Effects Of Ground Balance On Target Depth?

[Jim in Idaho]

My tests showed the improvement on both a nickel, and a 1 grain gold bar. The improvement was much less with the Miner John 5 x 9 folded mono. The way I conducted the tests was specified by Reg Sniff, and I conducted them at his request. The tests were posted on Whites forum, and Findmall, if anybody is interested.

 The following tests on the 7.5DF I made a mistake, so should be ignored. I haven't had time to do them over.

Jim

[Hobo]

what is a one grain gold bar? My TDI wouldn't detect a one grain piece of gold.

[LipCa]

I'd like to see the mold for a one grain bar....grin

Maybe a one gram bar?

[Steve Herschbach]

Jim, again, are we talking about a modded unit? Or a factory stock TDI SL?

What you appear to be saying is that on your detector disengaging the ground balance cuts performance across the board in air tests. What I have trying to do on this thread is illustrate why under very low mineral conditions people may want to experiment with shutting the ground balance off or reducing its aggressiveness to get better performance. There would appear to be no option for this on the unit you have, and the option to disengage ground balance may as well in itself be removed. It serves no function on your detector except to decrease performance.

That being the case beach hunters would be wise to stick with the original TDI and TDI Pro because with ground balance off they are one of the best straight PI options available for beach detecting short of the Eric Foster Deepstar itself.

[Jim in Idaho]

No Steve, no mods. All the tests show is that having the GB on increases depth. There's a slight increase by turning it to max, but even at the lowest setting simply turning it on makes a significant depth difference.

I just finished the new tests on the 7.5DF. Not much difference due to battery voltage, and turing the Gb on made little difference on the 1 grain gold bar. But it made a +15% difference on the nickel.

Battery Voltage tests Whites TDI SL 7.5"DF coil

Freq: centered: Pulse Delay: 10: Gain: Max

 

!6.2V

 

                      Nickel                             1 grain Gold Bar

GB OFF:        10.75"                                      2.75"

GB ON    Switch in "all"

  Min.              12.75"                                      2.75"

  Max.              13.25"                                     3.00"

 

GB On      Switch set in "low"

                        N/C                                           N/C

 

 

12.3v             Nickel                              1 grain Gold Bar

GB OFF           11.0"                                       2.75"

GB ON

  Min.                12.75"                                     2.75"

  Max.                13.0"                                       2.75"

[Jim in Idaho]

1 hour ago, LipCa said:

I'd like to see the mold for a one grain bar....grin

Maybe a one gram bar?

Not 1 gram...1 grain. I can send you a pic if you need one..LOL The bar is about 3/16" long x 3/32" wide. It's in a plastic card, so I can't measure the thickness.

jim

[Steve Herschbach]

Hi Jim,

Thanks for that. Again, I am puzzled why this information directly contradicts the TDI SL Owner's Manual. My own recollections of what I remember using the TDI SL I will just consider out of date. I will leave the whole issue of TDI SL and ground balance on or off to better minds than mine except to note that according to what we are hearing from you and John, that there is no advantage to be gained with a TDI SL by turning the ground balance off. The goal always on this forum is in just trying to help people get better performance out of any detector they own regardless of brand or model. I appreciate you guys helping achieve that.

[green]

Hi Jim

Do you have some hot dirt to verify the detector does cancel ground? If I did my math right your bar would be about .012 inches thick.

[Jim in Idaho]

12 minutes ago, green said:

Hi Jim

Do you have some hot dirt to verify the detector does cancel ground? If I did my math right your bar would be about .012 inches thick.

The GB works fine. I've never had a problem getting it to balance anywhere I've used it.

Jim

[Jim in Idaho]

50 minutes ago, Steve Herschbach said:

Hi Jim,

Thanks for that. Again, I am puzzled why this information directly contradicts the TDI SL Owner's Manual. My own recollections of what I remember using the TDI SL I will just consider out of date. I will leave the whole issue of TDI SL and ground balance on or off to better minds than mine except to note that according to what we are hearing from you and John, that there is no advantage to be gained with a TDI SL by turning the ground balance off. The goal always on this forum is in just trying to help people get better performance out of any detector they own regardless of brand or model. I appreciate you guys helping achieve that.

Steve, I can't explain it either. When John first mentioned that to me, maybe a year ago, I thought he'd been smoking old kangaroo hides. Everything I'd read had said that GB off gives the best depth. I needed mine on for the places I detected, so never thought about it much. I hadn't communicated with John for several months prior to the tests, and he had no idea I was doing them. I was as surprised as anybody with the results.....kept redoing them thinking I'd made a mistake. But Reg told me, after I gave him the results, that he thought Whites had changed something in the GB circuit on the SL. I've never heard from Whites on the subject, though I've heard from them on the voltage comparisons. Maybe they've figured something out on GB? Who knows? All I can do is post my results. I'm not trying to convince anybody of anything.

Jim