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Nugget Detectors & Target ID Normalization For Jewelry?


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That brings me to another question. If you take the natural response of a single frequency machine, would a gold machine like the Gold Racer be better in high aluminum trash areas for cherry picking out gold? I am sure general coin shooting would be trickier as you start to lose the gamut on the higher conductors. Here is the ID scale on the Makro Gold Racer @ 56khz. I have a stupid thought in my head that I maybe able to use that to cherry pick some parks here that are just blankets of aluminum. I have sniped out the easy copper and silver but the can slaw is brutal.

56khz id range.jpg

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3 hours ago, kac said:

Here is the ID scale on the Makro Gold Racer @ 56khz.

Gold-Racer_dTIDs.jpg.376a737c443bfdf30ca26506c080cc30.jpg

I'm sure someone who has used the Gold Racer can answer better than I, but I'll give it a try.

No.

I suspect the chart is really just showing typical response digital TID ranges.  For example, I think you could find/make pieces of iron that would pretty much cover the entire range.  You might not be able to get the super low dTID's for the higher conductors but I suspect you could fill a lot more boxes than shown.

In particular, the Gold Racer's primary goal is finding naturally occurring gold.  I'm assuming that's what the gold column represents -- typical sized naturally occurring gold, not your usual gold jewelry ring.

Whaddaya want, a free lunch?  😄

P.S. Hope I'm wrong because your thinking outside the box would be a revolutionary trick -- discriminating gold jewelry from aluminum trash.

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42 minutes ago, kac said:

That brings me to another question. If you take the natural response of a single frequency machine, would a gold machine like the Gold Racer be better in high aluminum trash areas for cherry picking out gold? I am sure general coin shooting would be trickier as you start to lose the gamut on the higher conductors. Here is the ID scale on the Makro Gold Racer @ 56khz. I have a stupid thought in my head that I maybe able to use that to cherry pick some parks here that are just blankets of aluminum. I have sniped out the easy copper and silver but the can slaw is brutal.

56khz id range.jpg

I don't have a Gold Racer, but that chart makes no sense for typical aluminum targets (pull tabs, can slaw).   It makes sense for everything else and makes sense if you are talking full size aluminum cans.  I have run the Deus at 58 khz small aluminum sounds pretty much like small gold although there is a nuanced hollowness to the tone.  Pretty subtle though and not something you can really notice unless you are swinging over an aluminum and gold target that are adjacent to one another.

And GB's point holds as well that "mass dependent" metals such as aluminum and lead whose conductivity and magnetic field strength properties are highly influenced by the mass of metal present, can present themselves as just about any target ID in the range.

There indeed is no free lunches in detecting just a variation in the cost of the lunch, and the biggest practical joke that physics and nature have played on detectorists using VLF IB machines is that there really hasn't been a machine made yet that can reliably convey to the user the difference between a middle of the road gold target and a middle of the road aluminum target.

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XP machines normalize their ID's as far as I know. If you change frequencies your id's for a given target is pretty much the same, correct?

That chart is the raw unfiltered id mapping from Nokta/Makro user manual and is same chart used in both the Gold Racer and Gold Kruzer. These are prospecting machines with higher frequencies than the MDT 8000 and others.

So Are the ID's the same across all frequencies on the MDT?

I don't like boxes 🙂

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14 minutes ago, kac said:

XP machines normalize their ID's as far as I know. If you change frequencies your id's for a given target is pretty much the same, correct?

That chart is the raw unfiltered id mapping from Nokta/Makro user manual and is same chart used in both the Gold Racer and Gold Kruzer. These are prospecting machines with higher frequencies than the MDT 8000 and others.

So Are the ID's the same across all frequencies on the MDT?

I don't like boxes 🙂

XP Deus can run raw numbers or normalized. ORX is raw numbers only.

The MDT has a normalized 30 points of non-ferrous target id.

Tarsacci MDT 8000 User Manual

350342F3-C123-4689-AD41-9DADA98308F8.jpeg

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So what would be the numbers on id's with an xp machine with raw numbers? Anything like the Gold Racer?

Maybe split this thread to another in the right category?

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1 hour ago, Steve Herschbach said:

XP Deus can run raw numbers or normalized. ORX is raw numbers only.

It is really more complicated than that with Deus.  Deus can run raw or normalized (selectable) for the LF and x35 coils.  Normalized target IDs are normalized to 18 khz equivalents regardless of frequency which on the X35 coils are nominally 4, 8, 12, 18 and 25 khz (there is allowance for frequency shifting around those nominal frequencies on the X35).  The HF coils when used with Deus are raw only and normalization is not an option.

And regarding the ORX, all Target IDs are normalized to 18 khz regardless of coil and selected operational frequencies.  This is another subtle advantage of the ORX as it spreads the high conductive numbers out better when the HF coils are used with the ORX.  However, there is no option to run raw, un-normalized target IDs on ORX.

1 hour ago, kac said:

So what would be the numbers on id's with an xp machine with raw numbers? Anything like the Gold Racer?

Maybe split this thread to another in the right category?

If running raw, the answer varies with frequency but the tables below are consistent with my experience for the raw (un-normalized) target IDs and Deus running non-hf coils.  If the normalized IDs would be equivalent to 18 khz.  Above 18 khz everything around 30 and above gets severely shifted up and compressed into the high end of the scale.  A complete, crushed aluminum can will read like a quarter or half-dollar.

 

Deus scale 1.JPG

Deus trash.JPG

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Higher frequencies as used in gold nugget detectors make small and/or weak targets stronger. Small gold hits harder, and so does foil. Picking the right frequency and sensitivity can create a form of basic discrimination by making a machine insensitive to small and thin aluminum. People have different ideas about where to draw that line. I've often taken nugget detectors like a Gold Bug 2 to a tot lot and dug everything, including lots of small and thin foil. In theory though there is such a thing as too sensitive, and most gold jewelry has at least a little mass to it. Single post ear rings can be as hard a target to hit as exists, so having a hot machine is important if they are your target. People talk about the 1 carat diamond on a post, but frankly when I hunt micro jewelry I have a lot of fun, but the finds are rarely anything to write home about. It's a great way to collect broken zippers though! :smile:

Lower frequencies shift target id numbers to the low end, expanding the range for silver coins. High frequencies shift everything to the top end, compressing silver into a very small range, but expanding the spacing in the gold and aluminum range. I prefer that myself, as frankly if I'm coin detecting I usually do not care if it is a dime or a quarter. I'm digging them. And expanded gold range can help you identify and possibly avoid certain common pull tabs while minimizing the potential for lost gold.

I've fiddled around with this a lot over the years, but I always tend to come back to digging all non-ferrous in some chosen range, and so from a practical aspect it's not proven too important to me to have an expanded gold range. But that's just me. If you are into that stuff, get DFX Gold Methods. It applies to any machine really as far as the gold and aluminum nothing strategies discussed.

If I am hunting rings I often just dig clean signals that hit hard on one target id with no variation. The classic "round signal". That seems to work as well as any fancy notching strategy.

Normalization applies a calculation to raw numbers to equalize the results to a chosen frequency. Minelab refers to calculated "normalized" numbers as "bins". The un-normalized "raw" number has a multiplier applied and the result is tossed in the appropriate bin.

Low frequencies expand the high (coin) conductive range and compress the low (gold) conductive range. High frequencies expand the low conductive range and compress the high conductive range. Page 82 from Understanding Your X-Terra attempts to show what happens when low frequency raw numbers for a coin are mapped into the compressed high frequency range. Since the "bins" are smaller for coins at the higher frequency target id numbers will be less sure of themselves as they shift between closely based bin boundaries.

IMG_0433.PNG

 

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Great article on White's DFX Normalization It's hard to beat a DFX or V3i for playing around with this kind of stuff. Too bad the Equinox can't shut off normalization. Be great to expand the low end and shove all the coins to the top.

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8 minutes ago, Steve Herschbach said:

Great article on White's DFX Normalization It's hard to beat a DFX or V3i for playing around with this kind of stuff. Too bad the Equinox can't shut off normalization. Be great to expand the low end and shove all the coins to the top.

Perhaps ML is compiling our wish lists for Equinox (switchable pitch (vco)/tone ID audio, mixed mode, true threshold, and target ID normalization options) for the Multi IQ version of the CTX.  

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