Is this the right area ......

Yes, post it here. We can always move it later depending on how it develops.

Here's where I'm at...

Got an 8" deep test garden with my local soil. We're leaning more toward claylike sand than anything else and it varies here and there (gravelly to loam like.)
(GTI 1500, 9.5 concentric standard imaging coil).I am at 6 on the Sensitivity. Currently at 1 bar below full battery power and am recharging for another test tomorrow. Unless there's a noticeable change with any of the following there will be no post.
These are essentially air tests as they are on the surface ?
(.01) = Wheat... reads from 8-9 with 8.5 the most hits. '43 steely is 3.5, '02 Indian Head and '08 are 7.5
(.05) = Buffalo and '48 were dead on 4.
(.10) = '45 Merc... 8-9 and ,05 8.5
(.25) = '01 clad... right on at 9.5
(.50) = '71... right on at 10.5
(1.00) = 1883 was 9.5-10.5 and 1923 same.
(1.00) = John Adams coin... 9.5 ( only a smidge larger than the .25 in size)
(1.00) = Susan B. Anthony another 9.5 ( like the quarter)
Marty

Not quite an air test since the ground matrix below the coin is also responding to the field from the detector

Excellent point....

Another thing I noticed was with a few penny tests at 6" + I was getting very little response. But, I was quick to make note of the very dry dirt that I dug 2 months ago. It reads a .5 out of 4 on our household plant soil moisture tester. Gonna work on that with a bit of remoisturizing. Also thinking I'll take that soil moisture tester out in the Spring just for fun and see what I'm getting into on an average day.
I suppose this is the best time for this sort of investigative work.
Thank you,
Marty

Will take some pics...

Won't be able to post them 'til I get to moms art gallery. Not enough ooomph here at home. The dirt is kinda settled in and firmish. I'm going to set it up a bit higher off the concrete floor just in case of interference. I had tried digging up a hole and put a coin in then back fill without tamping. Maybe a few more tested with tamped and not. I think the moisture level would be most important. I'm going to bring it up a bit. Chores first.
Marty

Back in the garden....

Today was more fun than the last time as I didn't pay as much attention to the visual display. I had watered the garden a few days ago and mixed it up real well. It now reads 2-2.5 out of 4 on our home plant moisture tester. Given the possible interference in the shop I set sensitivity at 7. Anything higher did give me weird hits.
First up was a .50 cent piece at the bottom (solid 8") and flat. Picked it up no problem. Next was at 8" and on edge. Still picked it up but needed to approach at a couple different angles to really get it. Quarter was next and flat at 8" it was detectable but had to try a couple different angles and on edge it was just hitting. The nickel, penny and dime at 8" barely hit didn't try on edge 'cause I figured they'd be tough to detect. I'm going out on a limb to say if I could jump the sens. up to 9 and maybe even 12 they'd register at that depth and possibly deeper. Gave it a try on 9 and they hit but that was in between other signals. IE water pipes, washer dryer, hotwater furnace, and the concrete floor.
Two odd targets were a very small silver toe ring and a standard size (2-3/4" x 2") brass belt buckle. Ring was registering all the way down to 5" flat and on edge although I had to work for it. The belt buckle was alot of fun ! For the heck of it I slid it under the garden tub which is about 2-1/2" inches off the ground. So that was an easy 10" and no trouble at all. Very solid and crystal clear tone. Hit at the penny level (8).
That looks long enough, thanks again for reading. I've learned much more about my machine today.
Marty
P.S. For other GTI owners....The 50 cent piece on edge displayed an "A" size meaning small target. The buckle was a "C" size.