Voodoo Main Discussion

[Orbit]

Do this detector hybrid vlf and pi like continuous mode hybrid or it can also work with a single coil ? If we use a concentric probe with two coils then it should work always as a hybrid am I right?

[Qiaozhi]

Do this detector hybrid vlf and pi like continuous mode hybrid or it can also work with a single coil ? If we use a concentric probe with two coils then it should work always as a hybrid am I right?

You can switch between a standard PI mode and a Hybrid mode. A concentric coil will work in both modes. If you fit a mono coil it will only work in PI mode.
This is all explained in the book.

[lamoiz]

As you see from Chapter 6, all the coils were of the concentric type except one. The exception was the Fisher F75 DD coil, which had a slight disadvantage when the detector was switched into PI mode.

but in disc mode (hybrid) the f75 was good or bad too?

[MartyJ1963]

Thanks guys,,,I already have that document but I will definitely give it a good 'Re-read' again. I hopefully want to start building on Friday, after my house repairs are out of the way. Thanks, Regards, Marty.

[MartyJ1963]

Hi all,,On the 'Battery charger' PCB, Am I able to use either a 1n4004 or 1n4007 diode in place of the 1n4001 please? Totally out of 4001's. Thanks, Marty

[lamoiz]

@Lamoiz,,,I don't think the Voodoo coil has a ' Bucking' coil. I believe it just consists of an outer loop, the TX, and the inner loop, which is just the RX. The TX Coil has a parallel Damping resistor and the RX Coil has a parallel Capacitor. Someone can correct me if I'm wrong or mistaken,,,Regards, Marty.

good evening Marty,
if there is a canceling coil, otherwise it will be impossible to null the rx coil. I have already made several concentric coils, the development is not easy, even with the calculation, trust me. the double d solution is easy to do, so is the omega. but if this is the only way to make a coil for the voodoo, then it will have to be done. however, I am going to do a 30cm omega and a super d with two rx. I don't think I will say anything more on the forum, because when I ask questions I have no answer .. so ..

[6666]

Hi all,,On the 'Battery charger' PCB, Am I able to use either a 1n4004 or 1n4007 diode in place of the 1n4001 please? Totally out of 4001's. Thanks, Marty

Hi Marty, YES.
The in4001 is only a 50 volt device where the 04 0r 07 are a higher voltage rated replacement, buy the 07 so you dont have to worry about it again

[MartyJ1963]

Hiya Lamoiz,,,Yes, I was wrong thinking there wasn't a Bucking coil but Qiaozhi corrected me. I still have to find out how to calculate the amount of turns needed for the bucking coil of the small coil I'd like to try first. I had some recent success making an Omega coil for my IGSL,,it works quite good but I'm still experimenting with it at the moment. Regards, Marty

[MartyJ1963]

@6666,,,,Thanks a lot. I thought I could but as always, it's safer to ask and make certain! I've plenty 1n4004 and 1n4007 so I'll use the 007. Thanks again, Regards, Marty.

[MartyJ1963]

Hiya Lamoiz,,,I used this template for my IGSL Coil but I expanded the drawing into a 8" size coil. It may be good for what you are wanting to try? Regards, Marty

[6666]

With this template you can make it any size.

[Qiaozhi]

but in disc mode (hybrid) the f75 was good or bad too?

The F75 coil performed well. See pages 70 and 71.

[Qiaozhi]

good evening Marty,
if there is a canceling coil, otherwise it will be impossible to null the rx coil. I have already made several concentric coils, the development is not easy, even with the calculation, trust me. the double d solution is easy to do, so is the omega. but if this is the only way to make a coil for the voodoo, then it will have to be done. however, I am going to do a 30cm omega and a super d with two rx. I don't think I will say anything more on the forum, because when I ask questions I have no answer .. so ..

You can try any type of induction balanced coil you desire: concentric, omega, DD, super D, etc. In theory they should all work, but some may be better than others. Personally, I opted to focus on the concentric type.

[Qiaozhi]

I don't think I will say anything more on the forum, because when I ask questions I have no answer .. so ..

I have answered your questions. Maybe you missed my answers, or you were expecting an instant reply. Sometimes it takes some time to receive a reply due to different time zones, so you have to be patient.

[lamoiz]

I have answered your questions. Maybe you missed my answers, or you were expecting an instant reply. Sometimes it takes some time to receive a reply due to different time zones, so you have to be patient.

thank you very much george. yes you answered all my questions, I thank you very much. sometimes I wonder if the French vocabulary is not badly translated by google .. but whatever, I build your project and I am happy to discuss with you.