Voodoo Main Discussion

[godigit1]

Hi Marty,
I was short time to post this morning but if there is anything you want to know about construction method let me know.
I will say having the bucking coil wound around the bobbin in a flat manner made it super easy to null the coil by removing wraps.
Be Well

[6666]

Hi Marty,
I was short time to post this morning but if there is anything you want to know about construction method let me know.
I will say having the bucking coil wound around the bobbin in a flat manner made it super easy to null the coil by removing wraps.
Be Well

Interesting will have to study it.

[MartyJ1963]

@Godigit,,,,Thanks for your reply. It'll be great if you could post your construction methods of the particular 'Vertical stack' coil,,I'm really interested in having a go at this coil. I can see that I will be making a lot of different variations of coils for this particular project with the Voodoo being able to accept so many different inductances,,,really can't wait to get started on the build to actually be able to test all the coils I have planned to build already. I've never built this Vertical stack version so I'm looking forward to your construction guidance and actually building something different to test with the Voodoo. I've been spending the last few evenings learning how to use the software called 'Techsmith Camtasia' so I can incorporate my Voodoo build notes/experiments/coil builds and video logs into an actual full video log. Still playing about with it though at the moment but by the time I start building and taking notes, Photos, vids etc I should have some material to have a go putting it all tgether in one video. Thanks for taking the time to help us out with the construction details,,very kind of you. You stay safe and well too Godigit,,Regards, Marty

[godigit1]

Hi 6666 ,Marty.
Ill put something together comprehensive. I've taken Photos along the way.
I don't think anyone has made this coil that I know of. I've been playing with planar coils and wanted to try verticle stacks .
I remember way back Carl saying they had some advantages seemed like a good time to try as construction favors a concentric coils.

Here is the calculator I used for the stacked coil.
http://electronbunker.ca/eb/InductanceCalcML.html

[MartyJ1963]

Thanks Godigit,,Looking forward to the guide/photos etc. Regards, Marty.

[surfdetector]

As I wait for my Voodoo pcb to arrive, I decided to do a quick video on my YouTube channel on how to use a PicKit3 to load the Hex file onto the PIC. Obviously this is meant to guide people who may not be familiar with the process.
https://youtu.be/O9V8fmQWXe4

[MartyJ1963]

Hi Alec,,,I came across your new video a couple of hours ago on you tube,,,,Great video on programming the PIC and very well put together,,Nice one! Thanks, Marty

[godigit1]

Hi Marty.
Here is some further info on the test coil I wouldn't call it a guide but should give you some food for thought.

First the forms,
I used embroidery hoops to make the bobbins they come in round and oval.
I used a 4 inch and a 8 inch and super glued 1/8 inch foam board to each side to make the bobbin's. Most are about a half inch thick.
you can also use them for coil shells if you wanted.
In this pic are a couple different ones the one standing up is cut in half to show you could use them for a thinner bobbin if you wanted.



The Rx coil is built first, always add extra wraps so you can adjust it to your desired inductance by removing wraps at the end.
I had intended to make the rx coil a verticle and started out that way but ended up just doing a spaced bundle kinda.
I wrapped 20 wraps then wrapped that with a layer of tape then 30 , tape 20, tape 30 for a total of 90 wraps.
I removed 10 to tune it to 2nH so 80 wraps 30 awg magnet wire.
Then you want to wrap the coil in one last layer of tape this time it needs to be double sided to hold the bucking coil in place.
The Scotch in the pictures is the only one I've had good luck with.

Next is the bucking coil,
I wrapped it from the top to bottom with 9 wraps it was figured for 7
I eyeballed the wire spacing and the double sided tape holds it in place so you do not need a spacer. Its a test coil a final production would be done a bit better.

Close up of the bucking coil.


Then Attached the rx and bucking coil to the Tx form.
I used double sided tape so I could adjust it if I wanted.
Cut a slot through the foam board on the Tx where you want it and cut a grove in the bobbin to inset the Tx wire.


Now wrap the base of the Tx spool with double sided tape and you can start the first layer.
I went 15 wraps keeping a space between the wires then another layer of double sided tape and 15 more wraps and a third layer of tape and 10 wraps.
for 40 wraps . I way over did it.
At 40 wraps though for info it was exactly 1nH inductance. I removed 13 wraps for a inductance of 385uh.

TX stack


Here is a top view if the coil you can see where I cut the slot to start the tx wind.



Now to null the coil you just remove a couple wraps and get it close as you can but do the final null in the shell so its attached to the cable and everything can be locked down.

Keep in mind this coil has never been tested I need to build a regular bundle with the same spec to compare to just to have a base line.

Looking forward to your video production good luck with all that.
Now to watch surfs vid and pass out.

[6666]

Thanks GD, but first attachment is invalid.

[godigit1]

Thanks for getting to me so fast.
I was able to fix it and your welcome hope it helps.
Be Well

[MartyJ1963]

Thanks Godigit. Great of you to take the time to put together the guide to building your coil,,and thanks for the pics. I will be having a go at this coil along with the others I've made templates for,,,,I can see I'm going to be very busy this Winter with all the coils builds,,but I'm totally looking forward to it! Thanks again and stay safe, Marty.

[surfdetector]

George,

Referencing Fig 6-7 of your book, the Fisher F75 to Voodoo Adapter cable:

Did you actually insert the 33nF capacitor that is between pins 1 and 2 into the cable assembly? Thanks.

[MartyJ1963]

Hiya George,,,Can you tell me what wire/cable you used to that connects to the LCD and Menu buttons please? (FIG 44: Page 36). Trying to find some wire and some type of connectors for when I get to this step of building. Thanks, Marty.

[Qiaozhi]

George,

Referencing Fig 6-7 of your book, the Fisher F75 to Voodoo Adapter cable:

Did you actually insert the 33nF capacitor that is between pins 1 and 2 into the cable assembly? Thanks.

Fig. 3-15 shows that the tuning capacitor is recommended to be fitted inside the coil plug.
In the case of the Fisher F75 adapter cable (Fig. 6-7) you have a choice. Either fit the 33nF capacitor inside the plug (as before), or the socket. Personally I would put it in the plug.

[Qiaozhi]

Hiya George,,,Can you tell me what wire/cable you used to that connects to the LCD and Menu buttons please? (FIG 44: Page 36). Trying to find some wire and some type of connectors for when I get to this step of building. Thanks, Marty.

This is the actual reel of cable that I bought -> https://www.ebay.co.uk/itm/13-Core-M...ar=&hash=item0
but it is no longer available.
The bottom line is that you need 14 individual wires to connect the LCD and menu buttons if the LCD has a backlight, and 13 wires if the LCD does not have one.
I had to do a lot of searching to find a suitable 13-core cable. An alternative would be to use two multi-core cables. It does not need to be shielded.