Barracuda rev2

[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 ?

[Tibuck19]

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

[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]

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]

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]

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]

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]

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 ?

[Koala]

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

[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]

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/showt...486#post215486

[Tibuck19]

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

[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]

I am undecided at this point what I ll do with it , I e mail Andy, seeing how he is my vender, buying a new kit is out of the question seeing how I already bought one and in my option someone somewhere probably knew there was a problem when I purchased the kit, But the facts are either I keep a few spare 7660 encase I burn another one, and except the fact I can only detect in the 6- to 8 inch max search depths and still have a ground balanced detector, and leave well enough alone, Or attempt the mod to bring this board back to do what it was intended too, but i'm far from being an expert at electronics, Depending on what Andy has to say, and if you can insure me that a Noob like myself, could under take the mods, I might try it knowing I could have a good MD or a dead one loll. I seen in the photos there is a second Pot to the cuda mod, What is that and would it be worth adding ? And Thank you very very much for all your help an, pointing me in the right direction my issues, Being new to all of this and doubting how I made my coils, thinking the detect was working right not understanding what I was doing wrong. Lucky I still have the Surf pi to mess around with and the Mini pulse plus could be my saving grace here.

[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 ?

I am undecided at this point what I ll do with it , I e mail Andy, seeing how he is my vender, buying a new kit is out of the question seeing how I already bought one and in my option someone somewhere probably knew there was a problem when I purchased the kit, But the facts are either I keep a few spare 7660 encase I burn another one, and except the fact I can only detect in the 6- to 8 inch max search depths and still have a ground balanced detector, and leave well enough alone, Or attempt the mod to bring this board back to do what it was intended too, but i'm far from being an expert at electronics, Depending on what Andy has to say, and if you can insure me that a Noob like myself, could under take the mods, I might try it knowing I could have a good MD or a dead one loll. I seen in the photos there is a second Pot to the cuda mod, What is that and would it be worth adding ? And Thank you very very much for all your help an, pointing me in the right direction my issues, Being new to all of this and doubting how I made my coils, thinking the detect was working right not understanding what I was doing wrong. Lucky I still have the Surf pi to mess around with and the Mini pulse plus could be my saving grace here.

I cannot really advise you as to whether you should do the mods or not. If you brick the unit, then you'll blame me.
It depends on how confident you are with electronics.

You must have bought the original Baracuda PCB quite some time ago, as Andy doesn't supply those any more since the Geotech Baracuda REV-A was released. It's been know for many months that Baracuda builders have experienced problems, but it was always assumed that it was inexperience on their part. While assisting one particular member online, I eventually requested that he send me the board for investigation. That was when I managed to isolate all the design errors, and created a special Geotech version in order to distance it from the previous problems. It was also renamed as REV-A, since there are several alternative numbered versions around, all of which are defective. It is not known whether the original Anchor Electronics' units had the same issues, or whether these were introduced during the back-engineering effort. The previous PCB was designed by Alexmex, but he simply used the back-engineered schematic. Several people have had their finger in the pie, so who knows the answer. Andy only supplies what is requested, so the blame doesn't lie there.

The bottom line is that you either bite the bullet and do the mods [very carefully], or buy the latest REV-A PCB. It's only £7.00.

Your decision ...