F-75 Test Garden

[Jackalope]

Ground has warmed up out back, so I thought I would begin a test garden. Have a Lesche Ground Shark with a 3" wide curved blade 12" long, so a minimum amount of soil was disturbed.

Buried clad quarters at 8", 11" and 12". F-75 was set up JE, Disc. 0, Sens 99, 4H. GB was 80 (both Fastgrab and manual) and fe3o4 was .1. Smooth and silent.

Quarter at 8" had loud sharp high tone and VDI lock. Quarter at 11" had repeatable high tone (scrubbing the ground) with VDI jumping. Quarter at 12" was detectable with solid iron tone and VDI mostly on #14.

Didn't try Motion All Metal but I suspect it might hit a quarter a bit deeper than 12".

Makes me wonder how many of those deep (11" +) iron tone targets that I passed up may have been good. Until further notice; all iron tones pinpointing deeper than 11" and pinpointing as smaller items WILL be dug.

Ron

 

[jim tn]

n/t

 

[HumblePie]

Ron...with fairly high mineralization, those depth results are just excellent..especially for just disturbed soil. I'm wondering just how much deeper you'll find targets at in undisturbed soil. My soil here..north of Toronto..has even higher mineralization; my XLT will typically find and identify silver quarters down to about 7 inches, although there have been a few deeper exceptions in very dark topsoil (probably due to slightly less iron mineralization, and
enhanced "metallurgical effect" due to increased naturally occurring organic acids..keeping in mind that silver coins are reactive, especially since they're alloyed with copper). But, for freshly buried coins, 5 inches with solid signal, bouncy ID on a silver quarter. At six inches..broken, unrepeating signal, period.That's jewellery mode with sensitivity at 72 out of a max of 80. I intend to try my test patch again when the two feet of snow go, with iron disc only, and in true all metal mode...should make some positive difference.

It's generally understood that target ID is less reliable as depth increases and even less reliable with increased iron mineralization. Moisture content, and external electrical interference also play a role. Unless the signal at depth can be easily identified as being not a coin/jewellery target, ie. sizable iron trash by sizing it up using the all metal mode..pinpoint is fine, I dig 'em all. If I happen to locate a deep silver coin, I immediately flip over to the all metal mode and dig every other signal within a couple of feet, no matter how weak. This strategy has netted me quite a number of old silver coins, resulting from small coin "spills" in bygone days.

Thanks for those intriguing test plot results..Jim.

 

[duggr]

Jackalope
Quarter at 12" was detectable with solid iron tone and VDI mostly on #14.

I did the same test in my area last May and had exactly the same results! What was surprising to me was that my Whites XL Pro would pick up the Quarter and I.D. on the Target I.D. with an
up scale reading,signaling to me that I should investigate the target further.....

 

[ShawnP]

What would it do on the 12" quarter if you disc'd iron out?

 

[Jackalope]

Went back to the test garden with F-75 settings as before. Clad quarter at 12" gave repeating iron grunt with VDI mostly on #14 at Disc 3, 6, 9, and 14. At Disc. of 15, lost everything except a sputter. At Disc of 21 thru 65 found high tone repeatable in about a 45 degree segment of the total 360 circle and VDI jumping in the 80's and 90's.

Ron