Gold rings and zinc memorials

[The Beep Goes On]

This is a recreation of the article at http://www.thebeepgoeson.com/display.asp?page=Gold_Rings_Zincolns.

When jewelry hunting I have tried to dig quality signals in the zinc cents 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 had 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.

Targets and Analyze and Probe Screens

The targets

10K Plain Band - Size 9 - 4.7g

14K Plain Band - Size 10 - 7.8g

18K Plain Band - Size 11 - 7.0g

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

10K Plain Band - Size 9 - 4.7g

14K Plain Band - Size 10 - 7.8g

18K Plain Band - Size 11 - 7.0g

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

Zinc Lincoln Memorial Cent (Zn 99.2% - Cu 0.8%)

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 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

 

[CROCK of COINS]

Nice job Beep!

Jerry

 

[nw1886]

That was a good post Beep. I've been skunked on the gold for my last three outings and maybe I should start digging more of those dang zincs, (Areas of this place I've been doing is absolutely carpeted with them though.) I'm finding it real interesting that the rings are hitting so hard with the 7.5 frequency for you. Early on, people were saying this was sometimes the case and with all my testing and rings found....almost always 22.5 and an occasional 2.5 hit. I don't know...it isn't like I'm leaving much stuff in the ground either. (Low zinc readings are always dug.) Rotten things from Hell is what I'm still saying!

It WAS an incredible day here in the Seattle area today! Skunked or not, it sure felt good to get out and dig! Was the first day that felt like the "new season for me" and guess I'll start it by digging the heck out of those zincs for a while. (My aching back!) HH

 

[The Beep Goes On]

Lol...so you definitely understand the motivation behind the tests!

 

[Jackpine Savage]

Confidence higher on rotten zincs than rings??? The analyze screen shows what freq hits hardest.. not the raw signal strength. The ground probe phase screen seems to capture more relevant target data, does it carry over on in ground targets? Rings are showing higher readings at 22.5, whereas the sine wave shows 7.5 peaking on all targets. Does the ground probe data update fast enough to be useful?

It seems to me that with all the effort put into the Vision (series) they could have come up with a 'pure' ring mode with a specialized confidence reading for rings instead of coins. Of course mid conductors in any kind of trash (modern or iron) are some tough targets... so forget those. However 'in the clear' rings should be 'relatively' easy to capture with a dedicated ring confidence program ...along with all the other mimicking trash of course.


JMHO Tom

 

[Rob (IL)]

??????????? Rob

 

[The Beep Goes On]

Confidence higher on rotten zincs than rings??? The analyze screen shows what freq hits hardest.. not the raw signal strength. The ground probe phase screen seems to capture more relevant target data, does it carry over on in ground targets? Rings are showing higher readings at 22.5, whereas the sine wave shows 7.5 peaking on all targets. Does the ground probe data update fast enough to be useful?

It seems to me that with all the effort put into the Vision (series) they could have come up with a 'pure' ring mode with a specialized confidence reading for rings instead of coins. Of course mid conductors in any kind of trash (modern or iron) are some tough targets... so forget those. However 'in the clear' rings should be 'relatively' easy to capture with a dedicated ring confidence program ...along with all the other mimicking trash of course.

JMHO Tom

I am not sure why the confidence is higher on the zincs. I'm guessing that the V is ascertaining the target's chances of being a pulltab (the first icon in that range). Or, more likely, it is using the frequency distribution and curves in some way to determine the %. I need to see if I can find some more info on how this number is determined. Anyone know for sure?

From what I've seen in the field (and on the bench), the prominent frequency is directly proportional to the VDI. Items with the same VDI will generally have the same dominant frequency. Smaller gold rings, I would agree, have 22.5KHz as the dominant frequency. I knew even before I started testing that the bigger gold rings would look just like the zinc cents as far as frequency is concerned.

The Analyze screen shows frequency dominance as well as frequency strength (amplitude, or height, of frequency curve).

As far as the usefulness of the Probe data is concerned, that will require some field testing to validate its worth.

HH!
Beep

 

[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 get used to the different values, but I am not optimistic.

 

[Jackpine Savage]

Can you get repeatable data sweeping the targets a little further from the coil? Maybe that would give data more in line with actual field conditions. I think I would look at the signal strength relative to the freq instead of the phase .

Tom

 

[The Beep Goes On]

Elsewhere there's a discussion going on concerning the discrepancy between the dominant freqs in Pinpoint and Analyze as compared to the Probe Strength values. Pinpoint and Analyze show 7.5KHz dominant. Probe Strength always shows 22.5KHz as the dominant freq. This was the case for all the tested targets. Don't know why...might be site specific.

The next step is to check the values on actual targets that fit the profile.

Tests have been conducted in the air and in the dirt using 5.3 and 6x10. The dirt tests nullified most of the air-test indicators, but I think it's an avenue worthy of exploration. It will take a few months to get a feel for what's going on with the values.

 

[The Beep Goes On]

I'm sure this is old hat for most of you, but thought I would post it anyway...

Target Ground Probe

• 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 the 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)

 

[JamesBondaka]

I just say no.....to air tests......unless your detecting coins flying around in the cosmos. To me, they show the detector is working and some indication of what it is detecting but not for use in the real world.

As per your question,,, about why the confidence is better on pennies(zincs). I would say that, because the standard is high, on the quality of minting When it comes to gold.....it can be a nightmare just to figure out what is the percentage of gold is to metal alloy. Example, I think 14k is 56 percent but depending on whoooooo produces it....it can be all over the place....It shouldnt be, but it does happen...especially foreign gold.

 

[jbow]

n/t

 

[jbow]

The probe also shows 22.5 strongest on all three zincs, the signal strength levels are a lot lower than they are on the rings. This is interesting, I wonder why all six analize screens show 7.5 hitting strongest? The analize screen also shows the 22.5 higher on the zincs than on the rings. I'm going to have to start using the ground probe more. I'm glad Anne posted for us to "zero" it with the coil on the ground to cancel both the ground and EMI.. I assume we would want a spot of clean ground close to the target. It will be interesting to use the probe both zero'd in the air and on the ground to see the difference. If the target VDI number is correct on the GP after zeroing on the ground... well, that is another good tool to use!!

J

 

[The Beep Goes On]

I has been noted that 22.5 is dominant in GP, but 7.5 is dominant in PP and Analyze. I have watched this while hunting this type of signal and it seems that 22.5 is always the highest (even if only by a little bit). The high strength numbers in the OP were too high due to the initial bench tests...they're usually much lower in the ground. This has been seen in two different locations where I've looked at the GP values. I am not sure why this happens.

Today, I zero'd in the air and on the ground and got the same approximate Phase VDI (it was a zincoln). I did not spend a lot of time looking at the numbers so this is not a for sure thing. Will keep checking.

To make sense of the numbers I've been thinking about field documentation methods since there is too much info to remember and sort mentally. You could write it down, use a voice recorder, take a screen pic or get it on video. This would be done in order to capture the GP data for more in-depth analysis.

 

[The Beep Goes On]

I just say no.....to air tests......unless your detecting coins flying around in the cosmos. To me, they show the detector is working and some indication of what it is detecting but not for use in the real world.

As per your question,,, about why the confidence is better on pennies(zincs). I would say that, because the standard is high, on the quality of minting When it comes to gold.....it can be a nightmare just to figure out what is the percentage of gold is to metal alloy. Example, I think 14k is 56 percent but depending on whoooooo produces it....it can be all over the place....It shouldnt be, but it does happen...especially foreign gold.

I think you are correct if your digging decisions are based only on bench test data. I always find it helpful to start with bench tests, move to staged ground tests and then into practical field testing. You get to know a target fairly well, as well as the effects the ground has on the target, by doing it this way.

As it turns out, the Accuracy % differences were an artifact of the bench tests. The rings and zincs were all around 80% when doing ground testing. I have to remember to note the % in the field and see if this holds true.

 

[jbow]

I'll let you know if I figure anything out (which is doubtful). I hate those stinkin linkins... and if they weren't bad enough with "dishonest Abe" on the front.. now some of them have him on the back too.... arrgh. Seriously, I think you could find one of those things on the moon.

Julien in "occupied Georgia"

 

[Diggler]

Are you guys saying that with the V3 it is hard to tell the difference between a lincoln and a zincoln? I sure hope I am wrong...

 

[Larry (IL)]

It shouldn't be hard, my zinc cents come in 55 to 60 depending on the ground, and copper cents are in the 70's....73 to 76 and bounce around a bit. A solid 76 is usually a dime for me.

 

[Diggler]

It shouldn't be hard, my zinc cents come in 55 to 60 depending on the ground, and copper cents are in the 70's....73 to 76 and bounce around a bit. A solid 76 is usually a dime for me.

Thanks. Not to hijack... Trying to convince myself to get a V3 instead of an Etrac. This is a great thread. I'll be following.