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Jim in Idaho

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About Jim in Idaho

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  • Birthday 12/21/1948

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  • Location:
    Blackfoot, Idaho
  • Interests:
    Prospecting, machining, equipment design/build, predator hunting, flyfishing
  • Gear Used:
    Whites GMT, TDI-SL, DFX. Homebuilt mineral jigs/with auto-feeder, for gems. Polaris 4 x4 ATV

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  1. Concentric Versus DD Coils On White's MXT

    John, the RNB packs for the GMT, DFX, MXT, etc. are 3-cell packs. max voltage is 12.6...perfectly safe in those models. RNB doesn't make a 4-cell pack in that configuration. To my knowledge, the only person making, and selling the 4-cell pack is Reidman. You defintely don't want to put a 4-cell pack in the aforementioned detectors, but it works terrific in the TDISL. Jim
  2. Using The GMT To Find Black Sand Paystreaks

    yes, and sadly, it's still too slow to change the numbers. Required several pumps over my samples to get the numbers to change....not good. This whole discussion makes me wonder why no mfg. has offered a simple machine to do nothing but track black sand concentrations? Maybe it's more complicated than it appears.
  3. Using The GMT To Find Black Sand Paystreaks

    Thanks, Steve...good read!
  4. Using The GMT To Find Black Sand Paystreaks

    I figured it was time to do some serious testing on this, Steve. I've seen tidbits here and there, but nothing very definitive. I'd read that you had to pump the coil to make it work. Nobody is going to spend more than few minutes doing that! Talk about arm-weary...LOL. There's a branch of the Snake not far away, that is now dry. River hasn't run there for thousands of years. I thought it might be a good place to look for black sand streaks, and collect some material to pan. I decided I needed to know just what the GMT could do for me in that regard. When I get some time on the dry channel, I'll be sure and post it. Jim
  5. I've been planning on some testing of the GMT's ability to find paystreaks of black sand. Finally went down near the Utah border and collected some sand to use. I was disappointed in how slow the GMT's indicator changed over the sand I used. Much too slow, unless you want to die of boredom before finding any. That's probably why so little is written about it. It only works in "autotrack", too. I tried various levels of V-Sat, Gain, etc., but nothing worked in a way I'd spend much effort doing. But, I DID find something that works.` I put the GB in Manual, and cranked the GB as POSITIVE as it goes (99). That way, it only responds to REALLY strong positive signals, and most negative signals. I turned the THRESHOLD all the way down. At those setting you hear very little ground noise, but still get a good response on the black sand. The gain can be adjusted to ignore the general levels of blacksand on a bar, but still respond to a higher concentration of it. The response is fast, so you can run the detector as if looking for gold. Of course, you won't hear any non-ferrous targets at these settings...they're strictly for finding concentrations of bs. The concentric coils had a definite advantage over the DD, but I would have no problem using the DD for this. I was using blends of pure magnetite,or at least ALL of the black sand I used could be picked up with a magnet, mixed with sand that had no magnetic iron in it. I used both a 1:5 ratio of bs to white sand, and a 1: 10 ratio. Both were detected at nearly 4". I didn't try any ratios below 1:10, but I'm sure a ratio of 1: 20 would be detected, but might be only at shallower depth, depending on where the gain was set, and that would depend on the level of bs in the general run of the bar being detected. Another thing on the mixes used....I used a teaspoon of magnetite in each mix. Put them in sandwich bags, and spread it into a thin layer. But, to be fair, the coils could always see the entire teaspoon of magnetite, as the test blend, even spread out, was smaller than the area of the coil. All of the sand used was smaller than #50. I tried using the "learn accept" function on the DFX, but could make nothing work on that for finding black sand. Tried several different programs and settings, with complete lack of success. Jim
  6. A Shoutout To Whites

    Many thanks, Steve! Jim
  7. A Shoutout To Whites

    Well do, John, assuming I can figure out how to do it. Maybe I'll just email you a couple. Jim
  8. A Shoutout To Whites

    LOL.. I'm afraid Noah would have canned my old backside, John. My new to me GM 3 is supposed to be here today. Really looking forward to that! Jim
  9. A Shoutout To Whites

    Yup, swamp, old like me...LOL. We should make a good pair. With the little 5.3 concentric I bought this spring, this GM 2 beats the GMT with the same coil by about 30% on my 1 grain bar. Of course, have to manually balance, but I don't mind that. Jim
  10. A Shoutout To Whites

    Bought a GM 2 a couple of weeks ago. $120. Nice-looking unit, but had a tough time getting it ground balanced. Finally figured out the Sensitivity (gain) pot was shot. Every time I touched it I got loud howls from the machine. The pot is soldered into the circuit board, so I needed that specific pot. Couldn't find one on the 'net, so called Whites, with the intention of buying one. tech said...no problem I'll put one in the mail. No charge! So I got it yesterday, and took things apart last night and got the new one installed. Took about 1 1/2 hours. had a tough time getting the old one out (5 pins). Then had to drill out the holes with a #59 drill to allow the new one to go in. The rest was easy. Now I've got a nice backup unit for the GMT, and for a buddy to use when I'm out and about. Whites never ceases to amaze me with their service. Jim
  11. 1.8v AA Battery?

    You can buy a 4 cell Li-ion pack, that includes a built-in balancer from a guy that goes by Reidman. Be aware that you will be at a higher voltage, when freshly charged, than the rating on the electrolytic capacitors in the power supply, which are only rated for 16 volts. The pack will supply about 16.8 volts when fully charged. I've used his pack for over a year with no problems. I don't have a link to Reidman....you'll have to do a search. Jim
  12. I have one you can buy call Mike @ 520-403-6459 and we can talk price.

  13. Yup...I agree with all of that. Jim.
  14. I think Reg has come around on this, now, John. but he doesn't know, from what he's told me, exactly whats going on either. This whole thing may be just an "unintended consequence" of something Whites changed when shifting to the SL version. Jim
  15. A Big Quartz Speci

    Man, that's great! I never find that gold like that! Jim