Pulltabs

[The Beep Goes On]

Hi - Thinking about getting a V3 (long time DFX user). One of the things I am most curious about is how the V3 helps to differentiate gold from pulltabs (if at all...?). Having the three spectragraphs and Analyze...does this allow you to confidently determine if it is a pulltab or not? For instance, if you had a gold band and a pulltab that had identical VDI; could you tell the difference? I realize that the alloys present in the pulltab are a factor. I ask because I read a review from a guy who said that if the Analyze screen had 22.5 at the top of the hump it was not a pulltab and if 7.5 was at the top it was a pulltab. I know this may be a generalization, but would appreciate any thoughts on the matter.

Thanks,
Beep

 

[robertk]

I've had plenty of pulltabs with 22.5 on top. I haven't found enough gold to notice any patterns of differences yet, though.

 

[The Beep Goes On]

Has anyone done any comparitive bench testing? By testing an assortment of pulltabs and gold rings I would think that you could probably make some useful observations that would be valuable in the field.

 

[CROCK of COINS]

Hello, If you go back to posts made in March/April...I think you can find some info.

Jerry

 

[CROCK of COINS]

Beep, Look at: http://www.findmall.com/read.php?66,936081,936265#msg-936265

Jerry

 

[The Beep Goes On]

That really helps C o' C...thanks!

 

[BHNugget]

I have my doubts as to any detector (available yet) with repeated reliability to differenciate the difference between tabs and gold.Just the difference in VDIs in tabs alone and gold jewelry alone makes it tough,then throw in ground conditions,depth,position of target,etc. and its asking a lot,even with the analyze screen.Ive come to the conclusion,if your going to dig gold jewelry,your also going to dig tabs.

 

[Larry (IL)]

I agree, and lots of them. All I hope to do is to better my chances by notching the central VDI # of common tabs with the iron grunt tone. I know, I might be notching out the ring that just happens to be exactly the same as a tab, but I think I would be willing to lose that ring and save me from digging thousands of the common tabs. I plan on using some of the ring enhancement programs already out there for the XLT/DFX, but instead of shutting off the audio in the notch, I will just assign a lower tone (iron) and I should be able to hear the rest of the VDI's above and below the tab. I guess what I hope to do is just "dirty" the audio on the common tabs enough that I would know it is most likely a tab and I would dig the clean audio targets in the gold range.

 

[The Beep Goes On]

That makes sense. By just changing the tone you don't have to worry about null masking, etc. Good point.

 

[The Beep Goes On]

I like what I've seen and read enough to get one...should be here middle of next week. Anyone want to buy a DFX?

 

[Larry (IL)]

I will know more about that Monday. I'll do some testing over the weekend with Rob, rcasio44, and see where the larger gold rings cross over to the medium frequency being on top and where the tabs and large slaw cross over. I'm pretty sure they are not at the same VDI. With that known, we will be able to assign tones to the two different groups hopefully with an audio and a visual ID, that should help eliminate some of the tabs and larger slaw.

 

[nw1886]

I've been doing some "adjusted" hunting in the secondary areas of lakes and schools. Digging it all and my pulltab to ring count fell way off in favor of rings. Two large men's class rings came in @ solid 26/27 and wasn't finding that many tabs. (Returned both rings with the magic of facebook and good school records!) It has to get really bad for me not to dig 'em.

 

[perchdoctor]

nw1886 has a point find vdi's that are in runs of three and don't jump numbers--- was my way of telling a gold rings from tabs, I would dig all of those for sure

 

[Taterhead]

I have had some gold, including 14k stamped wedding band, showing the 7.5 frequency as the dominant frequency in pinpoint mode. This was done conducting a surface-test on fairly highly mineralized ground. However, all other sample gold items (3-4 items) showed the 22.5 frequency as dominant in pinpoint mode. I did not run the "analyze" screen on either sample because I did not consider the possibility that the dominant frequency would be different between the two modes of operation, though it could be possible.

The village idiot,

Tater

 

[Taterhead]

Since we know that a VDI shift can occur due to high ground mineralization or proximity to another target, is it possible that frequency response could be impacted by the same conditions? In my case, in the exact same location most gold item pinpoint graphs were dominated by 22.5, while just one was dominated by 7.5. This makes me believe that it had nothing to do with proximity to other targets or ground mineralization, as these were the same for all test items.

Lastly, I am wondering if there are substantial differences in the alloys that are combined with pure gold to create 14k, or if they are consistent? Could it be that the alloy that is combined with gold can, in rare cases, cause the 7.5 frequency to dominate?

The village idiot,

Tater

 

[Jason in TN]

Beep, Look at: http://www.findmall.com/read.php?66,936081,936265#msg-936265

Jerry

Jerry thanks for posting up the link did several pictures on this subject a while back.
I have done a good bit of park and beach hunting with my Vision this summer have gotten my share of gold rings.
Just cashed in about $1500 in scrap gold a few weeks back.
There are times when I think I can tell then I look at all the tabs I dug to get those rings and I think maybe not.
The vision is hot on gold for sure.

Jason

 

[The Beep Goes On]

Alloy and size both have an effect. A big enough ball of foil or, as we know, an aluminum can, can have a higher VDI than its dominant alloy would typically have if it were coin-size. So, I think, and correct me if I'm wrong, but even a pure 24K gold ring will move into the 7.5 range once it gets to a certain size. I don't think any one V3 indicator will say "gold" or "pulltab", but if you utilize the tone, spectragraph, percentage, depth and analyze (size, sine-wave characteristics, sine-wave gradients (steepness), sign-wave variability, the dominant frequency and the graphical relation between the frequencies) you might be able to get more gold with practice. This may be more true concerning sites where you have identified and become familiar with the the dominant trash targets (pulltab varieties) at the location.

 

[Neil in West Jersey]

Solid 32 VDI

 

[BHNugget]

Nice one Neil,what does the VDI read on it out of the ground?

 

[Larry (IL)]

Rob, rcasio44, and I spent some time with gold rings and tabs on the V3 I'm sorry to say we really couldn't find a way to separate a tab from the gold. They all had good solid tight VDI's, and the Analyze screen looked good on all of the targets. 22.5 was dominant on both sets of targets and 7.5 took over being dominate at about 31 VDI on up on the rings I tested. I'm sure that would vary with the purity of the gold as well. So, going back to square one, I think the only thing that would help, is to "dirty" the central VDI # of the most common pull tabs in your area. For me that would be a big help but that still leaves a lot of tabs to dig. The gold ring purist would want to turn normalization off to spread out the spectrum of the 22.5 frequency and use a lower base threshold for narrower bars on the VDI display like Bob has done on the Hi Pro program.

Any other ideas guys/gals? Maybe working together we can come up with something that would help our % of gold ring/tab finds.