Remaining issues

[rickb]

From the pdf.

The intention here was to keep the design as close to the original as possible, but to remove the existing design flaws without making major changes. As a consequence, there are still a few fundamental issues that could benefit from a redesign, but that is beyond the scope of this exercise.

Can you at least note what these remaining fundamental issues are?

Rick

[Qiaozhi]

Can you at least note what these remaining fundamental issues are?

Rick

The other issues are eluded to within the Build Document, but essentially they are related to the 40106 IC.

The main and Earth field pulse widths are not well matched, so EFE is compromised. Due to component tolerances, the amount of this discrepancy varies between different builds. Also, below about 20us delay, the sample pulse width becomes increasingly smaller (as does the Earth field pulse), but the amount they both decrease is not identical. These are problems that could be resolved by using monostables (in a similar manner to both MiniPulse Plus and Hammerhead) but I didn't want to go down that route, since it would fundamentally change the simplicity of the Baracuda design. So, although these changes would improve the overall operation, it could no longer correctly be called a Baracuda. As I said earlier ... it is what it is.

There are several PI designs available on Geotech, and they all have their strengths and weaknesses. One of the Baracuda's strengths is its simplicity, but it was let down by unreliability due to some poor design. All tests with the Geotech Baracuda REV-A show that unreliability and component failure are now a thing of the past, so you can go ahead in confidence that this detector does actually work. The addition of a Build Document (in the same manner as the MPP) should also help to eliminate some of the more common errors that constructors had with this design. The important thing is to build the design step-by-step, and test each stage as you go. Then you'll have a fighting chance of ending up with a working detector.

Just in case you're wondering why this is Revision A, and not (say) Revision D, is to prevent any confusion between other versions floating around on the internet. Hence why this variant has been renamed to Geotech Baracuda, to distinguish it from other (often unfinished) versions by other people.

[rickb]

So the bottom line is, do the upgrade if you have one, but pick a different PI if starting from scratch.

Rick

[Qiaozhi]

So the bottom line is, do the upgrade if you have one, but pick a different PI if starting from scratch.

Rick

It depends on what you want to use the detector for. If you're looking for a simple PI design to use on the beach, and to search for coins, then the Baracuda is more than adequate. Alternatively, you could build a Surf-PI that does the same job. However, the Surf-PI doesn't have an associated Build Document, and (although it is also a simple design) many electronically-challenged members have had problems. So in that case, the Baracuda would make a good first project.

[ripsdevala]

Hi Qiaozi,
Thanks for the latest official baracuda, but i cant find the layout, pcb to print or lay file, i like to test it.

Rips

[Qiaozhi]

Hi Qiaozi,
Thanks for the latest official baracuda, but i cant find the layout, pcb to print or lay file, i like to test it.

Rips

Like the MiniPulse Plus, the PCB layout files have not been posted, but I will post the Gerber files later.
The PCB database is from Easy-PC, so this would not be useful for most members anyway. Also, the layout is double-sided with plated-through holes, and a ground plane on the bottom layer. This would be an extremely difficult PCB to make yourself at home using nasty chemicals.
Silverdog provides a valuable service to the Geotech community, and I would urge you to purchase a PCB from there.

By the way, I do not receive even one penny for my efforts on this project from any source, and it is provided free-of-charge for your enjoyment.

[Qiaozhi]

Gerber files have been added -> Geotech Baracuda - REV-A - Project Details

[Teleno]

George, which software are you using to draw the schematics? Would you mind posting the .sch file so people can to edit some mods without having to redraw the whole thing?

[ripsdevala]

Thanks alot Q, let me try with my manual working pcb. I try many times to buy from silverdog from the first time i join here, but I never got an answer, so the only option I have is make it from the scrap.

[Qiaozhi]

George, which software are you using to draw the schematics? Would you mind posting the .sch file so people can to edit some mods without having to redraw the whole thing?

The software is Easy-PC. You might be able to edit the schematic by downloading a demo version.

[Teleno]

The software is Easy-PC. You might be able to edit the schematic by downloading a demo version.

Thanka! It would be nice to have the .sch of the MPP rev-D , as that's the one I have built and am playing with.

[Qiaozhi]

It's off-topic for this thread, but here it is:

[bernte_one]

can´t say enough thanks to you george

btw i should tell you some greetings from christian (Detektorforum.de) he told me that you meet each other some years ago

[nickel_n]

What are the PCB dimensions of the new Geotech Bara?
I would like to know if it will fit in a 90mm storm water PVC pipe enclosure.
Thank you

[silverdog]

What are the PCB dimensions of the new Geotech Bara?
I would like to know if it will fit in a 90mm storm water PVC pipe enclosure.
Thank you

Same as the old one 95 x 65mm