Voodoo Main Discussion

[surfdetector]

The only concentric shell i could find was all closed in and one hole in the center and i wanted a open one like in the picture ill have to figure out how to hunt him down on here lol

He makes them. All you need to do is contact him.

[SilverSurfer17]

Yeah i just looked him up then realized who he was after seeing his pic by any chance do you know anywhere that sells the plastic piece that goes in the poles for the coils ive been keeping a eye out at detector sites and haven't come by one ?

[SilverSurfer17]

Where the coil mounts to the pole is called the yoke ? https://www.seriousdetecting.com/pro...tor-8013-0044/

[SilverSurfer17]

When you enter radius into the cc do you minus the thickness of the coil like if the radius is 4 inches for a 8 inch coil do you use 4 inches or like 3 1/2 in the cc to account for the thickness of the coil because i noticed George used a 3 inch for his 7 inch instead of 3 1/2 diameter or was it so it fit correctly in the shell he had ?

[dfbowers]

He makes them. All you need to do is contact him.

I dont think Hayes is in business anymore.
I can send 10 inch shells to anyone who might want one. I have not made any covers yet and mine are meant to be epoxy filled as they are only 1/16 ABS. Tabs are 17mm made for Whites lower rods. If there is enough interest I can make an 8 inch Black or white.
One essential thing I ran into is spool is needed for the RX as it becomes a handful to wind a bucking coil without one. I may be able to provide parts for a spool too..

[SilverSurfer17]

Yeah a 10 inch is to big i stretched it already from 7 because i know 10 is suppose to be a perfect size but for where im gonna be using it thats to big and yes ive seen some spools made out of foam can these Coils be covered with carbon fiber or does the carbon affect the coil ?

[dfbowers]

Yeah a 10 inch is to big i stretched it already from 7 because i know 10 is suppose to be a perfect size but for where im gonna be using it thats to big and yes ive seen some spools made out of foam can these Coils be covered with carbon fiber or does the carbon affect the coil ?

10 inch makes pinpointing tough.. plus you get to the point of diminishing returns on size vs depth and weight. I Donno about carbon fiber but since its conductive there might be trouble.
Also the open center coil introduces a new challenge in that you have limited area to make a fine tuning loop at the end of the bucking coil. I have been just doubling back through one of the spokes when the coil gets to a null.

[SilverSurfer17]

I didn't know carbon fiber was conductive i know it uses some kind of 2 part epoxy ill have to check it i was going to make a form get it all tuned then wrap it with brown paper bag painted with that guitar paint then wrap something to insulate it then wrap it in carbon fiber then epoxy it all in place where its tuned i can make a extra leg for extra bucking coil wires im still kinda unsure on the bucking coil if thats a separate coil or is that extended of the outer loop i think its outer and its using the bucking coil to help the inner pickup the signal the diagram im looking at uses three different colors for coils it also says keep extra wire because you will have to add a few turns to the inner coil because the bucking coil will change it after the bucking coil is added

[MartinB]

Yes . 3 superimposed coils Rx- / Tx / Rx +. I made one for the test. But not had good functioning. failed to make the Rx "invisible" on the oscilloscope. If anyone here knows this method, I'm very happy if he explains how to do it, or what I've done wrong ... but for voodoo it would be a good idea.

Could you post a photograph of what you are seeing on your scope?

[dfbowers]

I didn't know carbon fiber was conductive i know it uses some kind of 2 part epoxy ill have to check it i was going to make a form get it all tuned then wrap it with brown paper bag painted with that guitar paint then wrap something to insulate it then wrap it in carbon fiber then epoxy it all in place where its tuned i can make a extra leg for extra bucking coil wires im still kinda unsure on the bucking coil if thats a separate coil or is that extended of the outer loop i think its outer and its using the bucking coil to help the inner pickup the signal the diagram im looking at uses three different colors for coils it also says keep extra wire because you will have to add a few turns to the inner coil because the bucking coil will change it after the bucking coil is added

Carbon fiber is bad news for things like RC drones as it can block RF from the antennas. I don't know about detector shells but it wouldn't be a choice of mine.
The bucking coil is not a big deal as you only need 5 - 6 turns to cancel out the main coil. Just continue winding the end of the TX wire the opposite direction around the RX coil.
Thing is, you will almost always end up with some fraction of a turn at the end and you need to stop when you hit the null of the coil or it will be no good. I usually double back the other direction against the TX coil when I get the null, or leave a small loop of wire at the end, under the tabs area and move it around and glue it down to do the fine tuning.

[SilverSurfer17]

Yeah maybe ill use fiberglass then i hate working with it but i don't want anything hindering it and ill tune it then back it up then glue it down from the posts I'm reading on the coil i think it said 11 loops but I'm gonna leave lots of extra im not doing it exactly how he did his anyway so im sure its all gonna be different i have a lot of 30 gauge wire from making Tesla coils so im gonna make a bunch of coils and mess with around with different shapes and spreading the wires around to figure out what does what

[6666]

Yes . 3 superimposed coils Rx- / Tx / Rx +. I made one for the test. But not had good functioning. failed to make the Rx "invisible" on the oscilloscope. If anyone here knows this method, I'm very happy if he explains how to do it, or what I've done wrong ... but for voodoo it would be a good idea.

Hi lamoiz, thanks reply, would your pancake coil also be known as coaxial coil , some years ago Aziz did some work on coaxial coils he called it his "top hat coil", been looking for his posts about it, but I think he found he had to separate the coil windings by 80-90mm in height.

[6666]

I haven't tried such coil so far.
Balancing seems too complicated for me.
Even "CC" coil is too complicated to balance... in these conditions.
Truth is; the other day i prepared former for CC coil.
I had enclosure from before, i only 3D printed former for RX and former for bucking coil.
Enclosure is big enough to fit 25-27cm TX coil.
And dimensions of RX and bucking former are on the pics:

[ATTACH]54243[/ATTACH]
[ATTACH]54244[/ATTACH]
[ATTACH]54245[/ATTACH]
[ATTACH]54246[/ATTACH]
[ATTACH]54247[/ATTACH]
[ATTACH]54248[/ATTACH]

Have you considered a DSR coil ? they are IB and very easy to make.

[ivconic]

I'll stay with Omega coil by now.

[surfdetector]

Have you considered a DSR coil ? they are IB and very easy to make.

@6666 I did a search for DSR coil and did not find anything. I would like to learn about these if you could point me towards some information. Thanks.