Simple Russian PI detector Pirat

[6666]

I had good results with Russian pirate some two years ago. My coil was 15cm diameter, 24 turns,0.4mm. I was getting 5 inches in wet sand on most coins. Very stable. Damping resister I used was 220 ohms. I used tl072 op amp. Maybe good for making pinpointer?

dbanner, would you please post the schematic that you used here, thanks.

[dbanner]

I had good results with Russian pirate some two years ago. My coil was 15cm diameter, 24 turns,0.4mm. I was getting 5 inches in wet sand on most coins. Very stable. Damping resister I used was 220 ohms. I used tl072 op amp. Maybe good for making pinpointer?

[BKY1337]

Yes, ok.

[homefire]

Way back when I showed the Signal Train. Fet to Audio. Even stated the Audio was generated by the FET switching. Remember that bit ?

[BKY1337]

The battery is not the problem. It doesnt work with 12V too. And nobody said that i need a oscillating signal through the op amp to the speaker.
I think try and error is a good way to learn the basics.

I also said that i hooked up the battery wrong and this was the problem.

Thanks for your help anyways!

[homefire]

Yes. My bet is the rest of the circuit was lucky to see a few Volts to work with. If he measures the +/- while operating it will show the truth.

[kt315]

there is not common understanding of electronics basics. people learn it on a way... by hands, not head...
why? i do not know. there is even not a current the issue, Homefire... there is still inside resistance
of the PP3... and it is huge...

[homefire]

LOL You Using the PP3 or 9v battery block was your issues from the start. They can only produce like 135ma or so and when running the FET is all but a Direct Short.

[BKY1337]

Not both, only one. I meant that both layouts are ok.
I need to wait for my K157ud2.

[6666]

BKY1337, I am glad you found the short under the Op Amp, and both are now working.

[BKY1337]

I meant that i have a 200Hz input and a 200Hz output. At the LM358.
The Unit is working now , i had a bridge which shortened the circuit under the Operational Amplifier.
I used the last schematics with pictures here in the Thread. They are both working, but i shot my K157ud2 at the other one and i need to wait for a new one.

I saw that the version with TL082/TL072/LM358 has not so much depht.

My version with the russian K157ud2 was stronger and also louder and more stable too.

I used regular 9V batteries first, then i used a transformator 12V.

I had 15cm with a 1 Euro coin with the 15cm coil , but my coil is not perfect , too less windings just 12 windings 15cm diameter.
The K157ud2 was better , or was it just because the sound was louder, i dont know.

[6666]

BKY1337, what does this statement mean ? " I can follow the oscillating signal til the speakers, through the op amps."

And would you mind telling me exactly which schematic you are useing ?

Also what type of battery are you useing ? are you useing a small 9volt battery ? if you are then you are asking a lot from it
also is it a carbon zinc or alkaline battery ?

6666

[BKY1337]

Its not much at the other side, i think i can do it one side and connect the other pins at the other side with wire.
But i think i will try the Pickini first.

[homefire]

Surt Long is two sided. I have nothing that only shows traks

[BKY1337]

Coil works now. But still no sound. I can follow the oscillating signal til the speakers, through the op amps.
I couldnt do this with my other version. There was nothing oscillating at 200Hz. Its still too less voltage at the speakers only about 50mV.

Also the input wasnt oscillating at the op amp. I wanna bring the two PCBs to work.

I want to etch my own pcb. Is the surf pi double sided? How long is the longboard?
My copper clad boards are only 160mm long.