Whites tdi depth while prospecting for gold

[Jim in Idaho]

Yes

 

[vlad]

I just recently bought a whites TDI sl and wanted to take it out while prospecting. Any ideas of what size coil would work better than others, or should I just stick with the stock 12 or 7.5 coil ? Is this a good Pulse machine to use ? Thanks for reading my post

Jimmy Sierra TDI specialty coils (4x6, 6x10 and 8x14) take the machine to another level for locating gold and much better than the stock Whites loops. I believe they are monos too. They have not been made in
a while but are around and ground balance properly. The loops were made by Miner John/razorbackcoils as I recall. Check with Steve Herschbach @ detectorprospector and also try NASA Tom's site too.

To give the SL model all the performance of the Pro, and maybe even better, you want three mods. First is the 16v battery pack. Those are no longer being sold, so you have to make your own, or find somebody to make you one. I just finished my second, so I have a backup. Second mod is to remove capacitors C20 and C21, which are .47ufd, and replace with .22ufd caps. What that does is increase the allowable sweep speed on tiny nuggets. As sold the SL requires a really slow sweep speed to see the smallest nuggets. Sweep too fast, and you won't detect them. Sweep really slowly, and there they are.That's part of why the SL has such smooth threshold. By changing those caps, you get slightly more variance in the threshold, but a much larger range of sweep speeds without losing the sensitivity to small gold. The third mod is to remove capacitor C56. Also removing diodes D20, and D21, and installing a jumper across two of the three terminals on D21's location on the board.. These last mods also increase the sensitivity. For the squeamish...just removing C56, and leaving the diodes in, will help. Do all these and your SL:will be every bit as good as the PRO, with less weight, and a smoother threshold. One guy I know just pulled 44 cents at a depth of 24" from a beach in Florida. He was using an * X 14 coil. The Whites factory, on the new Special Edition TDI has done the third mod. They removed D20, D21, and C56, and put the jumper on D21's location. I've heard, but don't know for a fact, that all SL's made after 2015 have had the third mod done.Only way to know is to take a look at the circuit board.
Here's a video showing the effect of the second mod...swapping the sweep speed caps:SS mod effects
Jim

Who were the guys Reg Sniff recommended for some interesting mods (including doing some things without going into ground balance?)

 

[vlad]

I just recently bought a whites TDI sl and wanted to take it out while prospecting. Any ideas of what size coil would work better than others, or should I just stick with the stock 12 or 7.5 coil ? Is this a good Pulse machine to use ? Thanks for reading my post

Jimmy Sierra TDI coils (4x6, 6x10 and 8x14) work very well for locating small deep gold and much better than the stock Whites loops. I believe they are monos too. They have not been made in
a while but are around and ground balance properly. The loops were made by Miner John/razorbackcoils as I recall. Check with Steve Herschbach @ detectorprospector and also try NASA Tom's site too.
Dan Guyer at White's made the original TDI coils but he passed away many years ago. I recall a detector shop in Vegas that always had a good selection of loops for the Tdi also.
(You may see ads for something called the "ferrous hound" for iron i.d. It is i differential magnetometer that attaches to the rod above the loop; as long as the iron is BIG it works but will not
work on small iron like nails. Made in Oz for P.I.s and my friends out west that hunt gold say its a waste of money as does Jimmy Sierra & Mr Bill.)

 

[Jim in Idaho]

Who were the guys Reg Sniff recommended for some interesting mods (including doing some things without going into ground balance?)

As far as I know, none of those guys still do the mods, and haven't for several years.
Jim

 

[Michaeldoc2u]

Jimmy Sierra TDI specialty coils (4x6, 6x10 and 8x14) take the machine to another level for locating gold and much better than the stock Whites loops. I believe they are monos too. They have not been made in
a while but are around and ground balance properly. The loops were made by Miner John/razorbackcoils as I recall. Check with Steve Herschbach @ detectorprospector and also try NASA Tom's site too.

Who were the guys Reg Sniff recommended for some interesting mods (including doing some things without going into ground balance?)

Thanks, Waterdog!