BARACUDA-Legend-1

[TH Jim]

A few of us have finished the Barracuda and some have reported excellent results. I am still trying to get mine tuned up, it doesn't yet match the performance of my SurfPI, but i expect it will eventually.

These are Pulse Induction machines and as such have no discrimination, if used in a forrest you will be digging up a lot of small pieces of iron, you might be better off with a VLF.

[Janou]

Hi! 6666
I have built 3 surfmaster and the long PCB designed by ApBerg is certainly better.
Dirceu

Hi,

Any opinion about performance/datas between Surfmaster and Baracuda ?
Schematics are pretty similar, so normaly it must be similar performance.

Somebody already finish Baracuda and have more pictures about the project finish ?
Another query, do you think it's a good detector for "standard" use in forest for exemple ?

[DIRCEU]

Hi Dirceu
thanks for info on the coil, great that it works so well for you
would you mind explaining a bit more about what

"coal from exhausted batteries" means thanks

I have some elmers glue

HI! 6666

Well! Here in Brazil there is no sprays for shielding, so I was forced to be manufactured from depleted batteries common type C (medium size). I open the battery and remove the black substance and mix it with white glue for paper until a consistent mass and then applied with a brush ... only this.

Make a test on a sheet of paper and let dry after 4 hours measure the resistance


Best Regards
Dirceu

[TH Jim]

Hi Alexis

Thanks very much for supplying the scope pics of the original Barracuda waveforms - very helpful, thank you.

ApBerg, thank you for all your advice and helpfull suggestions, I have seen now that if the offset is set to high then this is what corrupts the pulse on pin 2, when the offset is lower there is a cleaner shape to the pulse.

I have not had time to do much work on the Barracuda at the moment as the tides have been long and so I am busy out on the sands with the SurfPI, but will have another try at tuning it up in a few days time.

Regards to all, Jim.

[plumabob]

OK my testing is completed. I have found that different spec coils need to be adjusted individually at the 25K pot on the board. I replaced mine with a single turn rather then the supplied multi turn pot. Just works a lot easier for me. My coil is as stated a factory spec 11 inch. Nickels come it strong at 12 inches but can still be heard faintly at 15+. Some of my larger gold rings are seen even further away. Soda can at an easy 30 inches. Sensitivity to small gold jewelry is pretty good but could be better. Coil size probably has something to do with that I'm certain. All other board components are what was supplied by Silverdog.

Question..... I did not have to add a damping reisitor at all. Is that the purpose for the 25K pot on the board to tune in different coils. I tried a 2k pot across the coil leads to find the correct damping resistor but my scope pic never changed no matter what setting. Is it possible it is not needed?

Also has anyone found a way to drop the delay settings lower instead of the minimun 22us?

Bob

[6666]

Hi Dirceu
thanks for info on the coil, great that it works so well for you
would you mind explaining a bit more about what

"coal from exhausted batteries" means thanks

I have some elmers glue

[DIRCEU]

Dirceu

what coil did you use on your surfmaster ?
thanks

Hi! 6666


I'm currently using an oval shaped coil of 26cm/15cm. The wire has Teflon insulation. The shield was made with coal from exhausted batteries and Elmer's glue. The inductance is 145uH and 0.9 ohms of resistance. I mainly use this coil on the beach in the sand as far into the water.

I have built 3 surfmaster and the long PCB designed by ApBerg is certainly better.


Best regards
Dirceu

[plumabob]

Got my cuda working. Went with a close to factory spec coil .452uH, 1.31R. So far very pleased with the performance. I will post some results as soon as my testing is completed.


Nice project Silverdog!!!


Bob

[6666]

Dirceu

what coil did you use on your surfmaster ?
thanks

[Alexismex]

You can see the adjustment of the first window with Delay in position Zero and second window

[Alexismex]

More Photos from baracuda original ....see the noise in the last

[Alexismex]

Some photos make in the original Baracuda
Pin2 Q3...First window(2V/20uS)
U2 pin 6 (2V/20uS)
output of 5534 (2V/20uS)
Window 1 DELAY position Zero
Pin 4 Q4 (2V/ 50uS)
U2 pin 6 (200mV/10uS)

[DIRCEU]

To 6666

Many thanks for the link.

Regards
Dirceu

[DIRCEU]

Hi! ApBerg.


My surfmaster can detect a gold ring at a distance of 27cm.
I'm trying to detect a broken gold ring with various types of coils but without success.
Today I will start building the Barracuda. I use the LM 358 because I'm not finding the LF 412.
Anyway thank you for answer my question

Best regards
Dirceu

[6666]

When building the bara
make sure you get the 2222a in the right way