Simplest PI detector possible?

[Hammerhead]

If you want to build the Russian Pirat then use the Layout with the K157UD2, it works better.
25cm for a 1 Euro coin. If you want more then build the surf pi or maybe the barracuda.

There are also Kits at ebay for the Pirat Pi with K157ud2.

https://youtu.be/Daa7hiI_Svc

[6666]

https://youtu.be/Daa7hiI_Svc

hammerhead your project works very well, which schematic did you build from ? thanks

[Hammerhead]

hammerhead your project works very well, which schematic did you build from ? thanks

Thank you 6666
That's all you need[ATTACH]42500[/ATTACH]

[6666]

Thank you hammerhead for posting the information.

[Tim]

Yes the K157 is by far the best version. I have previously designed (but not built) this DD version in Express PCB. I built it for mono with TL082 but was not very good. Perhaps it would be better with LM358, but I suspect re-designing this DD to accept K157 would be a better option. Just putting it out there in case someone's interested.
There may not be any advantage, but nothing ventured, nothing gained.

[6666]

Thanks Tim, is there an actual schematic ?

[Tim]

Thanks Tim, is there an actual schematic ?

Yeah mate. I put it up there. I think that's the one I made the Express from, anyway the only DD schem I have.
Cheers.

[6666]

my mistake yes its there must of had the mouse placed wrong, cheers

[pigeon]

hi dear all friend

what is the equivalent of k157

thank you veru much

[kt315]

K157UD2 is obsolete. so old that your grandfather did know it be a youngster as modern.
LM301 2pcs in one case.

[pigeon]

K157UD2 is obsolete. so old that your grandfather did know it be a youngster as modern.
LM301 2pcs in one case.

ok thqnk you

[Eddy71]

In my "PI-tone" I tried to use TL072 instead of K157UD2, it works quite well.


http://www.mastervintik.ru/prostoj-i...iskatel-pirat/

as on this page

[BKY1337]

Im my opinion it's not worth to build the Pirat Pi with LM358 or TL082/072/062. I had only 20cm depht at a coin and only a weak tone.

The K157ud2 gives a strong signal and a better depht. You can buy it at ebay. Maybe not in the US. But from Europe.

I have heard that some guy used an other substitute for the LM358 i guess it was some LF... OpAmp. He said that he got better resulsts with it.

[Tim]

Thanks Eddy. Yes agree with BKY, but should check values of TL072 schem compared to K157 for changes.

[Eddy71]

Im my opinion it's not worth to build the Pirat Pi with LM358 or TL082/072/062.

I checked in the scheme TL062,072, 082, LM358.

LM358 and TL062 worked really badly.

But TL072 and TL082 worked very well.

The resistor parallel to the search coil had to be selected to suppress the parasitic oscillations.