Voodoo Main Discussion

[scrungy_doolittle]

PICS are good processors, though I only really like the PIC24 family. I hate most of them, whoever heard of a 12 bit address and a 6 bit byte.
PICS do program pretty easily.

[Bartmanzl]

Voodoo is more tolerate of non-homogeneous mineralized ground than a VLF detector, but (like a VLF) the DISC channel is still affected. If you don't need ferrous/non-ferrous discrimination, then the Mirage may be a better bet as it includes ground balancing.
It would be possible to modify Voodoo to include ground balancing for situations where the ground is heavily mineralized, but it doesn't have that capability at the moment. Voodoo is designed for use on the beach and inland, but not for the ghastly ground conditions found in Australia.

Ok, thanks for that
Regards
Bart

[MartyJ1963]

Thanks George,,,,No probs. I built Svens original then the last revision he did, then Elliots version. I thought I was missing something when you mentioned it had 'Ground balance',,Lol. I've stll got my coil to build yet for my Voodoo but got a lot of things going on at the moment. I thought I'd practise at bettering my building/Tuning skills on VLF coils for my TGSL and IDX first before attempting the Voodoo. All my Home built VLF's work but I haven't yet conquered building a field worthy working coil for them yet! Lol,,but it's on my bucket list to eventually get right as well as properly learn my Oscilloscope! Thanks for the info, Rgeards, Marty.

[Qiaozhi]

Hiya George, Regarding with what you mentioned about the Mirage, which version of it includes Ground balancing? Or is it every version? I never knew this and have built 3 different versions of the Mirage. Thanks, Regards, Marty.

Hi Marty,

For some reason I've always assumed the Mirage included ground balance, but it appears that I was wrong.
Perhaps an alternative would be to look at waltr's modified HH2 -> https://www.geotech1.com/forums/show...ake-on-the-HH2

[MartyJ1963]

Hiya George, Regarding with what you mentioned about the Mirage, which version of it includes Ground balancing? Or is it every version? I never knew this and have built 3 different versions of the Mirage. Thanks, Regards, Marty.

[Qiaozhi]

Newbie question, Just found this amazing site and project has anyone tried detecting with the Voodoo on black sand/Ironsand beaches? I've recently built a Arduino Nano PI detector and it works OK, but it has no chance on the sand around here that has been mined for years for its Iron content, also I'd prefer to build one than spend $$$ buying one.....Thanks Bart

Voodoo is more tolerate of non-homogeneous mineralized ground than a VLF detector, but (like a VLF) the DISC channel is still affected. If you don't need ferrous/non-ferrous discrimination, then the Mirage may be a better bet as it includes ground balancing.
It would be possible to modify Voodoo to include ground balancing for situations where the ground is heavily mineralized, but it doesn't have that capability at the moment. Voodoo is designed for use on the beach and inland, but not for the ghastly ground conditions found in Australia.

[dfbowers]

I am using a home built concentric. Around 7mH for the RX coil and 300uH for the TX. Same coil I used for my own Hybrid, where TX and RX sensitivity are about the same.

[Bartmanzl]

Newbie question, Just found this amazing site and project has anyone tried detecting with the Voodoo on black sand/Ironsand beaches? I've recently built a Arduino Nano PI detector and it works OK, but it has no chance on the sand around here that has been mined for years for its Iron content, also I'd prefer to build one than spend $$$ buying one.....Thanks Bart

[MartinB]

I used the Fisher F75 coil for my project and I noticed the same thing.

Probably will not bother buying the coil for a while.

[surfdetector]

Hi Don
Not worked on Voodoo for a while, but during testing I did notice a drop off in sensitivity in hybrid mode; I put this down to the coil I was using (Minelab). Considered buying Fischer F2 coil to see if it makes a difference. What coil are you using?

I used the Fisher F75 coil for my project and I noticed the same thing.

[MartinB]

Question for builders that have completed their VooDoo projects. I'm trying to determine what is normal for this project.
With my build, in PI mode, it is very sensitive and the threshold can be adjusted down into the noise level. I have been running my threshold setting between 10 - 15 to keep it quiet.
This is not true with the hybrid mode on my build. I can adjust the threshold down to "0" and it's still stable. Is this what I should expect??

Also, hybrid mode is not as sensitive as the PI mode on mine.
I bumped up the preamp gain on the disc section and it did not make a significant difference. I also played around with the offset of the disc preamps and all that did was mess with the ability to disc. Neither one of these changes made a difference with the threshold level.

Thanks in advance!
Don..

Hi Don
Not worked on Voodoo for a while, but during testing I did notice a drop off in sensitivity in hybrid mode; I put this down to the coil I was using (Minelab). Considered buying Fischer F2 coil to see if it makes a difference. What coil are you using?

[dfbowers]

This may be an inescapable consequence of adding discrimination, in the same way as adding ground balance to a PI detector reduces the depth.
I have also tried boosting the DISC preamp gain with no significant difference, and adjusting the DISC preamp offsets.

At the moment I'm working on a different project, but may revisit Voodoo again some time in the future.

Thanks George!

Don..

[Qiaozhi]

Question for builders that have completed their VooDoo projects. I'm trying to determine what is normal for this project.
With my build, in PI mode, it is very sensitive and the threshold can be adjusted down into the noise level. I have been running my threshold setting between 10 - 15 to keep it quiet.
This is not true with the hybrid mode on my build. I can adjust the threshold down to "0" and it's still stable. Is this what I should expect??

Also, hybrid mode is not as sensitive as the PI mode on mine.
I bumped up the preamp gain on the disc section and it did not make a significant difference. I also played around with the offset of the disc preamps and all that did was mess with the ability to disc. Neither one of these changes made a difference with the threshold level.

Thanks in advance!
Don..

This may be an inescapable consequence of adding discrimination, in the same way as adding ground balance to a PI detector reduces the depth.
I have also tried boosting the DISC preamp gain with no significant difference, and adjusting the DISC preamp offsets.

At the moment I'm working on a different project, but may revisit Voodoo again some time in the future.

[dfbowers]

Question for builders that have completed their VooDoo projects. I'm trying to determine what is normal for this project.
With my build, in PI mode, it is very sensitive and the threshold can be adjusted down into the noise level. I have been running my threshold setting between 10 - 15 to keep it quiet.
This is not true with the hybrid mode on my build. I can adjust the threshold down to "0" and it's still stable. Is this what I should expect??

Also, hybrid mode is not as sensitive as the PI mode on mine.
I bumped up the preamp gain on the disc section and it did not make a significant difference. I also played around with the offset of the disc preamps and all that did was mess with the ability to disc. Neither one of these changes made a difference with the threshold level.

Thanks in advance!
Don..

[sinclairuser]

Good morning everyone on the forum, I'm here h? some time, and like some others I decided to try to build the voodoo metal detector, I don't come here to try to take advantage of anyone, I bought George's book because I believed from the beginning in the potential of this detector and I need a pi accessible, I wish I could count on someone who can help me, I did everything as George recommended, I followed all the steps from the beginning and my plate mounted I have 15.0 v on the panel, if anyone here can help me help i'll make a little video tomorrow and I will post it, thanks for all your attention (and I apologize for the spelling mistakes this is a google translation

if you have followed exactly and its not running double check every thing, its usually something simple.
if you cant find a fault, check your components make sure you have no fake ic's, regulators etc, during this chip shortage fake stuff is a real problem.
after that take clear pictures outside in daylight of both sides of your board, the forum will look them over.
a fresh pair of eyes can sometimes find problems.
hope this helps.