BARACUDA-Legend-1

[Qiaozhi]

OK, now I am confused.... I thought the Barracuda does have some discrimination abilities related to the audio tone ?

Dave Frank

Only conductivity discrimination is available in the Barracuda, by adjusting the main sample pulse delay. This enables targets with low conductivity, such as small sized targets (gold nuggets, thin jewellery, small nails, etc.) to be rejected. In essence, any target in which the eddy currents die away before sampling takes place. Unfortunately, ferrous targets (except very small items) are still detected, as eddy currents in these items will continue to circulate for much longer. PIs are very sensitive to iron, which is why you don't see anyone at a metal detecting rally using one. The Barracuda is really designed for beach use, as it has the ability to ignore wet sand. This is for the same reason I mentioned above - the eddy currents in the wet sand die away after only a few micro-seconds.

[bernte_one]

modified to be very cheap and and easy to rebuild

hello new coil fits good to stem
works great very lightweight

[gcause]

That looks awesome bernte_one!!!

Better than a bought one

Where did you get the fittings to allow it to be telescopic?

Could you please describe the parts you used for the upper and lower shafts and the handle.

[gcause]

Barracuda not working

Hi All,

Just got my kits from Silverdog.

I cant get the Barracuda to work.

Have talked to Mr 6666 on another forum and he suggested setting voltage on Pin6 of U2 back to zero volts using a multimeter and have done this.

Have checked the 2222 chip is in the correct way it is a tin pot and the tag is facing E as per the silkscreen layout.


I thought it might have been my test coil but I have since wound a 200mm 28 turns of .5mm enamel wire to give a 452uH coil and it still doesnt work.


Can anyone spot anything obvious from the pictures?

Here is the kit that came:



Here it is all laid out:



Here it is all together:



Here is the bottom view:




Had to put a big heatsink on the main transistor as it was getting very hot:



Here is my test rig. The jiffy box has a power regulator circuit in it and I am using an old 12v rechargable drill battery and regulating it back to 9v.



I have checked the voltage and I am getting a constant 9v from the power supply.

Any help would be greatly appreciated.

[ApBerg]

Hello gcause,

The power the board take's must be +/- 75mA-100mA if higher there is a error.
The power transistor must not get hot..., check all parts close to the 40106 if they are o.k. in value , also check the solderpads if no solder-bridge's are made. Can you make some sharper photo's ? Now not much is to check, the photo's are to blur.
Are those 2 diode's that protect the NE5534 in the right place ? can not see clear..
Best regards and succes

Ap

[dfbowers]

Hi All,

Just got my kits from Silverdog.

I cant get the Barracuda to work.

Have talked to Mr 6666 on another forum and he suggested setting voltage on Pin6 of U2 back to zero volts using a multimeter and have done this.

Have checked the 2222 chip is in the correct way it is a tin pot and the tag is facing E as per the silkscreen layout.


I thought it might have been my test coil but I have since wound a 200mm 28 turns of .5mm enamel wire to give a 452uH coil and it still doesnt work.


Can anyone spot anything obvious from the pictures?

Here is the kit that came:



Here it is all laid out:



Here it is all together:



Here is the bottom view:




Had to put a big heatsink on the main transistor as it was getting very hot:



Here is my test rig. The jiffy box has a power regulator circuit in it and I am using an old 12v rechargable drill battery and regulating it back to 9v.



I have checked the voltage and I am getting a constant 9v from the power supply.

Any help would be greatly appreciated.

To start with, do not install Q5. Other than that, the kit should work just fine unless you installed something backwards

[TH Jim]

Hi folks,

I've finally finished my Barracuda - at last!

Took her for a little test at the beach a couple of days ago and had the best of luck (seriously jammy some might say!). Switched her on and within one or two sweeps I got a nice loud clear signal, dug it up and it turned out to be a lovely old rose gold ring weighing 6 gramms. It has a date letter 'g' which indicates it was made in 1906. After walking back up the beach to show my mate the ring I went back to the same spot and the same thing happend again - two or three sweeps and out pops another gold ring! The second was smaller though and is not marked. Carried on detecting for about another hour and also bagged a 1943 sixpence, a badge and some ammo. All of which can be seen in the photo below.

The Barracuda is a sweet little machine, I really like it, but the 2 gold rings coming out immediately was obviously a fluke. I was just lucky to hit the part of the beach that had been eroded.

Regards, Jim.

[TH Jim]

Barracuda disassemble for transport.

[TH Jim]

Put together.

[TH Jim]

Lengthwise.

[TH Jim]

Finds.

[TH Jim]

Some more info on my Barracuda Here:

http://www.geotech1.com/forums/showt...148#post140148

[bernte_one]

That looks awesome bernte_one!!!

Better than a bought one

Where did you get the fittings to allow it to be telescopic?

Could you please describe the parts you used for the upper and lower shafts and the handle.

hello gcause
thanks

all is made from high pressure water pipe(16bar) from hardware store
these connectors are made for them t-connector is 20/20/20mm
the other connector is for 20 to 25mm (lower shaft to upper)
bending the tubes is made with a spring in the pipe then heaten up and bended around a thick metal pipe or anything other round form
if you have no spring you could use ordinary sand ore birds sand from petstore
armrest is made also from bigger waste water pipe with soft rubber
grip for hand is from bicycle (use some lubricant like aquaglide to fit it on)
regards

[didier]

Baracuda adjustment

Hello, I ordered a board (not the kit) from Silverdog for my Baracuda project and mounted all components . It is my first detektor I build up and therefore I do not have any experience. I made a preliminary coil with 26 turns of 0.5 mm copper wire and about 22 cm in diameter. The baracuda works.
But now it is very unclear for me how to proceed. I could not find a instruction how to adjust step by step the trimmers in this thread. How to begin ?

There is a trimmer for the balance, what is the criteria for this one ?

There is a delay trimmer, on the schematic there is a trimmer on the board (25K) and a external one 10K) but on the siverdog board I see only the 25 K trimmer. Is there a need to connect a external trimmer with 50k for the delay ? I could not see how to connect this on the board. What is the criteria for the delay ?

What works fine is the 50 K poti for the treshold.

The baracuda is sensitive for moved objects, means when I move a metal next to the coil it makes a sound. The Fet Q5 has no function. When I remove it I have the same performance. When I connect the gate of the fet to ground, the baracude does not work any longer even when I tune the treshold.

I would be very happy if anyone could help me to proceed.

Didier

[dfbowers]

Hello, I ordered a board (not the kit) from Silverdog for my Baracuda project and mounted all components . It is my first detektor I build up and therefore I do not have any experience. I made a preliminary coil with 26 turns of 0.5 mm copper wire and about 22 cm in diameter. The baracuda works.
But now it is very unclear for me how to proceed. I could not find a instruction how to adjust step by step the trimmers in this thread. How to begin ?

There is a trimmer for the balance, what is the criteria for this one ?

There is a delay trimmer, on the schematic there is a trimmer on the board (25K) and a external one 10K) but on the siverdog board I see only the 25 K trimmer. Is there a need to connect a external trimmer with 50k for the delay ? I could not see how to connect this on the board. What is the criteria for the delay ?

What works fine is the 50 K poti for the treshold.

The baracuda is sensitive for moved objects, means when I move a metal next to the coil it makes a sound. The Fet Q5 has no function. When I remove it I have the same performance. When I connect the gate of the fet to ground, the baracude does not work any longer even when I tune the treshold.

I would be very happy if anyone could help me to proceed.

Didier

You can adjust the d.c. offset pot for 0v on pin 6 on the ne5534. Other than that, you can set the delay as low as possible for best performance. I generally set mine at 25uS.