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Anyone tried star coil ie coil made up and then bent into lobes (32cm down to 23cm) i did it to get a larger coil into an 9.8 inch coil casing but now i am getting much better depth and sensitivity (perhaps a fluke but....) 
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That's maybe a great discovery. -
I contradict. By such a coil shape, the magnetic field is greatly weakened in my opinion.
Like the basket coil, this is a tinkering for the kindergarten.Comment
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Maybe the inductance of the original coil has been changed such that it is now more agreeable with circuit. Hence the illusion of better sensitivity.Comment
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i had see that but i do not remember where...
https://www.banggood.com/High-speed-...r_warehouse=CN
LOL!Comment
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Seems to suit the felezjoo just fine gained a couple of inches depth in air and is better on gold ring (it is the stock coil from our friend sinko1) so i don't know about kindergarten Andi68 but as Feynman said The test of all knowledge is experiment. Experiment is the sole judge of scientific “truth”Comment
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Certainly, test and report ......Comment
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I did.Comment
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I was lost in translation
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i translated and was lost
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I have tried all sorts of shapes for a slow PI (Barracuda) For depth and pinpointing nothing beats a circle. Which is what I expected. Did quite like the triangle. The sharp point should be good around rocks. Difficult to test as you have to readjust the damping resistor after each change of shape. Also you have to have the threshold exactly the same. I had to unplug the batteries as the threshold and on/of were combined.
I reserve the right to change my mind as a star was one shape I didn't try.Comment
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An elliptical shape, rectangular shape ....Comment
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Who's gonna be winding that?Originally posted by kt315 View Post
Only one guy I see in movie" Back to the future". "Doc"Comment
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Yep tried them all. Its easy to change shape with a bundle of wires tapped together. Watched a YouTube video where they changed a round coil to an ellipse and got more depth.Originally posted by Andi68 View Post
It was rubbish. Just changing the inductance to better match the damping resistor.
If they had kept the coil as a circle and changed the damping would have had the same result
Or removed a turn or two.Comment
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The star shaped coil reference posted by KT is interesting. It combines the best elements of basket type and flat spiral coil in that it's coverage of entire width of coil plus separation of windings, sort of hybrid.
But I won't be the one that attempts to make it. Looks like for masochistic person to make.Comment
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