Barracuda rev2

[Qiaozhi]

Does this apply to my board? I have the one before the geotech Rev2, mine is the Alex/ap rav2, Do I need to look into making the changes to the caps and un-connection to pin 2 ?

As Koala said, the original version has a number of issues. One of these is poor cancellation of EF.

It might explain it indeed, So what would you suggest? Should I contact Andy at sliverdog for suitable fix options ? or is there the link you sent me the bug fix?

The Build Document for the Geotech Baracuda Rev-A details all the changes made. You should also look at the two schematics to see the differences. You can modify the original board to include the updates, but you'll need to do a bit of cut-and-strap. However, I know it's possible, as that's how I initially tested the modifications. Or ... you could purchase one of the new boards.

[Tibuck19]

Thank you ill give that thread a read and try to figure it all out.

[Koala]

It might explain it indeed, So what would you suggest? Should I contact Andy at sliverdog for suitable fix options ? or is there the link you sent me the bug fix?

http://www.geotech1.com/forums/showthread.php?22964-Barracuda-Legend-Kit-Problems&p=215486#post215486

[Tibuck19]

It might explain it indeed, So what would you suggest? Should I contact Andy at sliverdog for suitable fix options ? or is there the link you sent me the bug fix?

[Koala]

Would explain the beep on swing. There was a bug on the original boards Earth Field. I have not upgraded mine yet.

[Tibuck19]

Does this apply to my board? I have the one before the geotech Rev2, mine is the Alex/ap rav2, Do I need to look into making the changes to the caps and un-connection to pin 2 ?

[Qiaozhi]

Good morning, Honestly, I didn't recall reading a build Document, I have read the barracuda would make a all round good coin MD which is also the reason I got a MMP also, I just wanted to gain more soldering experience and knowledge about DIY MD, before building the MMP, The Cuda will be the one, I plan to take in snow dumps to hunt for coins and lost items for the fun of it, the cities round here use calcium and salt for ice, which is why I though pi would shine. and as for the what's and why's of the coil size, it is basically due to the maximum print volume of my 3d printer which I used to print, a pre coil winding jig that get mounted on my lathe, then gets inserted the 3d printed coil housing. I am just about finish the cad drawing to a 296mm X 198mm rectangular shape coil jig and housing, it will give more linear length (coil size), which might help for depth, but being strait lines with soften corners, I have no clue how the EF will form and hold. BTW thank you for your help, the magnet over the coil, was something great to learn, till now I have not read about any where .

The Build Document is here -> http://www.geotech1.com/forums/showt...roject-Details

[Tibuck19]

Good morning, Honestly, I didn't recall reading a build Document, I have read the barracuda would make a all round good coin MD which is also the reason I got a MMP also, I just wanted to gain more soldering experience and knowledge about DIY MD, before building the MMP, The Cuda will be the one, I plan to take in snow dumps to hunt for coins and lost items for the fun of it, the cities round here use calcium and salt for ice, which is why I though pi would shine. and as for the what's and why's of the coil size, it is basically due to the maximum print volume of my 3d printer which I used to print, a pre coil winding jig that get mounted on my lathe, then gets inserted the 3d printed coil housing. I am just about finish the cad drawing to a 296mm X 198mm rectangular shape coil jig and housing, it will give more linear length (coil size), which might help for depth, but being strait lines with soften corners, I have no clue how the EF will form and hold. BTW thank you for your help, the magnet over the coil, was something great to learn, till now I have not read about any where .

[Qiaozhi]

That is basically what I would need it for or I would of bought one years ago lol, I'll hunt around see what I could find, In mean while, waving the magnet over the coil and adjusting the trimpots I was about to get it not to beep while swing , but I lost a lot of depth, So I re-winded another coil of 372 uH repeated the pleasant magnet waving dance, and For most American and Canadian coins I can clearly detect at 7 1/2 inch for all and if I push the threshold I can get an extra inch but with some beeping on back swing, a small bit of gold is 5" ish a ring comes in about the same as coins. I am wondering if it would be worth making a 400uH plus coil ? But honestly, what are normal depth for a 6X10 coil with the Cuda board ?

As mentioned in the Build Document, the Baracuda is a little bit defective in the sampling department, in so much as the main and EF pulse widths do not track each other very well. This is due to the simplistic circuitry used to generate the pulse widths and delays. It is quite possible that, due to component tolerances, your particular build is not cancelling the EF effectively when pushed to the limit. Trying different coils will not help.

The depths you're achieving for the 6" x 10" coil seem about right.

If you're trying to detect small gold, then the Minipulse Plus is a much better design for that purpose. The Baracuda is intended for finding coins at the beach.

[Tibuck19]

That is basically what I would need it for or I would of bought one years ago lol, I'll hunt around see what I could find, In mean while, waving the magnet over the coil and adjusting the trimpots I was about to get it not to beep while swing , but I lost a lot of depth, So I re-winded another coil of 372 uH repeated the pleasant magnet waving dance, and For most American and Canadian coins I can clearly detect at 7 1/2 inch for all and if I push the threshold I can get an extra inch but with some beeping on back swing, a small bit of gold is 5" ish a ring comes in about the same as coins. I am wondering if it would be worth making a 400uH plus coil ? But honestly, what are normal depth for a 6X10 coil with the Cuda board ?

[Qiaozhi]

would something like this do ? Goldstar Oscilloscope OS-7040A 40MHZ its cheap ish around a 100$ before bargaining hahahaha

I used to have a 20MHz version of this scope. It's quite old, but will be good for working on metal detectors.

The EF pulse is located at U4 pin12, and the main pulse is at U4 pin 10. There is no adjustment for either the main or EF sample pulse widths. These are fixed by the component values. The delay pot adjusts the delay between TX-off and the main sample. It also affects the EF pulse delay.

[Tibuck19]

would something like this do ? Goldstar Oscilloscope OS-7040A 40MHZ its cheap ish around a 100$ before bargaining hahahaha

[Tibuck19]

crap lol I was afraid you would say that! I don't have a scope, But seeing how I still have the Surf pi to tune and have the MMP kit still waiting to be populated I might look in to buying a used one. but for knowledge sake, EF Pulse ? that is my delay pot, correct? and which pin should I be using the Scope on ?

[Qiaozhi]

Good morning, Yes it beeps , not the same as a coin it has a weaker double beep, Maybe it the wire to the unit ? this is the cable I used http://www.cercocable.com/products/d...ew.php?p=19170

If it beeps with the magnet, then the Earth Field is not being eliminated properly. Using a scope, check that the EF pulse is located at the correct time, and has the same width as the main sample pulse.

[Tibuck19]

Good morning, Yes it beeps , not the same as a coin it has a weaker double beep, Maybe it the wire to the unit ? this is the cable I used http://www.cercocable.com/products/d...ew.php?p=19170