Voodoo Main Discussion

[dfbowers]

Great news! What resistance did you chose for graphite shield and how did you positioned the drain wire in this type of coil?

I tried some generic "guitar shielding paint" that is pretty thick and coated the inside of the shell and masked off a small gap at one end. Turns out to be about 1 -2K per square. I just followed both coil channels most of the way around. The wire is held in place by the thick paint. Then a partial potting compound fill, then another layer of paint with another drain wire, then a complete second fill. It was probably the most labor intensive coil I have ever made. Seems to control the capacitance of my hand OK. I wasn't sure if the graphite paint would allow the potting compound to stick but apparently its just fine after setting up.
Wet grass will be the ultimate test! Not sure about the EMI control yet. There was some discussion of this method on the forum years ago and it just stuck in my head. Seems to be the way that the Tesoro and XP Deus coils are shielded too.

Here is a shorted link to the paint that I used:

https://tinyurl.com/y279v53b

[Mdtoday]

No Problems, I will post the project files once completed and tested.
I am going to order the REV -C Voodoo PCBs this morning.
Was not planning on going fully into George's project just yet as I am working with KingJL on his ADuM BP TX design, however, I have a little bit of a window now so will do what I can on the porting side but really would like to test on hardware.
My problem is I have a workshop full of SMD parts and only a handful of THD, so have to purchase most parts too.

cheers

Finally, I have delivery of all components, so will get on with building, testing and porting some code to XC8 compiler.
Will post code once tested.

Cheers

Mdtoday

[SilverSurfer17]

I saw the post on the three different types of cable to use ill have to order mine soon i was wondering anyone know what Minelab uses thanks or can narrow it down to whats best to use

[SilverSurfer17]

From what ive read on Google it says rg58au multiple strands but id trust what you guys say if there is something better

[dfbowers]

For those who still want to make pcb; this is by now the latest version:

I fixed a few minor things on the above schematic. Nothing major. Just what I am using on my current protoboard.
R54 - 10K
R24 - Deleted
R47 - 1K
C22 - 1uF BP
Don.

[dfbowers]

Since I got the modified Surf PI boxed up. Here is how it works. It’s not a depth monster.. maybe 8” on coins but that’s just the circuit that I picked for the experiment. The disc add on is actually more sensitive than the PI itself.. not sure what the results will be at depth yet. Anyway, if anyone has a video of their VooDoo working I would love to see it for reference.
Don..
https://youtu.be/L613UOxhBdw

[6666]

Since I got the modified Surf PI boxed up. Here is how it works. It’s not a depth monster.. maybe 8” on coins but that’s just the circuit that I picked for the experiment. The disc add on is actually more sensitive than the PI itself.. not sure what the results will be at depth yet. Anyway, if anyone has a video of their VooDoo working I would love to see it for reference.
Don..
https://youtu.be/L613UOxhBdw

Thanks Don, but having trouble seeing the meter movement, bit too far away, is that your home-made coil ?

[dfbowers]

Thanks Don, but having trouble seeing the meter movement, bit too far away, is that your home-made coil ?

Sorry, Video is so crappy. 480P.. I can see it on my mobile device but the resolution is not that good on my laptop. Yes, home made coil.

[SilverSurfer17]

Well that sucks book was suppose to be delivered by usps but it didn't come today like it was suppose to im so mixed up on what type of cable is best ive read like 5 different things from rg58a/u cable to mogami dual rca to ubs cable to microphone cable and also to make it as short as possible for a faster coil

[6666]

Sorry, Video is so crappy. 480P.. I can see it on my mobile device but the resolution is not that good on my laptop. Yes, home made coil.

Thats ok, just needs the camera to be bit closer to meter, when I go full screen on my laptop the video washes out just a touch too much on meter
does the meter have to be 100mA

[Qiaozhi]

Well that sucks book was suppose to be delivered by usps but it didn't come today like it was suppose to im so mixed up on what type of cable is best ive read like 5 different things from rg58a/u cable to mogami dual rca to ubs cable to microphone cable and also to make it as short as possible for a faster coil

Does Amazon not use their own delivery people in the U.S.?

[6666]

Does Amazon not use their own delivery people in the U.S.?

Here in Australia, international shipments like books get dumped on the Government Post Office to deliver.
Even thou I ordered my book via Amazon Australia, and paid for express delivery, it was eventually printed and posted from the US
and like I said dumped on the Post Office to deliver which all adds to the time.
Don't believe everything Amazon writes about themselves is true, they suck.

[waltr]

Does Amazon not use their own delivery people in the U.S.?

Only if you live close to an Amazon distribution center.

USPS (Postal Service) has been extremely slow on deliveries for the past 8 months. Even first class mail can take an extra 3-4 weeks.

[KingJL]

Does Amazon not use their own delivery people in the U.S.?

Yes and no! Not being a smart***, but that is the case depending on your location.

[Qiaozhi]

Interesting ...
In the UK I have often ordered something on Amazon one evening, and had it delivered the next day. Or maybe that's only because I have Amazon Prime.