Gold rings and zinc memorials

[The Beep Goes On]

When jewelry hunting I have tried to dig quality signals in the zinc cent range and in the upper pulltab range as well. Zinc cents generally fall in the 50 to 60 range. The upper pulltab range is, to my way of thinking, from 30 to 50, although I think the highest pulltab I have found was about a 44. Zinc cents that have medium to high corrosion have a lowered VDI and show up in the upper pulltab range, usually in the 40's and sometimes in the 30's. They can produce a high quality signal. I wanted to see if the V3 could distinguish between large gold rings and zinc cents to save myself some frustration and time.

I tested three gold rings and three zinc cents that all have the same approximate VDI. I have only included pics of the Analyze and Probe screens since the Search and Pinpoint modes offered no distinguishing characteristics.

The tests were done using the stock Coin and Jewelry program with the Eclipse 5.3 (6x6) concentric coil.

Targets & Analyze and Probe Screens

The targets
http://www.thebeepgoeson.com/images/gr_z_targets.jpg

10K Plain Band - Size 9 - 4.7g
http://www.thebeepgoeson.com/images/gr_1_analyze.jpg

14K Plain Band - Size 10 - 7.8g
http://www.thebeepgoeson.com/images/gr_2_analyze.jpg

18K Plain Band - Size 11 - 7.0g
http://www.thebeepgoeson.com/images/gr_3_analyze.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_1_analyze.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_2_analyze.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_3_analyze.jpg


10K Plain Band - Size 9 - 4.7g
http://www.thebeepgoeson.com/images/gr_1_probe.jpg

14K Plain Band - Size 10 - 7.8g
http://www.thebeepgoeson.com/images/gr_2_probe.jpg

18K Plain Band - Size 11 - 7.0g
http://www.thebeepgoeson.com/images/gr_3_probe.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_1_probe.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_2_probe.jpg

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)
http://www.thebeepgoeson.com/images/z_3_probe.jpg

From this quick test it appears that there are four possible differences:


The Analyze accuracy percentage is lower for the gold rings.
The zinc cents, on average, seem to appear larger in Analyze than the gold rings. While testing, I varied my sweep speed to see if this held true and, in general, it did.
In Analyze, the 22.5KHz curve is closer to the 2.5KHz curve for gold rings in comparison to zinc cents.
The Probe display shows some major differences; the Phase is quite different as is the Strength. I can understand the phase being different, but not sure why the Strength would vary.


Please keep in mind that this was a quick test without many targets. It was also done in a benchtest environment, so your mileage may vary.

I will put this information to use when I go hunting from now on and will update this article with the results.

HH!
TBGO

(this is a re-creation of the article at http://www.thebeepgoeson.com/display.asp?page=Gold_Rings_Zincolns)

[coinnut]

Definitely differences in the probe section, but not in the analyze mode. If you could find only one difference in any area of the machine, then it would be worth the effort. There has got to be some repeatable difference between pull tabs, zincolns and gold. The trick is to find it and get used to using it. I hope you are on to something!!

[The Beep Goes On]

Yeah...Phase may be the key. It may seem like Zooming on Ground Tracking, etc. to do a Probe may be a hassle, but, if it works, it will be faster than digging a hole. I plan on doing probe readings on all targets that hit like this and dig them regardless to see how reliable it is.

[coinnut]

Yeah...Phase may be the key. It may seem like Zooming on Ground Tracking, etc. to do a Probe may be a hassle, but, if it works, it will be faster than digging a hole. I plan on doing probe readings on all targets that hit like this and dig them regardless to see how reliable it is.


On the V3i, didn't they get rid of some of them functions? How ironic would that be if it were able to help distinguish gold, even if only some of the time, and they get rid of that feature with the upgrades. lol Love to know how it turns out. Gold is rather rare, even in parks, so it may take you some time before you hit on one that you think is gold. Good luck!!

[The Beep Goes On]

The V3i has some differences, but the Analyze feature and Ground Probe will provide the same info. There is a Polar Plot Analyze feature that is added, but the regular Analyze is still there. They removed Recommended Gain, but that's not important.

Finding another ring in that VDI range could take a while, but avoiding zincolns would increase your swing time regardless of whether you ever found gold or not.

[angellionel]

That is very good and interesting information. I can see where using phase may offer an advantage. Keep us posted on your findings on using the probe readings in your hunts.

[Manuellar]

To further differentiate between Zinc and Gold, you use 22.5kHz with Mormalized OFF. Expand the VDIs block and, at least, better identify zinc. Gold VDIs will always vary depending on their composition.
It is only an aid and advice.
Regards ;)

[The Beep Goes On]

Thanks Manuellar. If you look at Neil's Spectra V3 Normalization Comparison (http://www.freewebs.com/neilinwestjersey/v3anddfxtips.htm) you will find that the zinc cents and other items sharing the same VDI (like big gold rings) usually have the same non-normalized (raw) distribution.

For instance, if you look at the zinc cent data and compare it to a lead bullet (no comparable gold rings in chart, but we'll turn lead into gold for this comparison) it is apparent that, even with normalization off, it would be hard to tell the difference.

Normalization off, I'm sure, might give you some clues, but I don't think it would provide any concrete indications.

Target: Lincoln Cent (Memorial) 2007
Best Data (Multi Freq): 56
2.5KHz Norm: 54
7.5KHz Norm: 55
22.5KHz Norm: 62
2.5KHz Raw: 32
7.5KHz Raw: 62
22.5KHz Raw: 82

Target: Musket Ball - Lead
Best Data (Multi Freq): 54
2.5KHz Norm: 55
7.5KHz Norm: 53
22.5KHz Norm: 52
2.5KHz Raw: 31
7.5KHz Raw: 59
22.5KHz Raw: 77

If anything, according to the data, it looks like 22.5KHz Norm has the biggest difference. Of course, we're talking theory here...it remains to be seen if any of this will work in the field.

[Manuellar]

The Neils table is made for DFX. There is variation between the VDIs of DFX and VDIs of V3.
I have no penny of Lincoln for testing. Normalized 22.5kHz OFF, will give greater variation VDIs. Greater variation the smaller VDI the gold object.
If you are looking with best data, when you have a dubious goal, switch to 22.5 and observe the variation of VDI, observe the size Scan in ANALIZE. It will also help.
Sorry, I can not explain better.
Regards

[The Beep Goes On]

The DFX chart on that page of Neil's site was created by me long ago. Look again and you will see a chart done by Neil for the V3. The data comes from Neil's Spectra V3 Normalization Comparison Excel spreadsheet.

I'm just thinking that checking Phase may be mentally easier then figuring out normalized vs non-normalized VDI readings.

[The Beep Goes On]

BTW - If anyone wants to help test Phase as a reliable indicator...


Add Ground Tracking to your favorite program's control bar using Extend (Configuration)
When you encounter quality signals in the range of the test targets, Zoom on Ground Tracking, Zero the readings (with coil in air), lower the coil to the target and check the Phase (watch the values - you'll know when you're over the target)
After digging several to get a feel for the Phase values, see if your pre-retrieval guessing improves (in this case, very simply, zincoln, or not zincoln is the question)

[The Beep Goes On]

FYI - I did some further testing in as close to real world conditions as I could and it looks like it is very difficult to tell the difference, even using Phase.

So, I'm going to keep my eye on Phase and the other potential indicators, but I am not optimistic.

[xzlr8n]

Moral of the story - &quot:grin:ig it All. I've had lots of IH's and Wheats come in at the Zincoln VDI range, They were at older houses so I felt compelled to dig the signals, glad I did and was surprised too.

[The Beep Goes On]

Moral of the story - &quot:grin:ig it All. I've had lots of IH's and Wheats come in at the Zincoln VDI range, They were at older houses so I felt compelled to dig the signals, glad I did and was surprised too.


Yeah, it always seems to come back to that. The tests were done with modern jewelry sites in mind where zincolns can be a problem. We'll see if this goes anywhere...it will take a few months to see if any of the indicators, or a combination of indicators, show any promise. It's an avenue worthy of exploration imo. I refuse to pass up good sounding targets knowing it could be gold or something unexpected...just trying to weed out the zincs. Most are easily discernible when they fall in the 50's - it's usually only the corroded ones that give a good signal with a lower VDI. If you decide to dig good sounding zincs it can eat up your day.

[xzlr8n]

If you decide to dig good sounding zincs it can eat up your day.


I hate Zincolns for this reason, the Mint should just stop making them. From what I hear it costs 1.6 cents to make 1 cent :confused:. I usually end up throwing the darn things away because they're too far gone to re-circulate :bangahead01:.

[CyberSage]

This is a great thread! I got out today for awhile and all I could think about was this thread. I dug so many Zincolns. Thanks for the great information. If you make a break through in identifying gold rings send me a PM. I would not share it openly here on the forum. lol Thanks again.

Jack

[The Beep Goes On]

This is a great thread! I got out today for awhile and all I could think about was this thread. I dug so many Zincolns. Thanks for the great information. If you make a break through in identifying gold rings send me a PM. I would not share it openly here on the forum. lol Thanks again.

Jack


Cool...sooner or later one of those good sounding zincs wil be a honkin' gold ring. I guess, if you decide to dig them, quick retrieval is the only way to minimize the time spent on them.

[texasboy112]

Thanks for all of your work; this certainly is a lot of food for thought. I'll be keeping an eye open for this in the future. thumbsup01 Your efforts are appreciated...