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OK so apparently I don't have a good understanding of what type of metal my detector and find.  I've only had my SDC for a week or so and I'm new to metal detecting.  I put two of girlfriend's earrings on the surface of some soil and here are the results:

  • White gold (or platinum I'm not totally sure) earring:  SDC doesn't sound off at all
  • 14K gold earring:  SDC produces a very faint sound

Again the earrings were on the surface of the soil.  My detector is finding things like bullets, nails, aluminum foil, etc just fine.  I also buried an old gold plated tooth about 6 to 8 inches down and the SDC found that too.

So is there something special about the earrings?

Thanks!

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The SDC 2300 should have no problem on the 14K gold earring. If you are not sure about the composition of the silver/platinum/who knows earring the SDC may feel the same way. 

Where did you do your earring test?  If you were in an area with high EMI, like in just about any backyard in the Denver area, the resulting rollercoaster threshold tone may have have completely obliterated the target tone. I have hit gold, lead and aluminum in the 2 mm in diameter size range easily with my SDC 2300, but only in places where the threshold was very steady with the occasional blip. That definitely could not happen in my backyard in SW Denver. I can't even turn it on without it sounding like an ambulance and that is on sensitivity setting 1 or 2.

 

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I actually live in Parker Colorado and I did the test in an open field behind my house.  I'm well away from my house and any above ground power lines.  I don't think the open field has any underground power lines.  I did a noise cancel/ground balance and the threshold actually isn't too noisy.

I used a multimeter to make sure the white gold earring it metal.  It's strange that metal trash close to the surface makes the detector scream but the gold earring is very faint.  And the white gold one makes no sound!  It seems like both earrings should make the detector scream.

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White gold is a worse conductor than pure gold or pure silver and therefore difficult to detect. Most detectors will not beep at all on a simple white gold single post earring. Also, broken circles, like a ring with a broken solder joint, are extremely hard to detect. If your earrings are open or if the connection is weak it will hurt the signal. A very high frequency VLF is best for targets like that.

https://www.detectorprospector.com/forums/topic/11003-equinox-tid-and-gold-rings/?do=findComment&comment=108331

 

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That thread is very interesting...

Yellow 14K gold is 58.30% Au  30%Ag   11.70%Cu

I don't know what karat the white gold earring is.  Looks like white gold is also mostly gold and silver but with other possible metals such as palladium, zinc, and platinum.

https://www.gold.org/about-gold/about-gold-jewellery

So 14K gold is a poor conductor.  Maybe the particular alloy of the white gold earring makes is even worse than 14K yellow gold.

From what you're saying Steve it sound like my detector is probably OK.  I had not heard about broken circles.  Each earring has a hinge and a latch so maybe that's and issue too.

Thanks

 

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I think your detector is fine. The broken ring thing has to do with eddy currents. Normally a solid ring creates the perfect path for eddy currents and creates a strong target. Break the ring, and now instead of one large eddy current you get numerous very small ones. See the last paragraph of page 2 and page 3 of this document, which shows why a ring detects better than a coin.

https://bodhi3.files.wordpress.com/2013/05/induction.pdf

Detecting a White Gold Single Post Earring

More On Single Post and Small Jewelry

Micro Jewelry Hunting Advice

 

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Welcome to the forum Bryan!!👍👍

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So, looks like your SDC is okay. If your threshold is fairly quiet and steady with no big rhythmic oscillations you don't have much EMI.

If you don't have any natural gold  for testing, try some really small lead 1 gram fishing sinkers, .177 caliber lead pellet gun pellets, .22 caliber bullets and shell casings, small but chunky aluminum, and  a US Jefferson nickel which is similar in weight and conductivity to a 4 to 5 gram gold nugget.

Welcome,

Jeff

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I did a quick test on some 14K gold earrings similar (though smaller) to yours. If I just put them on the ground I had a similar result, meaning I could pick them up but the signal was not as solid as I would expect from almost a gram of 14K gold. So, I did a hand sweep of the coil without the earrings and got a faint signal. When I did a sweep while holding the earring's closure really tight against the rest of the earring I got a really strong signal. So...........

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Good subject! I didn't know white gold was an issue?!   Is this universal for all detectors?? VLF, and PI??

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