Do "OO" coils work on Pulse Induction?

[Nova]

G'day Coil Magicians, I have read that coplanar but specifically "OO" coils are pretty much the best coils to reduce noise and improve depth over highly mineralised grounds like we have here in Australia, I know the Nexus company makes these things but i am not sure if they are designed for IB or PI, and the price they are asking well, if i can't get any takers i will probably delve into this coil making business myself.
Now: if it's possible to work on PI, and specifically for SD 2200d, i would like someone to make me one of around 30-36in diameter and i would be willing to pay $1500 Australian. The only major obstacle i can see would be the coil housing, it probably could be 3d printable unless there is some other option?
Don't be afraid to share your thoughts whether good or bad!!!

[eclipse]

The OO coils are commonly used in Bulgarian VLFs ("Grozdanka" and "Gadulka", and so on) which were very popular in the 90s. and still are by some older persons.
There are OO coil shells on ebay, you can get them cheap. Not sure if this will bring any improvement on the PI technology, I mean as far as I know the depth (and instability on the OO Vlfs is
high voltage TX and fine tuned resonance coil which causes instability with temperature shifts so nothing too much to do with the shape). Also huge drawback is the shape in my opinion. I had Nexus Coronado last year with 2x20 coil and ground coverage vs coil weight is probably the worst in the world, not to mention it was very unstable but that's another story.

[green]

G'day Coil Magicians, I have read that coplanar but specifically "OO" coils are pretty much the best coils to reduce noise and improve depth over highly mineralised grounds like we have here in Australia, I know the Nexus company makes these things but i am not sure if they are designed for IB or PI, and the price they are asking well, if i can't get any takers i will probably delve into this coil making business myself.
Now: if it's possible to work on PI, and specifically for SD 2200d, i would like someone to make me one of around 30-36in diameter and i would be willing to pay $1500 Australian. The only major obstacle i can see would be the coil housing, it probably could be 3d printable unless there is some other option?
Don't be afraid to share your thoughts whether good or bad!!!

Not sure what you mean by "OO". Including a picture of one of the coils I use for testing and the PI detector I'm playing with. I get better detection distance with it vs the mono coils I tried. Reduces ground signal and noise pickup vs a mono. Two 30in diameter coils side by side would make a very large coil.

[Qiaozhi]

Not sure what you mean by "OO".

Picture of an OO coil:

[green]

Picture of an OO coil:

Thanks, will that coil work with a PI?

[kt315]

Picture of an OO coil:

antenna

[waltr]

Thanks, will that coil work with a PI?

This OO looks like an Induction Balanced coil like a DD or Concentric of which do work with PI detectors. Big difference is Inductance of coils and NO resonant Caps. Then simply adjust over-lap to obtain a null during TX ON pulse.See my thread on the HH2 for some details on IB coil for PI.

[Carl-NC]

Thanks, will that coil work with a PI?

Yes, if the PI supports IB coils. The advantage of an OO coil is that it minimizes lift-off effect which is a problem mostly with VLF designs. It may show up in PI if you are trying to aggressively sample right up to the TX edge.

[green]

Does an OO have an advantage over a DD?

[Carl-NC]

Does an OO have an advantage over a DD?

Probably not. The sharp corners on a DD create small intense areas in the field that produce lift-off in a VLF as the coil is lowered to highly mineralized soil. The same thing happens with a PI but I doubt you would see it unless the sample delay is down to 1-2us. I could be wrong, I've never tested for this.

[Nova]

Thanks all for your replies, Carl says that it probably won't be any better than a DD, okay; can anyone tell me why 30in or bigger DD are not available to buy for pulse induction, is there a technical reason why they won't work?
I know of some Australian prospectors who tried many years ago to build a large DD at least 30in in diameter and was tried on a SD2000 that Bruce Candy had "low clocked" for them(what ever that means?) and from what i read about it, was not successful.
If it is possible to build a DD of at least 30in and have it working stable and at maximum depth over Australian mineralised ground on my machine(SD2200d) then my offer still stands, any takers?

[6666]

Have you tried giving Coiltec in Maryborough a call ?

And you could try and join up at http://australianelectronicgoldprospectingforum.com/ and ask your question there

[mschmahl]

Here https://www.nexusdetectors.com/after...archcoils.html you can order 30" concentric coils for the SD 2200d. There are some videos also.

[kt315]

here you can ask Eric directly. i read this "maximum depth over Australian mineralised ground" constantly but believe me now Eric
does all possible to do this work perfecto. https://www.geotech1.com/forums/show...Balance-Theory
read all 25 pages and you will in the matter too.

[dbanner]

Yes, an incredible 25 pages of ground balance theory.Superb thread.Your head will be spinning after first few pages.