BARACUDA-Legend-1

[wizz737]

Hi folks, Has anyone had success making a DD coil for the bara, I've read it's been done to the surf pi and work good. In this arrangement Would the inductance of each coil be same as a mono coil? example 450uf each coil or does the inductance of both coils equal a single mono coil inductance? Would the coils be wired in series? You're thoughts would be much appreciated.

Best Regards,

[wallker]

Finished my double layer planar coil (blue one in the middle).
Results are good with very light threshold i got 2€ coin 30cm+.
Coil has 380mH and 2R8.
All what i need simple and small. Perfect for the playing yards in my neighborhood.
(I know i need a new frontplate after my external pots modded)


thanks to all for advice

good sleeping

Hi bernd,
could you post some more information about your coil(wire thicknes,number of turns,in diameter and od diameter).
Regards.

[Rumcajs]

Dear Nikolaj,

where are your damping resistor from your photo?
a) Please never testing your circuit without damping resistor (220-390R min.1W!).
b) We strongly recommended mounting the steel cooler plate in the TIP127(why use TIP127?)
From this position better an FET (for example IRF9640 & Co.)
These a) and b) parts are heats (approx 60 Celsius is normal , i think.)

My suggestions:
1) 555 Oscillator working? Not halted?

2) If working, please check the oscillator time period. if the period is very short (higher freq.)
it is quickly opening the power transistor, and battery current is higher
(The normal PI-s are uses approx 100-225Hz, sorry im dont remember the Barracuda freq. The battery power is concerning with freq. and tank capacitor, but approx 100mA is very good for metal detecting.).

3) Oscillator capacitor is good value? For example: in the drawing write is 47 nF, and you use 4,7 nF (check for your drawing for the correct values -- im dont remember.)

4) About oscillator part not an short circuit? For example: potentiometer connections, panel, etc.

Brg

Rumcajs

[wallker]

I was busy couple of days,but sunday is a day for barakuda
I will make a few turns for some coils,but after replacing TIP 127 (which is burned up when i was looking damping resistor value...) with some substitute...
What would you recomended for substitute ?
Best regards.

[maikl]

Q2 is MPS 2222A=PN 2222A and must be positioned this way(PCB is designed for metal case transistor)...it work's very fine without removing Q5 check out pins:

You're right wallker. How does the new coil?

[silverdog]

Baracuda Special Price

Just put these on special price for a while

[wizz737]

Hello Detecto, You will not be disappointed building the Baracuda. Excellent results can be obtained and easy project to build. I was very surprised at how well the bara preformed, with a good coil design it's amazing the depth of detection.

all the best

wizz737

[detecto]

Baracuda

these days reeding all your posts abouth baracuda i concluded that baracuda is very good pi detector so i start building this tiny buth very good detector, i hope i will be satisfied.
Regards
Detecto

[wallker]

MPS 2222A

Q2 is MPS 2222A=PN 2222A and must be positioned this way(PCB is designed for metal case transistor)...it work's very fine without removing Q5 check out pins:

[maikl]

Hi wallker. If you already have the wire you try and let us know the results... do not be afraid you will not spoil anything... but I wonder that your Barracuda works with such position Q2=PN2222 ???

[wallker]

Hi,
I just finished my baracuda and is working with quick done search coil from 0.5 mm stranded pvc insulated wire on 200mm diameter with 29 turns.
Now i want to make a coil(with your's help) for small nudgets of gold ie. 3-4 gr.
I have some enamel copper wire 0.25mm and i wonder how would work if i do double winding with this wire on 200 mm diameter with 28 turns?
Sorry for my English.
Here some pictures:

[maikl]

hello

i search for measure points to tune my baracuda with oszi
so please if somebody could tell me the best points

for example
coil damping value (for the case a potentiometer is inserted instead of resistor)
delay
offset
fine tune settings

regards and good night

A good example is Qiaozhi post #6 http://www.geotech1.com/forums/showthread.php?t=18807

[6666]

Nickolaj


What Ap said, the ne5534 appears to be reversed the dot should be near the pot

[bernte_one]

hello

i search for measure points to tune my baracuda with oszi
so please if somebody could tell me the best points

for example
coil damping value (for the case a potentiometer is inserted instead of resistor)
delay
offset
fine tune settings

regards and good night

[Vermeer111]

Very good find Bernte on cheaper as my find, have you try it with a tl072 ? this is, in the moment, my configuration.Very good, very stable and good sensivity.greetings from the harz montains.