Pull tabs

[Coin-Digger]

Ok, I Just purchased a Deus! Great machine! Ran it through my small coin garden. But, I was air testing some targets using the x-y screen. Pull tab was hitting VDI of 55 no matter what I did. The nickel was around the same. On the x-y screen. They both were A to C coordinate. Top right to bottom left. No difference between the two at all!

So my question is. What can I do to tell the difference?

Oh and I went to Non motion Aud disc. Both were the same there as well! Other than that, I have no problems with old rusty bottle caps or anything else for that matter!

 

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[SD51]

Sorry, I don't have a Deus but are you talking about the old style of pulltab or the current one?

 

[smokeythecat]

The trouble with not digging them is some gold hits at 55-56. I generally dig them, and two I thought for sure were pulltabs were gold rings!

 

[Coin-Digger]

Sorry, I don't have a Deus but are you talking about the old style of pulltab or the current one?

It was a rectangular pull tab. The Beaver Tail I could disc out.

 

[Coin-Digger]

The trouble with not digging them is some gold hits at 55-56. I generally dig them, and two I thought for sure were pulltabs were gold rings!

Yeah, I would of dug that one for sure! I was just wondering about a way to tell quicker. It’s a learning curve for sure in that department

 

[HuntinDog]

I dig a LOT of pull tabs.
About the only way to tell is by sound.
Tabs have a hollow sound to the edge.
Hard to hear, so that's why I dig a bunch...

 

[smokeythecat]

Every single time I thought I was digging aluminum it was gold! Words for the wise! I can tell the difference about 90% of the time, but that last 10% - priceless!

 

[dirtlooter]

I dig them for a while then skip them until the next time and I repeat but I dig them.

 

[vferrari]

Bottom line, you can't really tell the difference between them. It may be possible if the pull tab is mangled that you will get a distorted edge to the tone (might also show up on the X-Y screen), this is also true of mangled can slaw. Coins and rings tend to give a purer, fuller tone, but it is very subtle. Understanding Tonal quality vice visual TID is the key to Deus. The x-y screen can sometimes help, but as you saw, on a "pristine" pull tab, it is really not possible to tell the difference.

Basically, you are just playing the odds. It's a pure numbers game. There are more pull tabs than nickels and more nickels than gold jewelry out there in the US. It is really site dependent, but a rule of thumb is 75% - 80% will be pull tabs, 15 -25 % nickels, 1 to 5% some type of gold. So play the odds at your peril or suck it up and dig 'em all to be sure. Just set your expectations, accordingly. I figure it's just always going to be aluminum, so when it is a pull tab, shrug and move on. But just when you least expect it - jackpot!

Just the nature of the biz. Some sort of cruel joke by the detecting gods that aluminum and gold will have similar TIDs. There is no real magic bullet on this.
Some detectors, like Equinox, have more stable TIDs which can help - nickels usuually lock in at 13 whereas pull tabs will fall at 14 or 12, but corrosion in the nickel can change the TID and gold depending on size, shape, and purity, can fall anywhere in that rannge. The Deus has more numbers but tends to be less stable or repeatable on visual TID in the field. Plus factors such as target corrosion, soil conditions and nearby targets such as iron can pull TIDs down. Using disc on on the Deus helps to mitigate iron-non-ferrous TID down averaging and Deus disc doesn't affect depth like it does on other detectors as long as you keep it 15 or less (I like to keep it between 7 and 10).

Anyway. HTH.

 

[Coin-Digger]

Bottom line, you can't really tell the difference between them. It may be possible if the pull tab is mangled that you will get a distorted edge to the tone (might also show up on the X-Y screen), this is also true of mangled can slaw. Coins and rings tend to give a purer, fuller tone, but it is very subtle. Understanding Tonal quality vice visual TID is the key to Deus. The x-y screen can sometimes help, but as you saw, on a "pristine" pull tab, it is really not possible to tell the difference.

Basically, you are just playing the odds. It's a pure numbers game. There are more pull tabs than nickels and more nickels than gold jewelry out there in the US. It is really site dependent, but a rule of thumb is 75% - 80% will be pull tabs, 15 -25 % nickels, 1 to 5% some type of gold. So play the odds at your peril or suck it up and dig 'em all to be sure. Just set your expectations, accordingly. I figure it's just always going to be aluminum, so when it is a pull tab, shrug and move on. But just when you least expect it - jackpot!

Just the nature of the biz. Some sort of cruel joke by the detecting gods that aluminum and gold will have similar TIDs. There is no real magic bullet on this.
Some detectors, like Equinox, have more stable TIDs which can help - nickels usuually lock in at 13 whereas pull tabs will fall at 14 or 12, but corrosion in the nickel can change the TID and gold depending on size, shape, and purity, can fall anywhere in that rannge. The Deus has more numbers but tends to be less stable or repeatable on visual TID in the field. Plus factors such as target corrosion, soil conditions and nearby targets such as iron can pull TIDs down. Using disc on on the Deus helps to mitigate iron-non-ferrous TID down averaging and Deus disc doesn't affect depth like it does on other detectors as long as you keep it 15 or less (I like to keep it between 7 and 10).

Anyway. HTH.

Thanks Ferrari! Very useful info again as always! Yeah, my odds is 99% aluminum and 0% Nickels. 1% gold though! The middle tones on either one of my detectors has nearly always let me down. I’m sure I’ve passed over a V nickel or buffalo. They are on my bucket list! Thankfully I have some superb digging equipment. Backhoe, rootslayer, and a leashe digging tool LOL! I will find one hopefully in the near future!

 

[vferrari]

I have a few places where that backhoe could be useful, lol.

 

[Coin-Digger]

The backhoe comes in handy in some farmland where I live.

 

[Doug H]

Can I ask a stupid question that I'm sure has been asked before. Why cant the detectors tell the difference between gold and a pull tab or gold and a bottle cap? To me they are two totally different metals. Why cant the manufacturers make gold ring up as it's own set of numbers. Just asking.

 

[Jerry-Wi]

You did not say what frequency you are running. I often use 17 Khz and find there is a difference between pull tabs and Nickels.
Generally tabs come in at 66 to 68 and nickels are from 61 to 64. I say generally because there are exceptions and I will get a low 60's reading and dig up a pull tab.

However when I get a 61~64 reading I am 80% certain that it is a nickel.

Having said all that remember that metal detectors are notorious liars and the only way to know for sure is to to dig it up.

 

[Coin-Digger]

12 khz

 

[vferrari]

Can I ask a stupid question that I'm sure has been asked before. Why cant the detectors tell the difference between gold and a pull tab or gold and a bottle cap? To me they are two totally different metals. Why cant the manufacturers make gold ring up as it's own set of numbers. Just asking.

Because the metal detector is not doing a metallic analysis. It is inferring what the target is based on the phase shift, strength, size, and shape of the magnetic field that is induced into the target by the transmit coil (and subsequently detected by the receive coil). Electromagnetic properties of metals like conductivity and magnetic permeability (which determines magnetic field strength and phase shift of the field induced in the target and "coupling" with the receive coil) and target shape affect the sensed magnetic field of the target which the detector uses to "ID" the target, but it is only a guess as many external factors such as soil type, nearby targets, and target corrosion and damage can distort the field from the "ideal". Also, it just so happens that aluminum pull tabs, nickels, and gold rings of similar size are a very similar in these electromagnetic properties as far as the detector is concerned and the phase shifts are similar, so most metal detectors have trouble differentiating between these electromagnetically similar targets. Higher conductors like copper and silver are much easier to differentiate because they result in large phase shifts, iron is also easier to detect and discriminate because it is ferro-magnetic and this affects the magnetic coupling to the receive coil which can be easily determined by the detector (though field distortion can cause falsing). Some multi-frequency machines like the Equinox can eek out some additional information as the target is hit with different frequencies and behaves slightly differently to each of those frequencies such that there is some additional capability to differentiate between a nickel and a pull tab but corrosion and soil conditions can still fool the machine.

Bottom line: it's complicated, but these mid-range conductive metals like brass, lead, aluminum, gold, and nickel of similar size are hard to differentiate from each other.

 

[RustyGold]

I have found that pull tabs do have a certain “hollow sound” that is difficult to explain. I can usually call it before I dig it but not always. The X/Y screen is my best friend.

 

[Coin-Digger]

Yeah, the X-Y screen is pretty good on the ole beaver tails. Not so much on the rectangular pull tabs! I actually found a dime in the same hole a pull tab the other day. It was a clad dime. The reason I went ahead and dug the tone up I’m sure!

 

[SD51]

It was a rectangular pull tab. The Beaver Tail I could disc out.

Think about it for a minute... the rectangular (new style) pull tab was designed to prevent people from getting accidently cut when opening a can since the old style pull tab would completely separate and had sharp edges. Also the rectangular pull tab was designed to stay attached to the can.

Now the real question... a person (idiot) has to really work (a little) to remove the rectangular pull tab from the can so they can throw it on the ground. They must have reached a senior level of litterbugidness!

Sorry, have to rant a little, just came in from snow blowing 6" of snow!

 

[Coin-Digger]

Think about it for a minute... the rectangular (new style) pull tab was designed to prevent people from getting accidently cut when opening a can since the old style pull tab would completely separate and had sharp edges. Also the rectangular pull tab was designed to stay attached to the can.

Now the real question... a person (idiot) has to really work (a little) to remove the rectangular pull tab from the can so they can throw it on the ground. They must have reached a senior level of litterbugidness!

Sorry, have to rant a little, just came in from snow blowing 6" of snow!

Yep, it’s a pain in the a$$ sometimes! But, it’s all for fun and workout anyway! LOL