Voodoo Main Discussion

[lamoiz]

I will also study a super D type double rx coil, even in a reduced size version, just to see.

[lamoiz]

I also tried making an Omega coil (not included in the book) and it did not null very well.

you mean it's not good? but was it a commercial coil or a handmade one?

[MartyJ1963]

Thanks guys for the info. @SurfDetector, I scanned them too but it hasn't helped. My PCB's arrived today (Big thanks Andy!) so I'm just gathering all the revelant information before I start. @Qiaozhi, Could you let us know what the pinout numbering of 'PL9' is please on the Silk? Like I mentioned earlier I'm having difficulty reading some of the diagrams in the book even though I've scanned them to enlarge them. Also, now I've enlarged them the lines are really faded and I still can't read the component values etc,,and I've scanned to the highest resolution I can. Regards, Marty.

[Qiaozhi]

Thanks for that info, I was going to ask George the same question, pin 1 should be on silk mask, just to be clear.

I've added the LCD pinout information to post #1.

[Qiaozhi]

@Qiaozhi,,What are the pin assignment numberings for 'U4' please? The LCD I have has pins 16 and 15 at one end and then 1 to 14. Thanks, Marty

In the image you posted, pin 1 is on the right-hand side (next to the ref des U4) and pin 16 is on the left-hand side.

[6666]

Hi Marty,
I scanned page 26 in the book and enlarged the schematic. It looks like the LCD pins are sequential 1-16. To check orientation on the PCB, pin 4 of the LCD should have continuity to pin 38 of the PIC.

Thanks for that info, I was going to ask George the same question, pin 1 should be on silk mask, just to be clear.

[surfdetector]

@Qiaozhi,,What are the pin assignment numberings for 'U4' please? The LCD I have has pins 16 and 15 at one end and then 1 to 14. Thanks, Marty

Hi Marty,
I scanned page 26 in the book and enlarged the schematic. It looks like the LCD pins are sequential 1-16. To check orientation on the PCB, pin 4 of the LCD should have continuity to pin 38 of the PIC.

[Altair]

My book item is arrived from Amazon: at first looking it's well promising and educative publication!
Congratulation George for your hard work, I will read it with great interest.
Thank you very much for sharing your knowledge!

[MartyJ1963]

@Qiaozhi,,What are the pin assignment numberings for 'U4' please? The LCD I have has pins 16 and 15 at one end and then 1 to 14. Thanks, Marty

[Qiaozhi]

good evening George.
I am going to make a coil of 28cm diameter. I have already built a concentric coil for an IDX, 3 years ago, and the greatest difficulty was the nulling rx. I therefore ask myself the question: could we imagine an omega shape ?, which is much easier to position for rx coil ...
i will do PI / TX 0.5mh litz 175/46 and rx / disc 7mh 33nf 0.18mm freq 10.5khz. copper enameled wire.ratio 1/2.4 115mm inner loop.
Is my idea bad or on the right track ..? what do you think ?

I also tried making an Omega coil (not included in the book) and it did not null very well.

[lamoiz]

or an idea on the principle of super D coil ..?

[lamoiz]

good evening George.
I am going to make a coil of 28cm diameter. I have already built a concentric coil for an IDX, 3 years ago, and the greatest difficulty was the nulling rx. I therefore ask myself the question: could we imagine an omega shape ?, which is much easier to position for rx coil ...
i will do PI / TX 0.5mh litz 175/46 and rx / disc 7mh 33nf 0.18mm freq 10.5khz. copper enameled wire.ratio 1/2.4 115mm inner loop.
Is my idea bad or on the right track ..? what do you think ?

[kt315]

Hiya Ivconic,,,,Sorry to here you're having a long wait for your book to arrive. Hope it arrives soon. Looking forward to reading about what you think of the project. Regards, Marty.

i got at ebay selling, in View tracking field : Due to the coronavirus emergency, deliveries may be delayed.

[MartyJ1963]

Hiya Ivconic,,,,Sorry to here you're having a long wait for your book to arrive. Hope it arrives soon. Looking forward to reading about what you think of the project. Regards, Marty.

[MartyJ1963]

Hi Alec,,,Thanks for your reply. I know about the reference points described in the book but was just curious if there were any points to check and measure that may have not been mentioned. It'd be great to get a build file put together for this excellent project,,,I'm in my element with it and cant wait for my PCB to arrive to begin building. I had to order the FQT7N10LTF mosfets because I couldn't find any FQT7N10 or FQT7N10L but the datasheet for them gave the same specs,,hopefully they are!. I'll be taking my time building as I want to document it all in case I run into difficulties. I have 2 X PCB's on the way but wll only buld one to begin with and build the 2nd after experiments with the coils. I've made templates for 3 different coils (all with the same inductances based on an 8" tx and 3.75" rx) based on Georges 'Small coil' described in the book. I just have to make some temporary, make-shift 'Shells' for them to experiment with. I am half-way through building my new 'Oven/Vacuum former' too so by the time it's finished I should have a better idea on what my final sizes are for the coils that bring the best results. I'll probably start building from next Friday,,,If I can get all the house repairs finished that I mentioned to you. My partner, Claire, says 'No playing with my new toys till the works done'!!,,,Lol. Take care and stay safe over there in the U.S.A,,,Regards, Marty.