High VDI pennies

[gilfordberry]

OK, here's the deal. I've had the V3i about a week now and have spent maybe a total of 10 hours on it. I am digging a lot of targets that VDI in the 85-92 range at six to seven inches deep (and that's not an easy task in areas where shovels are a no-no, no evidence of a dig can be left, and the ground is as hard a concrete!!). So far, I am turning up memorial clad pennies (!?) only with these high VDI deep targets. So, this brings two questions to mind: First, am I doing something wrong? Analyze on these targets shows 2.5 KHZ dominant. Is there a way to separate the pennies from deep silver I'm not aware of? Second, if this is related to a wrap-around VDI problem (ground conditions causing normally 70 VDI pennies to show up as a 90 VDI) is it likely that a silver half or quarter (normally 83 to 90 or so VDI) is being wrapped around by twenty points as well, winding up as a -80 or so VDI and being discriminated out as a result??

I have noticed with my older XLT that deep pennies sometimes showed a higher than normal VDI number, but not nearly so prevalent as with the V3 - or maybe I'm just hearing a lot more deep targets....anyway, any advice appreciated.

Gil

 

[The Beep Goes On]

Hi Gil - You're probably hitting copper memorials (Cu 95%, Tin/Zn 5%) that usually read around the same as a clad dime. I'd need to know more about your settings and ground to make any further (meaningful) comments.

 

[Larry (IL)]

Something doesn't sound right, are you getting a good ground balance? Does this happen everywhere or in just one place? What program are you using and have you changed some settings. The more info you can give us, the more we might be able to help.

 

[nw1886]

High VDI's on deep copper is one of the things that works for me on old Lincolns and Indians. Deep dimes have a tendency not to spike up as high (with highs being in the low to mid 60's and if in non loamy soil, around 50 sometimes ). My DFX did this a little stronger than my V3, and since I ran that box for so much longer, came to see the pattern and would be sure it was almost always an Indian.

Now....hard soil like your dealing with plus deep modern? Be nice if you could remove this "little slice of hell"!!! (The only soil I see like this is in driveways.)

I don't know if I could help on a setting as I suspect this type of info is from copper halo rebound combined with weak signal/signal loss compensation. If there is an adjustment maybe someone has dealt with this "as a problem"? It's always been a recognized tool for me and never felt the need to "correct" a setting with this. If that is your typical soil, I suspect that it is not a Wrap issue and a lot of digging needs done to see a pattern on deep silver as well. Hopefully someone has crossed this road and found a solution for you! Again...is all soil like this in your area?

 

[yazoo]

You might try backing the sense down to 80-84 you might just be a bit hot. Does it false a lot too? Yazoo

 

[robertk]

For what it's worth, one site I hunt has the same problem. Pennies that VDI well into the dime/quarter range. They are all copper memorials and an occasional wheatie, and they are all deep (at least 6"). They even show the green bar dominant in pinpoint, just like a dime. For what it's worth, the other targets at the site do not do this -- dimes, quarters, and even zinc pennies all VDI right where they should. Hopefully your ground is similar and you just have to dig a lot of pennies to find the dimes.

 

[gilfordberry]

Hi Larry, am using mostly coin and jewelry program, tweaked just a bit to discriminate out some pull tabs (I still accept 15-20 and 34+ VDIs) and running 80/55 AC/DC with a gain of about 5 or 6. Soil is typical of Sou Cal - basically sandy loam that in times of low humidity turns rock hard almost like sandstone. (It turns to quicksand - or nearly so - when we get a good shaker or get a decent rain. lol) I've tried several of the programs, see a very similar pattern on them. And oh, yes, I am very careful with my ground balance. The only thing I can figure out is that - just maybe - its the "recycled water" these parks and schools are using to water (very infrequently, I'm afraid) the grass. That stuff is non-potable, very alkali, and could be stimulating halo effect. I do know it will turn a silver coin or ring coal black in a very short time and gobbles up those zinc pennies as bad as the salt beach. Hope I've described the problem correctly, and appreciate the help. Gil

 

[jbow]

I bet earthquakes can really make for a high sink rate in that sort of soil... like what was at 2" an hour ago could be a foot deep now. I never thought about that, does that happen?

J

 

[jbow]

You might try checking a few in 2.5 non-normalized. I guess you could try burying a dime and one of those pennies and check them against an undug one in 2.5 non-normalized. Maybe there will be a difference so you can tell.

J

 

[Larry (IL)]

The only thing I can think of that might help would be Salt Compensate or Salt Beach program due to the Alkali. Like others have said, it is just one of those things you might have to get use to. I experienced some of that too over the weekend when some cents were reading 82-83 thinking sure I had some quarters. I was hunting in unfamiliar ground and getting some weird VDI's. I'm pretty sure your problem is site specific and just different ground from the norm............

 

[TheMarshall]

Hi Larry, am using mostly coin and jewelry program, tweaked just a bit to discriminate out some pull tabs (I still accept 15-20 and 34+ VDIs) and running 80/55 AC/DC with a gain of about 5 or 6. Soil is typical of Sou Cal - basically sandy loam that in times of low humidity turns rock hard almost like sandstone. (It turns to quicksand - or nearly so - when we get a good shaker or get a decent rain. lol) I've tried several of the programs, see a very similar pattern on them. And oh, yes, I am very careful with my ground balance. The only thing I can figure out is that - just maybe - [size=x-large]its the "recycled water" these parks and schools are using to water (very infrequently, I'm afraid) the grass. That stuff is non-potable, very alkali, and could be stimulating halo effect. I do know it will turn a silver coin or ring coal black in a very short time and gobbles up those zinc pennies as bad as the salt beach. Hope I've described the problem correctly, and appreciate the help.[/size] Gil

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~​

Hi there Gi!..........

I think you have yourself, highlighted the probable cause of the 'high VDI's' G.

That water is possibly treated with a chlorine agent during its original usage, or afterwards.

Similarly, bleach sold as a domestic product has a very strong Alkaline base,as shown on my pH meter in the photo, it's off the scale.

That stuff just eats the ali/zinc.

It may be worth experimenting with using a lower single frequency? Why not try it.

Or.....

You will just have to wait for those heavy rainy days!

So G, you've solved your dilemma......well done........TheMarshall.



[attachment 163821 Alk.jpg]

 

[gilfordberry]

Hi Julien..I don't really know. But I do know that much of the Los Angeles basin, although a very dry climate, has a pretty high water table. The earthquake pros say a lot of the subsoil tends to liquify near a severe quake in areas with a high water table - causing anything built on top of that soil to sink. If you have ever been in an earthquake, you will be amazed at what flexing and bending what you think of as solid objects can do. I recall one in Sylmar, CA, when I lived there about twenty years ago...I was outside mowing the lawn when I heard/felt a low rumble like the noise an old truck might make climbing a hill. I looked down the street and the PAVEMENT had a wave in it coming toward me -- looked just like a wave at the beach -- and it was about 2 or 3 feet high. If I hadn't seen it, I wouldn't have believed it. It was a mild quake - only about a 4 or 4 1/2....but it's easy to see what an 8 might do (an 8 is 10,000 times as strong as a 4)....

I'm sure that any movement would tend to make more dense/heavier objects sink. Sure doesn't take a heavy gold ring long to sink down out of detector reach if a bunch of people are sifting the sand with their hands trying to find it....

 

[UtahRich]

OK, here's the deal. I've had the V3i about a week now and have spent maybe a total of 10 hours on it. I am digging a lot of targets that VDI in the 85-92 range at six to seven inches deep (and that's not an easy task in areas where shovels are a no-no, no evidence of a dig can be left, and the ground is as hard a concrete!!). So far, I am turning up memorial clad pennies (!?) only with these high VDI deep targets.
Gil

If I read you right, the clad/memorial pennies are at 6-7", the ground is concrete hard and you aren't allowed to dig? Can't pinpoint is concrete with a probe. Can't dig with a shovel. Time to move on down the road.

Good luck with greener pastures -

Rich

 

[jbow]

That's crazy. We have fault lines here in the SE USA that don't see much activity. I think that one day we will have a major quake here like they did on the New Madrid fault that changed the course of the Mississippi. I live in Cartersville, GA and there is a line called the Cartersville faultline. It runs close to a big dam on the Etowah river. Then up the road in Calhoun, GA it is only a few ft from the dam at Carter's Lake. You can see pics of it... it amazes me that they decided it was safe to build dams on faultlines because there isn't a major quake in our history...

This is the fault just below the Carter's Lake dam:

Julien

 

[Neil in West Jersey]

n/t

 

[nw1886]

If the soil is like that, it is more akin to a beach with a compaction component. That's miserable!! At first blush, thinking that seismic activity could cause sinking of small objects seemed off but......in sand and all the micro tremors that area sees, bet it does contribute.

The thing that got me thinking on this was an old railroad bed that showed signs of deeper objects than normal. All the adjacent banks have this sandy/silica ladened soil that's original to the old coal mining days. (Whiskey bottles at a foot and a half with little build up soil.) Never found a coin in this spot and it was high high use? They are just too deep!

 

[gilfordberry]

Well, turns out my problem was entirely site-specific. When I finally got around to trying some other places I had no problem at all with higher-than-normal VDI numbers. In fact, I dug some deep pennies and they read around 70, just like you'd expect. Guess the problem had to be either the halo effect from the chemicals/watering, or natural mineralization, or a combination of both. But anyway, I'm glad I finally got away from that site - trying to dig deep targets in very hard ground without leaving evidence of having done so is too much work......especially if your solid 87 VDI turns out to be a memorial penny.