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Goldmaster 24K Target ID Question


LarryD

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I recently purchased the Goldmaster 24k. In preparation for my first outing I made a test bed of different materials in my back yard. I also printed of the Conductive Order of Metals which was set up based on the Whites Spectrum XLT.

So my test bed consisted of a nail, pulltab, penny, nickle, dime, quarter, gold ring. After setting up my detector based on Whites quick start guide I did my testing. Here are the visual target id results. I wanted to compare them to the Conductive Order of Metals

GMT 24k reading.                        nail 39   pulltab 91  penny 95  nickle 89  dime 97. quarter 98  gold wedding ring 94

Conductive Order of Metals       nail 0     pulltab 35  penny 56   nickle 28  dime 70  quarter 82  gold wedding ring 40

As you can not even close. So am I wrong in thinking the GMT 24k should follow the Conductive Order of Metals listing? Is there some other listing I should be looking at or is there no corelation at all? Thanks for any help.

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Your numbers are posted so as to add a little confusion, so let's puts them in numeric order:

Normal   nail 0  nickel 28   tab 35   ring 40  penny 56   dime 70   quarter 82

GK24k  nail 39  nickel 89   tab 91   ring 94  penny 95   dime 97   quarter 98

Discrimination systems do not tell you what metal you are detecting. Any metal can read almost anywhere on the scale depending on size. Also, the number range chosen is arbitrarily determined by the manufacturer. I assume you are using the standard White's -95 to 0 to +95 scale. There are many others, see the link below.

whites-v3i-target-vdt-scale.jpg

Where target id numbers end up is determined by frequency, and the result can be raw or normalized. Low frequencies shift numbers lower. High frequencies shift numbers higher. Normalization picks one frequency, and makes all results fit mathematically to make memorization of results easier. For historical reasons White’s normalizes to 6.59 kHz.

What matters is not the numbers, but the order of the numbers. The 24K is a very high frequency detector at 48 kHz and it is using raw target id numbers, so they are all compressed to the high end of the scale. As you can see the order remains the same.

In other words, what you are seeing is what I expect with this detector. Keep in mind this is not a coin detector, but a gold nugget detector, so the emphasis was not in matching coin detector target id numbers but in getting good ferrous and non-ferrous separation. Leaving the numbers as high frequency raw results increases the target spread on the low end and enhances the ability to separate ferrous and non-ferrous. Note that on the normalized White’s scale the range from ferrous to nickel is 28 points. On the 24K it is nearly double at about 50 points. The low end has far more spread between low conductive target id  numbers but the result is most coins lump together on the high end. See the V3i info at the link below for a good explanation of frequency effects and target id normalization.

Lots of reading and links here to fill in the gaps....

What Is Metal Detector Discrimination an How Does it Work?

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Larry, as usual Steve has done a masterful job of explaining the issues involved.  As he stated, the purpose of compressing high conductivity targets into a very narrow band at the high end of the scale  is to allow for a much wider spread on the lower end of the scale. Doing so helps to better separate and identify varying levels of soil mineralization, Hot Rocks, and smaller ferrous and non-ferrous targets. A target that registers at the high end of the scale, 70's or 80's, etc. is virtually guaranteed to be non-ferrous. In the goldfields those targets ALWAYS get dug. However, low-end numbers like 99, 00, 0, 01, 02 tend to be hot ground or hot rocks. Actual metal read higher. But not always. In really hot soil even sub-grainers can read 00. Remember, any form of target ID or discrimination is merely a tool. Wisely used, it saves time. Best wishes for your success with your 24k.

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Thanks. But i need to correct my comment. Substitute "99" for "95". "99" is the "wrap around" number for certain types. of hot rocks. 00 and 99 are almost the same target zone.

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On 2/6/2020 at 12:27 PM, LarryD said:

I recently purchased the Goldmaster 24k. In preparation for my first outing I made a test bed of different materials in my back yard. I also printed of the Conductive Order of Metals which was set up based on the Whites Spectrum XLT.

So my test bed consisted of a nail, pulltab, penny, nickle, dime, quarter, gold ring. After setting up my detector based on Whites quick start guide I did my testing. Here are the visual target id results. I wanted to compare them to the Conductive Order of Metals

GMT 24k reading.                        nail 39   pulltab 91  penny 95  nickle 89  dime 97. quarter 98  gold wedding ring 94

Conductive Order of Metals       nail 0     pulltab 35  penny 56   nickle 28  dime 70  quarter 82  gold wedding ring 40

As you can not even close. So am I wrong in thinking the GMT 24k should follow the Conductive Order of Metals listing? Is there some other listing I should be looking at or is there no corelation at all? Thanks for any help.

 

20180925_105548.jpg

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