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Hi WS, I have knocked up a quick 17x9 coil, its a monster, but looks promising.
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If you will use it on Surf PI make R2(near NE555) 5k instead of 3.3k for longer impulse because to pump same magnetic field with bigger coil area you need more power to the impulse.Originally posted by 6666 View Post
My dimensions was: inside 7.5" x 15" outside 9.5" x 17" so there is 1" for the winding and fiberglass.
Winding is almost flat spiral 9 layers 2 turns each = 18 turns total. AWG24 Teflon insulated silver plated stranded 19 strands wire = 65 ft.
So you will cover 100% of area and get all that $2 and $1 Aussie coins!!!
I have found $200AU coins here in Honolulu already. (But even more fun to find Japan coins like 500 Yen (equal $5-6US))
I wish US will have such valuable coins. I am tired to dig one penny all the time.
Good luck!!!Comment
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I have managed to keep my DD coils very light and stiff but I must admit that you take things to a whole new level with your coil! I can see where that would be just the ticket for covering sand at the beach but would be a nightmare in a cornfield. Could you share some details on how you built it?Originally posted by Waikiki_Sweep View Post
Thanks!
DonComment
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Yes, sure, I have made it for salt water. Problem was to make something hydrodynamically right to let it move in water. For cornfields a lot of perfect VLF detectors are created also moving something in air is not a problem.Originally posted by dfbowers View Post
I am pressing all the staff from fiberglass than sharpening it with sandpaper to keep all edges sharp to let it move in water easily. Biggest problem is wear up a coil in time. Sure any coil cover will slow it down so thin coil loosing that fiberglass layer by layer and require regular restoring of bottom side with new fiberglass layers. Also I am using marine epoxy resin based fiberglass because polyester fiberglass is too hydrophilic, sucking moisture and conducting electricity than. Coil has fixed angle to the stem because any bolts or fixation stuff will create drag in water. Stem is flat and sharpened too. Cable hidden inside stem because cable makes significant drag in water.
Once you will start thinking how to reduce drag in water you will see more ideas. Drag in water depends on shape and speed of object.
For example far end of coil has higher speed in water when you sweeping coil.
Even small plastic bolt will create drag you can feel if placed on the far end.
Anything closer to far end of coil has to be sharper, lighter, thinner.
All bulky and heavy items like electronic box, batteries, ... you have to move back where they will have lower speed in water.Comment
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Hi, my name is stefan. I?m new to this forum. I think this is the right thread to post my question.
I want to buy a cheap beginner "coin shooter" without LCD for my 13 year old daughter. I have searched the internet and this forum for a while and i think the gc-1023 or other brandname of this model could be the one. i know this is a cheap chinese machine, but it seems that this is one of the few ones that work. we search on dry, not to much mieralised soil.
Now my question. which coil should i take. ther is the standard 8" than a g25 which seems to be a 10" and i have heard of 12". the 10" looks so flimsy.
thanks for you for answering meComment
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if you really love your daughter you will not buy chinese crap for her.Comment
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If you buy that detector, I expect you will be very disappointed.
My advice would be to buy a detector like a secondhand Garrett Ace 150, rather than something new and cheap from China.Comment
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we already have one chinese 'calibrating' thread new. enough guys. please no more same matters.
yes, here are gurus but we are not able to help you all. CHINESES DO NOT BRING SCHEMATICS AND DESCRIPTIONS OF THEIR MODS TO US. https://www.geotech1.com/forums/show...orrectly/page3Comment
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thank you for your quick reply. ok i will search for something better used.Comment
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ACE250Comment
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