rounded cobbles and angular hillside float were all mixed together in a way that suggested the original miners had rushed through the overburden to reach the rich finds right on the bedrock. And everywhere a patchwork of recent detectorist digs proved the popularity of the spot among enthusiastic nugget shooters.

  I picked a likely looking area of rakings, and gridded an 8' x 10' patch. To my surprise, nearly every couple of feet produced a target. They ranged from surface to approximately six inches deep, all rusty trash, hobnails, bullets or birdshot. I was amazed that there were so many targets in such a hammered area, but, as Bill pointed out later, it seems most people dig a half dozen trashy targets and give up. At first I determined I was going to take advantage of everyone else's impatience, but, after about 30 targets, I decided to move on myself. The sensitive new coil was finding targets so small that, even with the iron ID of the GMT, bits of lead and aluminum were so numerous as to make the digging tiresome.

  I spent the rest of that first day hunting a nearby patch area that had far less trash, but ended up my hunt with nothing to show but a spoon-full of very tiny birdshot, assorted larger caliber lead and a bunch of boot tacks. The Mini DD had proved to be able to handle the ground pretty well, but I was having to adjust my attitude about the false signals I was getting whenever I attempted to "snake-charm" back into the thick brush. Anything that touched the coil wire gave off a target-like zip.

Day Two--Little San Domingo Goldfields, where they invented "hot rocks"

Although I was somewhat pleased with the performance of the Mini DD at Rich Hill on my first day with it, I was concerned that, in really hot or highly mineralized ground, the noisy reactions I was getting in tight spots would be intolerable. So, early the next morning I headed out to Little San Domingo (LSD) goldfields, where both GPAA and Roadrunners have many claims. It's also a spot I'm sure they invented hot rocks, which are often suspended in caliche, and radically mineralized bedrock. The nuggets at LSD are widely dispersed, with most found on ridges and hill sides rather than in the washes.

  The area is a favorite of mine and one I have spent hundreds of hours hunting. It's the site of my first Arizona nugget, found after spending 25 years mining and dredging in far Northern California on the Scott, Salmon and Klamath Rivers.

  By 6:30 AM I had strapped on my snake gaitors and hydration system backpack, containing 100 ounces of cold water, together with a few salty snacks, extra AA batteries and other nuggetshooting accessories for a morning in the AZ furnace. I carried my "100 Nugget Rake," for attacking old tailing piles, my Walco pick, my trusty and well worn black plastic treasure scoop and my .22 Magnum Davis Derringer loaded with snake shot.

  Soon after starting out, I realized the Mini DD coil was reacting very differently than it had at Rich Hill. On auto tracking and slow VSAT, gain at 7.5 the ground was just too hot. Everything I touched gave false target sounds. Every touch of a bush sounded like a mushy target and the auto tracking seemed to be muting targets. I changed my settings to manual ground balance, fast VSAT (10), and gain to 7. Immediately, the machine smoothed out and, although I was getting some false target noise when I bumped into bushes or rocks, the sound was definitely not a "target." It was just a noise. And a tolerable noise, at that.

  I recalled having seen other nugget hunters using small coils having wrapped the strain relief tightly to eliminate coil falsing. So I wrapped a wide piece of Velcro very tightly around the Mini DD strain relief where the wire entered the coil. This only slightly limited my ability to move the coil up and down to adjust to different terrain angles, but it almost totally eliminated the falsing. Not completely, but enough to allow me to cautiously snake charm into the brush. That made me a happy guy.

  I knew the particular ridge I was hunting like the back of my hand. It is a rather large patch with no particular nugget concentration. Sometimes you find nuggets in one of the hundreds of tailing or header piles, most dating back to the '30's or earlier. Other times you find nuggets encased a few inches down in the hardened caliche, the calcium magnesium salts deposited in layers over eons of evaporation of ancient seas or lakes.

  Generally, gold nuggets found in the area are in or around the old workings, so that's where I concentrated my efforts. I started hitting the ubiquitous tiny birdshot, interspersed with the donkey and horseshoe metal tobacco bag icons so common in this area of depression era mining.

  I've hunted the patch area very hard, particularly during the first six months of 2002. Nevertheless, I was finding targets I'd missed with my GMT-GoldMax combo, SD2100 and Gold Bug 2. I fiddled with my gain setting, fluctuating between 6.5 and 8.0, and found that the gain, most of all, was the key to handling the rapidly changing mineralization of the patch. The manual ground balance of the GMT, which is as close to an automatic balance as you can get, allowed me a baseline to work the gain setting.

  Approaching an area where I'd found several small nuggets ranging from a couple of grains to a pennyweight, I set the gain at 7.5, VSAT set back down to 4, manual ground balance and bare threshold. The mineralization readout stayed steady at 72. Carefully gridding one of the old tailings areas where I'd found several dinkys, I was surprised not to hear a target. I decided to test once again, using my little three grain test nugget. With my current settings, the target was loud and strong at five to six inches, air test. Then I buried the nugget three inches down in the mineralized ground. Surprise! I could barely hear it, and the mineralization was masking the sound almost completely. I adjusted the VSAT setting to 10, and that made a major difference. Although quite, the signal was strong, and the chirp of the mineralization was all but gone.

  I retraced my steps, and half way through the grid I got a good signal. The meter bounced between 15 and 30, so I knew I had a good non-ferrous bit. Sure enough, at about 2-1/2 inches, I popped up a nice little 2-grain nugget, my first with the Mini DD.

  I continued hunting for another hour, but the southeast facing hillside was becoming unbearably hot, without so much as a breeze to keep me cool. Although I found a few more bits of birdshot, there were no nuggets to add to my poke.

  I felt the new coil had performed quite well in a difficult mineral area, but I decided to give it the ultimate test in hot ground---The Vulture-Red Basin goldfields, southwest of Wickenburg.

Chasing Vulture Dinks in a Mineralized Inferno

  I picked the Vulture-Red Basin goldfields for the final test because it has a lot of very small, crystaline gold, some right on stringers or small veins. It also has extremely noisy, hot ground and quantities of both cold and hot rocks. I also selected the area because there are extensive patches in which I've put hundreds of hours with a Gold Bug 2 fitted with at 6" coil, as well as with a GMT and standard DD coil.. Those two combinations have produced well over a hundred nuggets, ranging from sub-grain to half ounce.

  I really wanted to push the Mini DD to see just how much I could get out of the gain in this ferocious ground. I set the ground balance to manual, because I was stalking the elusive "Vulture Dinks" which generally are so small that the GMT auto tracking will cancel them out. I cranked the gain to exactly eight, turned the VSAT to ten and lowered the threshold to the point it was just a vague electrical crackle, more felt than actually heard. The mineralization number ranged from 74 to 76.

  As I started slowly sweeping the ground, I was getting slight false signals whenever I'd bump a rock or bush, but they weren't too loud and sounded nothing like the solid ZIP the GMT gives over a good target. The highly mineralized ground was making a little crackle, but I quickly became used to it and basically didn't hear it.

  There are numerous old, very flat tailing piles in the area I was hunting and they often produce for me. I pulled out my "100 Nugget Rake" and started digging down a couple of inches into the pile nearest my truck. Right away I got a solid target and the GMT ferrous graph bounced between five and 15. I halved the dirt in my treasure scoop a few times and, sure enough, the dinkiest, smallest nugget I've ever found with a metal detector. Barely the size of a pin-head, the little bit was down nearly two inches. The Mini DD had been about an inch over the surface.

  This raised my curiousity. I wondered how my old reliable Gold Bug 2 with its six inch coil would fare in comparison. I placed the nugglet back down in the hole and covered it up, trying to duplicate the challenge the Mini DD had met. I got my GB2 out of the truck, all ready set up with the six inch coil. I swung the coil over the target, a couple of inches above the dirt. Nothing. I then lowered the coil to the surface and swung. Again, no zip. Finally, I started scrubbing the ground down a little at a time. After about a half inch of dirt had been moved aside, I got my first slight hit. Another quick nudge down just a hair more, I got a good target sound, flipped the discriminator up and got the satisfying Gold Bug 2 confirmation that I had gold under the coil.

  I hunted the area a while longer and found a couple more little crystaline nuggets, ranging from sub-grain to 1.5 grain. The thing that was most interesting was how loud the sounds of the tiny nuggets were. Even though the Mini DD was constantly making noises as I bumped and scraped the ground rocks and bushes, the sound of a real target was so distinctive and definite, that it became easy to ignore the other sounds.

Going for the bigger nuggets

  Having proved the new coil to myself in the little dink field, I decided to go to an area where I'd found larger pieces. A few hundred yards away, but still exhibiting the dark red earth and mishmash of hot and cold rocks, the patch was above some extensive header and tailing piles. Despite extensive raking, I'd never found any gold in the piles, but had found several half to one penneyweight nuggets on the slight rise above the piles area. The patch, however, is very small, only 10 by 30 feet, and I have gridded it with my SD2100, GMT, both GoldMax and standard DD coils, as well as the Gold Bug 2, both standard ten inch and six inch coils.

  Checking to make sure my GMT-Mini DD was set up the same as earlier, I started slowly working the patch. I went but six or eight feet and got a target, but the ferrous graph said it was iron trash, well over 75. I rubbed my rake-head over the area with the super magnet attached, and sure enough, a tiny bit of rusty metal. Moving on, I got immediately a very, very loud solid signal which I figured was another rusty bit. But the ferrous graph said "fifty," then dropped down to fifteen as I continued to swing. I changed the angle of my swing ninety degrees and the graph dropped down to one little bar, about two on the scale. I gave a quick pull with my rake across the surface, but the target was still in the ground. Raking again, I went down an inch, then two inches. On my fourth pull, the target was out of the hole. Halving the material in my scoop, I quickly saw the target. It was a beautiful, flat nugget with good character and approximately five grains in weight. While it was much bigger than the other dinks I'd found, the sound from the GMT was so loud I was sure it was much, much bigger.

  All told, I spent four days, hunting the Vulture in 105 - 110 heat. At times, the Mini DD coil was too hot to touch, but it didn't have much apparent effect on the operation. Once I figured out to wrap the strain relief to prevent falsing, I finally learned to live with the back ground noise from bumping and scraping the coil. All in all, it was a great pleasure to hunt with. It's distinctive "good target" sound is so much louder and more definite than the other sounds, it is also fun to hunt with. When the GMT says, "target," it says it with authority. The only limitation I found with the coil is that tight cracks or holes in highly mineralized bedrock are not easily hunted. It does, in that instance, produce too much noise that sounds very much like a target.

  Despite this single limitation, the White's Mini DD coil is a winner in my book. It rounds out the Goldmaster coil arsenal and will serve very well for prospecting very hot ground, dry washer piles and mine tailing piles. If you're a GM swinger, ya' gotta have one!

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