Voodoo Main Discussion

[surfdetector]

thank you surf; you have very good results .. i am not at that on the omega. but since this morning I have been working on the super D, and I am slowly approaching what you get with the F75, with precision on the target. With the superD, the target is centered on the hybrid rx mode, as in pulse. This is really good. I am progressing well.

I look forward to seeing the results with the Super DD. The Voodoo is a great project that will have much more of interest to see.

[lamoiz]

Hi Lamoiz,
I am getting about 4.5" on a 3 gram 18k ring with standard default settings in PI mode and about 4" in Hybrid
I am getting about 6" on a 7 gram 14k ring with standard default settings in PI and Hybrid modes
The coil I am using is a Fisher F75
I conducted these readings inside my house as it is raining very hard here today so that must be taken into account as a factor.

I have yet to take my machine out to the beach as I am still waiting for a carbon fiber tube for a shaft. I prefer to do testing as part of a real hunt as opposed to using a ruler.

thank you surf; you have very good results .. i am not at that on the omega. but since this morning I have been working on the super D, and I am slowly approaching what you get with the F75, with precision on the target. With the superD, the target is centered on the hybrid rx mode, as in pulse. This is really good. I am progressing well.

[surfdetector]

this evening I made tests at different frequencies, here is a summary of the results on a Napoleon bronze coin. the best is around 10khz. I tested on the omega; rx a 5, 7.7; 10, 15.5, 22 khz,. for gold, I have not tested. I asked a friend in MP to do the test on the f75. I will now do the same tests on the Super D this weekend.

Hi Lamoiz,
I am getting about 4.5" on a 3 gram 18k ring with standard default settings in PI mode and about 4" in Hybrid
I am getting about 6" on a 7 gram 14k ring with standard default settings in PI and Hybrid modes
The coil I am using is a Fisher F75
I conducted these readings inside my house as it is raining very hard here today so that must be taken into account as a factor.

I have yet to take my machine out to the beach as I am still waiting for a carbon fiber tube for a shaft. I prefer to do testing as part of a real hunt as opposed to using a ruler.

[lamoiz]

Hi Lamoiz
Contacted a UK manufacturer of litz wire today who asked me some interesting questions which led to further research into litz wire.
You will see from the attached table that 0.2mm to 0.25mm diameter conductors are more suited to our purposes and designs
[ATTACH]53962[/ATTACH]

good information .thank you.

[Qiaozhi]

Hi George, do caps 15/18, 16/17 have to be matched ?
I am guessing not, thanks.

Probably not. I didn't bother and it worked fine.

[ivconic]

Thanks reply, do you have your Arduino UNO R3 set up so it can program attiny 12-13-15 ? if I could do that I would be happier.

No. I started late with Attiny85, recently actually. So i am not familiar with older models.
But this question makes me "google" the net and see what is the problem.
Small flash, no SRAM, no polling; makes those impossible to program in Cpp with IDE.
Only assembly. Old way. Probably Arduino ISP with fixed delay.
Avrdude maybe.
If i had one of those; i would probably try anything from the methods.
But with affordable Attiny 85 i don't see a reason even to mention those oldies.
Especially with appearance of cheap Digispark USB dongles.

[6666]

Hi George, do caps 15/18, 16/17 have to be matched ?
I am guessing not, thanks.

[MartinB]

Hi everyone. I made 3 rx coils for the omega. 1: 0.10mm, 2: 0.20, 3: 0.25mm all three have almost the same inductance value, only their resistance changes of course, .. for the moment, it is 0.25 mm which is the most sensitive to the target size. all resonate at 9.9, 10, and 10.2khz. Tomorrow I change the capacity, to resonate at other frequencies ..

Hi Lamoiz
Contacted a UK manufacturer of litz wire today who asked me some interesting questions which led to further research into litz wire.
You will see from the attached table that 0.2mm to 0.25mm diameter conductors are more suited to our purposes and designs

[MartinB]

https://www.ebay.fr/itm/50m-165-Litz...cAAOSwuHJbC-5- hong kong...
hi, i bought in this shop .. see if there is any 175/46 .

Thank you.
I will purchase from either Hong Kong or USA although this will delay the development of my coil.

[Qiaozhi]

most of the vlfs i have owned will not find small gold unless over 13khz, my tesoro right now is at 25khz, and i had a whites GM that was at 50khz, the whites could pick up sub gram at 2-3 inches in the Az soil here with black sands. That is with a 6x9 oval DD, dont know if this info helps or not, when voodoo in vlf mode does it go by khz, or is it a generic PI mode or actual vlf mode.

Have you not read the book?

[6666]

[ATTACH]53952[/ATTACH]

I have many more tools.
Probably several G-bytes of various software tools for AVRs.
I have all known Arduino development systems and boards (boxes and boxes fed up and piled up).
I have USBasp dongle ISP programmer. Also have AVRISP MKII programmer to, PDI option too.
Also i made several "bare bone" programmers.
Also i made "fuse doctor" board. Works like charm. Resets and puts all the fuses to default values at almost all known AVRs.
Usually i do know how to set the fuses in details. But sometimes i like to experiment with protection and not so rare case that i make mess with fuses and simply "brick" the mcu.
Than i pull up "fuse doctor" and "heal" the bricked one in a second.
AVRISP MKII usually i use for HV programming. I use Atmel Studio (usually latest version) to update firmware at MKII.
Later i can use AVRISP MKII with Atmel Studio drivers or also as well as with LIBUSB drivers for use with third party software.
And over the top; Arduino UNO R3 can be configured and wired up to serve as programmer for all AVR's you can imagine.
Most of the time i use Arduino IDE for Atmegas and Attinys.
For STM32xxxxx ARMs i use AVRISP MKII with Flip or some third party software, depends, from case to case.
Although lately i arranged setup to program STMs directly via Arduino IDE.
Lately i obtain Attiny85 with USB on it, small dongle. It's all in bootloader.
Etc.
AVRs are so easy, fun and joy to work with them.
There is great massive open source community where you can find answer on any possible qestion.
Also there are "zillion" of ready libraries from almost everything to work with Atmels.
Programming was never easier.
You can do it both ways; "regularly" through the Studios and through the third party tools.

Thanks reply, do you have your Arduino UNO R3 set up so it can program attiny 12-13-15 ? if I could do that I would be happier.

[lamoiz]

most of the vlfs i have owned will not find small gold unless over 13khz, my tesoro right now is at 25khz, and i had a whites GM that was at 50khz, the whites could pick up sub gram at 2-3 inches in the Az soil here with black sands. That is with a 6x9 oval DD, dont know if this info helps or not, when voodoo in vlf mode does it go by khz, or is it a generic PI mode or actual vlf mode.

it seems to me that the idea, the concept of voodoo, is to TRUE discrimination on a PI, and I think George did a great job, many thanks to this great man.

[6666]

hi surf, with the same settings and the same target, the 0.25 mm detected with a few cm more .. about 2 or 3 cm maximum, the worst is the 0.10mm.

Thanks

[Matt_Rowe]

this evening I made tests at different frequencies, here is a summary of the results on a Napoleon bronze coin. the best is around 10khz. I tested on the omega; rx a 5, 7.7; 10, 15.5, 22 khz,. for gold, I have not tested. I asked a friend in MP to do the test on the f75. I will now do the same tests on the Super D this weekend.

most of the vlfs i have owned will not find small gold unless over 13khz, my tesoro right now is at 25khz, and i had a whites GM that was at 50khz, the whites could pick up sub gram at 2-3 inches in the Az soil here with black sands. That is with a 6x9 oval DD, dont know if this info helps or not, when voodoo in vlf mode does it go by khz, or is it a generic PI mode or actual vlf mode.

[lamoiz]

this evening I made tests at different frequencies, here is a summary of the results on a Napoleon bronze coin. the best is around 10khz. I tested on the omega; rx a 5, 7.7; 10, 15.5, 22 khz,. for gold, I have not tested. I asked a friend in MP to do the test on the f75. I will now do the same tests on the Super D this weekend.