To test whether it can penetrate the ground to any significant degree, we would have to bury that particular 0.16 gram nugget to 2" depth you have previously suggested in that particular soil. I am referring to the test on the video that you criticize. NOW, it is already known to us from Bearcat's videos that a nugget of very much the same size can be detected sitting on TOP of iron rock at just about 2 inches with nothing but air in between. In the very best scenario (ground = air) we could only hope to detect the buried 0.16 gram it if we press the coil onto the ground. Even 1/2 " above ground we would hear nothing, since we have already exceeded the maximum 2" in free air capabilities. So it can't be tested in 2" depth at all.
My way of testing it and the way I am going to run the test it once I have received my ATX is as follows:
The known fact is that I can't exceed the nominal 2" free air possibilities between the coil and the nugget.
Thus, I shall bury the 0.12 nugget, which I have, to only 1" tightly packed iron ground, which I also have, and will try to hear it with the stock coil 1" above the test ground (1" + 1" = 2") or closer if it doesn't work. If it works, then I will re-bury the nugget to 1 1/2" depth and try again. Hopefully there will be no need to go as close to the ground with the coil as to actually touch the ground. This test would be (I think) pretty close to what you'd like to see. Am I right?
Your sentence "It is of no concern whether the coil is 1 inch or a foot or whatever" makes no sense to me, and frankly I don't understand the logic of it at all.
Why would it not be of any concern how far off the ground the coil is? Any further away than 1 inch and we won't detect anything. How else can we perform the test if it doesn't matter the coil is a foot away or whatever, as you put it. Mind you, I am still talking about the same 0.16 gram nugget. After reading that sentence I somehow have a feeling we're not on the same page.