How exactly does the 2D VDI on minelab machines work?

[Smooth23]

Is there any information? I know we use the terms 'conductive' and 'ferrous' numbers, but we also know that those are not accurate descriptions. How's it really processing the target to get say a 10-40 vs a 12-40? As an example on my etrac, 10-40 would almost surely be a wheat penny where a 12-40 is likely a zincoln.

 

[IDXMonster]

You’re likely to get some cricket chirping on this one Smooth. Minelab isn’t going to put their propriety signal processing scheme out there for others to copy, and even if it isn’t under patent, they’re still not going to blabber too much. I don’t blame them. What we CAN do as end users is pay attention VERY closely to how your specific FBS machine reacts to certain things, and therefore make seemingly (and very likely legitimately) more intelligent decisions about whether or not to dig a target up. These machines take “cherry picking” to a higher degree of certainty about progressively sketchier signals, but of course the worst signals either have to be dug or left alone. And none of that addresses the original question…HOW exactly does it work? Well…I don’t know, past what is already out there on various forums. Would it help us to know the intimate details? Could we change anything more than what we can already change? No. So from our standpoint, while it would be neat for us dorks who just want to know, whether or not we do doesn’t change anything. UNDERSTANDING, as fully as possible at our individual skill levels, what is going on is a byproduct of hundreds, if not thousands, of hours of use. I’ve had my CTX for 6 years and still feel as if there is much to know. Same with my Explorers. The designers themselves likely haven‘t fully comprehended the overall abilities of these machines, and that goes for a lot of other brands and models for that matter. I can tell you that for me, the CTX has been a type of “magic wand”, as have the Explorers. The discrimination ability with discrimination actually applied or not, and their ability to convey USEFUL AND ACCURATE INFORMATION has been the best I’ve used so far when it comes to coin hunting in difficult public sites. A fellow member here said it the best one time…”FBS machines don’t SEPARATE, they SORT.” And the way they do it is nothing short of incredible, whether we know how they do it or not. I’d still like to know though, cuz you know…I’m a dork.

 

[Smooth23]

You’re likely to get some cricket chirping on this one Smooth. Minelab isn’t going to put their propriety signal processing scheme out there for others to copy, and even if it isn’t under patent, they’re still not going to blabber too much. I don’t blame them. What we CAN do as end users is pay attention VERY closely to how your specific FBS machine reacts to certain things, and therefore make seemingly (and very likely legitimately) more intelligent decisions about whether or not to dig a target up. These machines take “cherry picking” to a higher degree of certainty about progressively sketchier signals, but of course the worst signals either have to be dug or left alone. And none of that addresses the original question…HOW exactly does it work? Well…I don’t know, past what is already out there on various forums. Would it help us to know the intimate details? Could we change anything more than what we can already change? No. So from our standpoint, while it would be neat for us dorks who just want to know, whether or not we do doesn’t change anything. UNDERSTANDING, as fully as possible at our individual skill levels, what is going on is a byproduct of hundreds, if not thousands, of hours of use. I’ve had my CTX for 6 years and still feel as if there is much to know. Same with my Explorers. The designers themselves likely haven‘t fully comprehended the overall abilities of these machines, and that goes for a lot of other brands and models for that matter. I can tell you that for me, the CTX has been a type of “magic wand”, as have the Explorers. The discrimination ability with discrimination actually applied or not, and their ability to convey USEFUL AND ACCURATE INFORMATION has been the best I’ve used so far when it comes to coin hunting in difficult public sites. A fellow member here said it the best one time…”FBS machines don’t SEPARATE, they SORT.” And the way they do it is nothing short of incredible, whether we know how they do it or not. I’d still like to know though, cuz you know…I’m a dork.

Thanks for the response. Kind of strayed from why I was asking the question though. Clearly they wouldn't want to give away their secrets. I'm more or less wondering why other detectors haven't picked up on this method? Why have only say 100 numbers for VDI like a Deus 2 when You could have 1750 or however many unique numbers the etrac or ctx have

 

[IDXMonster]

Why other manufacturers don’t use it could very well have to do with patents in that case.

 

[pulltabfelix]

I have a related question. Been using my CTX for about 8 months. now. Love it. It does well in my parks and baseball fields for cherry picking coins. In my areas coins 4-6" deep it locks on them and leave you no doubt you have a coin even mixed in with iron.
On deeper coins, I don't have much experience. That is because (I think) we have a clay layer about 5-6" deep. But another question about iron. Starting to hunt civil war relics with my CTX. Found a piece of CW shrapnel when in an open screen.
Is there anyway with the fe-co number to tell the difference between more modern metal and cast iron CW iron relics like shrapnel? I tried testing out the shrapnel against modern nails and not a big difference. Nothing like the difference between silver coins and poptops.

 

[sube]

Is there anyway with the fe-co number to tell the difference between more modern metal and cast iron CW iron relics like shrapnel? I tried testing out the shrapnel against modern nails and not a big difference. Nothing like the difference between silver coins and poptops
No we could say the same for silver coins the difference between them and iron bigger spread between the ID compared to the pull-tab so
does not matter what is mixed with iron if the ferrous content is more than the conductive metal in iron it well display iron then again iron comes in all sizes so even if you got a certain ID for one piece of iron the next piece would ID different . sube

 

[Smooth23]

My suspicion is that the 'ferrous' number?(the one on the left) is determined more by shape of object. so if its more uniform it'll be closer to 12, less uniform response curve will be higher/lower. Not sure if thats true or even makes sense, but I can see someone building some signal analysis around that.

 

[LTDigger]

Is there anyway with the fe-co number to tell the difference between more modern metal and cast iron CW iron relics like shrapnel? I tried testing out the shrapnel against modern nails and not a big difference. Nothing like the difference between silver coins and poptops
No we could say the same for silver coins the difference between them and iron bigger spread between the ID compared to the pull-tab so
does not matter what is mixed with iron if the ferrous content is more than the conductive metal in iron it well display iron then again iron comes in all sizes so even if you got a certain ID for one piece of iron the next piece would ID different . sube

The 3030 is my oldest machine 10 years now. Target separation has always been my toughest decision because many areas I hunt are very old but have lots of both iron and modern trash. Have always favored ferrous coin a bit over modern trash even though it falses a bit more but doesnt look like a coin on the screen. Modern trash i believe is a little faster in these site if i'm correct which is essential with the slower 3030. Opinions?

 

[IDXMonster]

The 3030 is my oldest machine 10 years now. Target separation has always been my toughest decision because many areas I hunt are very old but have lots of both iron and modern trash. Have always favored ferrous coin a bit over modern trash even though it falses a bit more but doesnt look like a coin on the screen. Modern trash i believe is a little faster in these site if i'm correct which is essential with the slower 3030. Opinions?

I think you’re basically doing it “right” LT. Lots of little iron, nails and milder ground….Ferrous/Coin. Modern trash in higher amounts with more mineralized soil…High Trash with Fast ON. Of course you’ve found over a long time using it that sweep speed and angle are critical when analyzing. Lots of people claim to have the “secret sauce” as far as settings go, but there’s a reason modern machines have adjustments!
I‘m going out Saturday with mine to join a friend who uses one also. When hunting public ground where trash is present in varying amounts and types, and coins approach 10” on a regular basis…it works really well.

 

[jkline]

It is a great machine.

For high EMI areas, I got a nox, sold that, then picked up a Legend. Going to a single set of digits for target ID-- I can't get used to that.

 

[robinb]

I use the 3030 several times a week.
Iron always is a low ferrous number

I can reject stuff because of where the ferrous number shows.
Equally if its 01/02 its a bear bottle cap.