Here are comments I posted elsewhere about this subject quite a long time ago. Deus LF coil used.
Deus owners,
Get you 3 or 4 half dollars or silver dollars,,or maybe even 7 or 8 quarters..
Stack the coins and sweep in Deus fast,,,,listen to what you here.
I used 3 and 4 silver dollars in my experiment .
Then start running your reactivity down and sweep and listen.
Do the same in 12 kHz , 8khz, and 4 kHz.
A person running Deus,, could in fact miss for example 4 silver dollars stacked ,, just under the surface of ground.
Btw I tried Racer with small coil-- no defects noted.
Make that a Racer 1 detector.
Well,, it does seem strange,, lowering reactivity setting,,, the stacks will come through in 12 and 18 kHz
And even at 0 disc setting--- same effect.
I haven't played with gB setting to see what effects it has.
And for gee whiz,,I isolated the 4 silver dollars (ungrounded them) but still stacked-- result just a tad better than being grounded and stacked.
I need to do an in ground test with my coins,,,ground balance seems to affect.
I will tape them together and bury and try with a correct ground balance--- in my ground it looks like it may work correctly,,but we will see.
Some follow up info.
Taped 4 silver dollars together stacked,, buried at 7" deep approx.
Air test and in ground test seem extremely similar.
My ground phase when balanced was 77.
Detector provides tone in all freq and reactivity settings 0-4,, didn't try 5-- I never use it
Silencer setting does,affect unite a bit when set greater than level 2.
Now if I run my ground balance up incrementally,,when I approach 84 and go up--- performance on giving full tone not so good,,and this length of tone gets incrementally shorter as GB is raised.
When the pop or extremely short tone is heard--- horseshoe seems to be telling the truth as far as nonferrous vs ferrous.
With high GB higher than say 83,, Lower reactivity setting to 2 and lower,, target hits very good,,,0 and 1 levels a little better than 2
Also,, full tones 0 disc,, tone sounds a bit better--- definitely sounds more like a nonferrous target vs maybe an iron false or iron rejected signal.
Didn't bury any deeper.