Bipolar PI MD with GB and DD Coil

[Detectorist#1]

Interesting post Riss, but I don't see any benefit from it for the metal detecting community.

[Detectorist#1]

Hi Riss, your recent posts indicate that you have moved from the field of engineering to the field of philosophy.

[eduardo1979]

Hello Detectorist #1. I just had an idea and I wanted your opinion, since I see you have quite a bit of knowledge about electronics and a lot of experience with metal detectors. The question is this: Do you think that if the discrimination module of the MSPI detector designed by DFBowers were added to your Bipolar MD design, ferrous discrimination would work well? I'd like to take advantage of the advantages of your Bipolar PI detector, which has good ground balance and natural EFE cancellation, and add that ferrous discrimination module. This way, we could say we have a 100% hybrid detector. We could also take advantage of the concentric or DD coils available on the market, such as Detech, etc. I thought that combining two good technologies could be something interesting. What do you think about all this? Best regards.

[algan]

Hello, Detectorist#1, can you tell me, for example, what depth you achieved with your bipolar board and what size mono or dd antenna? If you have pictures from the oscilloscope, that would be nice too. Thank you.

[Detectorist#1]

Hello eduardo1979,
Yes, I have good knowledge in hardware electronics (60 years) but not so good experience with metal detectors. Under the impressions of the "MPS" project of DFBowers, I made my project "Hobby Hybrid MD1" (posted here in Feb. 2025). Unfortunately, my more detailed tests points that polarity of the RX signal of the discrimination channel of this project depends from orientation of the target. Also the name "Hobby Hybrid" is not correct. This is not hybrid detector. This is PI detector with two channels of treatment of the RX signals - during TX pulse and after TX pulse. Now, I think that some detector is hybrid only if this detector uses treatment of two types of signals - PI and sinus (or part of sinus) like Voodoo project. I don't know how sure this project discriminate Fe/nonFe. I noticed that my simple MD (pinpointer) with frequency measuring of simple LC oscillator also gives wrong signal Fe/nonFe depending of the orientation of the target. As conclusion - the problem with sure discrimination Fe/nonFe isn't simple!

[eduardo1979]

Thank you very much for answering my question and clarifying some doubts I had about this project. What if we combine the Voodoo detector technology with your bipolar detector? Do you think it could work? I know that the DFBowers detector is based on the Voodoo, and according to the claims and videos presented by DFBOWERS, it has achieved good results. My idea is to combine a half-bridge bipolar PI detector with a VLF-IB detector using a DD coil, as used in the DFBowers or Voodoo designs.

[pechkata]

Hello
The ground balance of PI detectors moves discrimination to nothingness...
This is very clearly seen in the operation of Hybrid detectors.
Everyone is working at the table...

[Detectorist#1]

Hello pechkata,
Do you have experience with Fe/nonFe discrimination of Voodoo project?

[ArchibaldSTM]

While you are here having empty talk, I have finished building Delta Pulse and am very pleased with the result. I will go to the field soon.

[Detectorist#1]

Hi ArchibaldSTM,
As Carl says, bench testing is only 5% of your work on the path to a useful MD.

[GeoMax]

While you are here having empty talk, I have finished building Delta Pulse and am very pleased with the result. I will go to the field soon.

Hello,

Did you build the standard DeltaPulse or modify the circuit? I built the standard DeltaPulse about 20 years ago, and yes, it was impressive.

[pechkata]

Hello pechkata,
Do you have experience with Fe/nonFe discrimination of Voodoo project?

Hello Detectorist#1
There is no earthly balance at Voodoo - everything works well

[Detectorist#1]

Hello pechkata,
Thanks for this information. My question was how reliable is the Fe/nonFe discrimination in the Voodoo project. Does this discrimination depend on the orientation of the target? It is clear - no GB feature - no reducing of of the sensitivity.

[Detectorist#1]

Hello pechkata,
Also it is very interesting for me what is performance of the Voodoo MD in mild and heavy soils. Do you have practice information for this with some distances and targets?

[pechkata]

Hello pechkata,
Also it is very interesting for me what is performance of the Voodoo MD in mild and heavy soils. Do you have practice information for this with some distances and targets?

Hello Detectorist#1
That's basically it.