AT pro and vdi numbers

[ewtaylor]

Went detecting this afternoon at two different locations. The first was a fresh water beach. Water way toooo cold for entry so I stuck to the waters edge. Came away with some pocket change and several junk earrings. I almost always find junk jewelry here and the only reason I went was hoping the water levels had went way down. They had not. So off to another site located in town. I used the standard stock coil here and will probably switch to the sniper next because of the trash signals. I did manage to pull out some old lincolns, one being a '49s. Also found a kid's belt buckle with guitar on it.
My question is this, the VDI numbers were really high. All the pennies were reading in the 80's. One hole held 2 pennies and it was reading high 80's. Usually I find pennies in the upper seventies / low 80's. Dimes in the low 80's and quarters in the upper 80's.
The dirt is very black, which surprises me as most places around here have been attacked by earth movers. I ground balanced and it stayed about 85. Anyone else had this odd situation? Do you think it was the dirt ?

thanks

 

[JimmyCT]

Like you mention, it could be that the black sand skewed the numbers.

 

[ewtaylor]

Gonna go back and edit my post. The soil was black as I had moved on to an inland site here in town, no sand. But thanks anyway.

 

[John-Edmonton]

I think it was either the dirt or the oxidation on the coins. I sometimes experience the opposite effect. Some of my locations are very alkaline. The pennies will read in the 60's. Yet, in my normal soil, they will read in the 80's. I guess that's part of the learning curve be get, for next time we hunt those places.

 

[JimmyCT]

black sand or dirt or as John mentions "oxidation" could possibly skew the VDI. When in doubt, dig and learn. HH

Gonna go back and edit my post. The soil was black as I had moved on to an inland site here in town, no sand. But thanks anyway.

 

[MikeLab]

No expert here on water hunting, but if the numbers are off I assume ground balance is incorrect. Some areas do not auto balance well so I would try to use manual balance and just move it one way or the other (I think down is what you need) to see if you can get it right on.