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Jim in Idaho

TDI SL Mods And Tests

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I did both of Reg Sniff's suggested mods to my 2013 model TDI SL. I also use a 16v battery pack. I was testing it yesterday on pieces of nickel. I buried a 1 gram piece at 6", and a 1.84 gram piece at 10". The TDI saw both with the 7.5"DF coil, and the 8 x6 NF Sadie coil. The 12"DF coil could only see the 1 grammer....same for the Super Pulse 14" 350. The signal on the 1.84 grammer was faint, but repeatable. I'd definitely have dug it in the field. The signal on the 1 grammer was strong with both the Sadie, and the 7.5DF. Could have easily been deeper.
Jim

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Jim, would you be so kind as to repeat those tests with the standard 12 volt battery pack? I am sure many of us would appreciate knowing how the two compare. Thanks!

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No problem, Jim, but I'm leaving tomorrow for a prospecting trip, and may not get to it until I get back.

Jim

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Had to walk Heidi anyway, so grabbed the TDI and did the tests.

The 7.5DF lost the deep target, Some, but not a lot of difference on the shallow target. The 12DF couldn't see the deep target anyway, but could still see the shallow target. Now a couple of things to keep in mind. One is that when I did the initial battery tests a couple of years ago, It seemed to me that the smaller coils didn't gain much by the higher voltage...a little, but not much. Second is that where you see the benefit of all these mods is at the fringes. You're stretching the limits so to speak. So, if you have a strong target at 16v, you're still going to have a decent target at 12v. But, a weak target at 16v may be gone at 12v. The shallow target was not at the fringe with the 16v pack, but the deep target was. Shallow target could have been an inch or more deeper.  Even the 14" 350 Super Pulse coil could see it. My pack was at 11.8v just now.

One thing that surprised me the other day was that in previous tests, using the 1 grain gold bar, in air tests, the 12DF was the most sensitive. But in the in-the-ground tests, the 7.5DF, and the Sadie were both better. I haven't come to a conclusion about that. I didn't have time to do a battery comparison on the in-the-ground gold bar. When I tried that with the 16v, I could get a repeatable signal at 2 1/2" with the Sadie, and 7.5DF. Couldn't see it with the 12DF at that depth.

Jim

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Always glad to see your results, Jim.

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