Goldprospector
Junior Member
- Joined
- May 14, 2017
- Messages
- 44
Greetings one and all. Today I would like to clear up a common misconception.
Some metal detectorists think that certain coil frequencies are better than others for finding targets of a certain conductivity. For example, they might feel that to find gold, it is best to use a higher frequency, say around 18 kHz. They might also feel that there is a "best" frequency to use for any given conductivity. Nothing could be farther from the truth.
Let's take gold for example. What's the conductivity value of gold? 44, 2? Plug in your own value for the conductivity value of gold. That wont matter. Whatever the value of X is, this is the conductivity value of gold. That doesnt change. The only thing that changes is the size/weight of the gold.
A 45 KHz coil will only "see" very small, typically shallow gold nuggets. Even if honker size nuggets are below the very small nuggets.
A big 3 kHz coil will only "see" larger, deeper nuggets. It wont even see the very small nuggets that the 45 kHz coil can find.
Same metal, same conductivity value. The only thing that has changed is the size/weight of the nugget. Looking for very small nuggets/targets? Use a 45 kHz coil. Looking for honker size nuggets/targets? Use a (larger) 3 kHz coil. The metal itself has no correlation to any particular frequency. Same with any other target. It's all about the size/weight of the target.
If someone says, 18 kHz is the best frequency for finding gold, what they really mean is that 18 kHz is the best frequency for finding gold WEIGHING AROUND ONE GRAM. So they are not referring to the conductivity of gold, they are referring to the target weight.
Some metal detectorists think that certain coil frequencies are better than others for finding targets of a certain conductivity. For example, they might feel that to find gold, it is best to use a higher frequency, say around 18 kHz. They might also feel that there is a "best" frequency to use for any given conductivity. Nothing could be farther from the truth.
Let's take gold for example. What's the conductivity value of gold? 44, 2? Plug in your own value for the conductivity value of gold. That wont matter. Whatever the value of X is, this is the conductivity value of gold. That doesnt change. The only thing that changes is the size/weight of the gold.
A 45 KHz coil will only "see" very small, typically shallow gold nuggets. Even if honker size nuggets are below the very small nuggets.
A big 3 kHz coil will only "see" larger, deeper nuggets. It wont even see the very small nuggets that the 45 kHz coil can find.
Same metal, same conductivity value. The only thing that has changed is the size/weight of the nugget. Looking for very small nuggets/targets? Use a 45 kHz coil. Looking for honker size nuggets/targets? Use a (larger) 3 kHz coil. The metal itself has no correlation to any particular frequency. Same with any other target. It's all about the size/weight of the target.
If someone says, 18 kHz is the best frequency for finding gold, what they really mean is that 18 kHz is the best frequency for finding gold WEIGHING AROUND ONE GRAM. So they are not referring to the conductivity of gold, they are referring to the target weight.
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