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Tom, im not sure i grasp your meaning.

when two conductors have current flowing the same direction and are placed close together they form figure eight of sort as thier em field.

when that current is flowing in opposite directions the em field balloons in the middle making it look more like a diamond.

i theorize that this ballon effect may add to the depth the em field is capable of reaching.

if youre refering to the chart it represents a materials ability to tranfer voltages efficiently.

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Tom, if you were looking at my sketch it isnt the gratest. the solid lines on upper drawing represent the coil windings with arrows indicating current flow direction. the inset/lower drawing is an exagerated depiction of theorized em field of the center halves of the coil.

Hope that helps.

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If you take a look at an analog detectors meter readings, i believe they are grouped based on conductivity. I was referring to how it applies to a detector, as apposed to the theory of current flow.

When i saw the chart it reminded me of the chart in a little booklet called fisher intelligence put out by Tom Dankowski.

Sorry ,didn't mean to get off the topic of the thread!

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Subject for another thread but yes, alloys will often be of lower conductivity than pure metals. Gold alloys are dramatically less conductive than pure gold for instance. And on detectors size is every bit as important as conductivity. VDI numbers really only have meaning for repeatable items, like a dime, and even then only under favorable conditions.

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So is it the number of electrons or the electrons distance from the proton that is the conduction variable?

 

From what I understand it's the number of electrons that are free to move, and thus create the current. Metals such as Copper, Silver and Gold have increasingly larger and heavier atoms (with more electrons in them), But each has a free electron in it's outermost shell, which is why they are good conductors - this electron can be freed to create a current. However because of the way that electrons shells fill up, silver is the most conductive of the three, because its outer electron can better escape the pull of the nucleus (positive charge).

 

You could in theory make an extremely fine wire from gold, because it is so malleable (think how thin gold leaf is). That would help the weight issue, but the cost of doing so would probably be too high and the conductivity of gold is lower than copper anyway. You'd probably have more gold in your coil than you would ever find by using it haha!

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