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Jim in Idaho

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About Jim in Idaho

  • Rank
    Copper Contributor

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  • Gender
  • Location:
    Blackfoot, Idaho
  • Interests:
    Prospecting, machining, equipment design/build, predator hunting, flyfishing
  • Gear Used:
    Whites GM24K, GMT, TDI-SL, DFX. Homebuilt mineral jigs/with auto-feeder, for gems. Designer & inventor & operator of patented "Sweep Jig' (US10159988 B1), Polaris 4 x4 ATV

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  1. Welcome, Bill! I like your area. I was raised in SoCal, and we used to vacation up in your area. Lundy Lake, etc. That was 60+ years ago. Brings back some good memories. My older brother was telling me, a few months ago, that when he and dad hiked up to an upper lake in the Lundy Lake area, they met an old timer who showed them a bunch of gold he'd panned up there somewhere. He told them he could pan an ounce/day, easily, and that's all he needed to get by.:-) Jim
  2. The changes to the TDI SL were about increasing the sweep speed, without loss of sensitivity to small nuggets. That was accomplished by changing the aforementioned capacitor values. Here's what Reg posted on this mod. "The caps being removed are C20 &21, .47uf and will be replaced with .22uf. Use 50v Panasonic, or Rubicon Stacked Metal Film Polyester type." Credit to Reg Sniff The only other change was increasing the battery voltage to 16.8 volts. There is a small risk of trouble by doing that. The capacitors in the power supply are only rated for 16v. But I don't know anybody that has used the higher voltage that has had problems. I've been using the 16.8v pack for 2 years. It does make a substantial difference in depth and sensitivity. Jim
  3. I hadn't posted the patent number. So here it is for you guys that might want to take a look at the construction, and operational details. US10159988 B1 I should mention that building one of these, even for personal use, is forbidden under the new patent laws that went into effect in 2012. Jim
  4. Looks to me like the batteries have the controller built in. Or are they simply stating what should be done when charging/discharging? Jim
  5. NIce V's! First coin I ever found was an 1889 V. Found it while nugget hunting, using the GMT. Yours are in good condition. Jim
  6. I got 62.39 using this formula: (SG -2.65) x 19.3 / (19.3-2.65) x SG That result is 14.629/56.743, which gives .2578, or 25.78% gold, which equals 62.39 grams SG of the specimen is 3.408 Jim
  7. Yup...it's a good thing to know how to do, especially for a prospector. It was a good refresher for me on calculating the portion that's gold, too. Jim
  8. That's better, though I'm coming up with 88.34 grams of gold....LOL Jim
  9. All the formulas in the world won't help if the specific gravity of the gold/quartz specimen is lower than quartz. If you divide 242 by 171, you get 1.415, which is much lower than quartz. If it was 2.65, it would be 100% quartz, so being 1.415 means either the water weight, as stated, is incorrect, or there is a large portion of lightweight mineral, or air, inside. If it's a gold/quartz specimen it has to have a specific gravity higher than 2.65. Jim
  10. Yeah, as Walker said, must be a void, or large portion of very light rock within it. Maybe you should soak it in plain water overnight, and then do the water weight test again. If there is a void, and it fills with water, the water weight should be correct. If there is a void, and the water can get to it, you should see bubbles rising in the water. Jim
  11. Yup...I get a density of 1.415g/cu.cm. That's lower than pure quartz. Jim
  12. I wondered if I'd get a hard copy from the Patent Office, and today I got a nice 15 page booklet, in the mail, of the entire patent. Now I need to order a few more....LOL Jim
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