Polish Pi

[dbanner]

I do not know where the wrong This is another version Please help
https://youtu.be/8oYblCz8Yhk

Ha! looks like the problem might be the way the preamp chip is coupled to the circuit. What chip are you using, LF357 or TL081 or UA709 ????

Post the layout and schematic of the pcb for the one that is shown in the youtube video. It seems that it is working but for some small problem in the pre-amp section, it is not detecting.

[Vadim18]

I do not know where the wrong This is another version Please help
https://youtu.be/8oYblCz8Yhk

Hi Hammerhead!
I'll try to help.
1. Check if transmitter is worked or not, put some small can (soda or coffe can) close to coil - you must hear sound.
2. Tune power of your transmitter (PR2 100K - NE555 potentiometer), R8 and R9 resistor should be a little warm, but not cold.

If TX is worked but detector don't - check zener diode zn 3.3V first, cheap electronic parts in this place of circuit are often "not survive".

You can made simple update for this unit:


Good luck

[MartyJ1963]

@DB,,,,I added all the components that were missing from the polones layout you posted,,,The '100uf' Capacitor in the top left corner of the pcb (C23) is in the parts list but I can't find it anywhere on the schematic. Also, if this was the pcb you made, could you post a pic of your board for me because I can't tell the correct orientation of the 2 x 47uf Capacitors in the top left above the 4001's, the picture in the document/build file you posted doesn't show which terminal is plus or minus. If this is the working pcb you made I may redraw it smallerbecause theres a lot of empty space and it's quite a large board,,,Regards, Marty

[MartyJ1963]

@Vadim18,,,,,Do you have a working pcb layout that you wouldn't mind sharing please? Thanks, Marty

[Hammerhead]

Hi Hammerhead!
I'll try to help.
1. Check if transmitter is worked or not, put some small can (soda or coffe can) close to coil - you must hear sound.
2. Tune power of your transmitter (PR2 100K - NE555 potentiometer), R8 and R9 resistor should be a little warm, but not cold.

If TX is worked but detector don't - check zener diode zn 3.3V first, cheap electronic parts in this place of circuit are often "not survive".

You can made simple update for this unit:
[ATTACH]49803[/ATTACH]thank you my friend Make adjustments
And tell you the result
Good luck

Thank you and stay safe

[Hammerhead]

Ha! looks like the problem might be the way the preamp chip is coupled to the circuit. What chip are you using, LF357 or TL081 or UA709 ????

Post the layout and schematic of the pcb for the one that is shown in the youtube video. It seems that it is working but for some small problem in the pre-amp section, it is not detecting.

banner Hello This is the layout And some pictures sent by a friend from Greece
Thank you and stay safe

[dbanner]

@DB,,,,I added all the components that were missing from the polones layout you posted,,,The '100uf' Capacitor in the top left corner of the pcb (C23) is in the parts list but I can't find it anywhere on the schematic. Also, if this was the pcb you made, could you post a pic of your board for me because I can't tell the correct orientation of the 2 x 47uf Capacitors in the top left above the 4001's, the picture in the document/build file you posted doesn't show which terminal is plus or minus. If this is the working pcb you made I may redraw it smallerbecause theres a lot of empty space and it's quite a large board,,,Regards, Marty

Yes, I made this layout. It seems I left out the 100uF capacitor on my build. This was a long time ago, so can't remember all the details of who, what, when, and why.

[MartyJ1963]

@DB,,,,Thanks for the Pic you posted, I've re-oriented those 2 Capacitors now, Regards, Marty.

[Hammerhead]

Ha! looks like the problem might be the way the preamp chip is coupled to the circuit. What chip are you using, LF357 or TL081 or UA709 ????

Post the layout and schematic of the pcb for the one that is shown in the youtube video. It seems that it is working but for some small problem in the pre-amp section, it is not detecting.

Hi dbanner
I used LF357N I do not know authentic or not authentic LF356P and Tl 018 It does not work Please, what are the best adjustments to work on the beach?

[dbanner]

Hi dbanner
I used LF357N I do not know authentic or not authentic LF356P and Tl 018 It does not work Please, what are the best adjustments to work on the beach?

I refer to the schematic you posted, try jumping C9, it is shown as a 10uF electrolytic capacitor. short out the pins of this capacitor and then power the circuit and see if it is detecting metal.

Remove one leg of D6 and test with meter on diode check. Determine if this diode is good or bad.

Increase R8 to 1K.

Make sure transistor T1 is good.

What transistor did you use for T5? make sure the legs of this FET transistor is correctly inserted into the PCB. Check the datasheet to be sure.

[Vadim18]

@Vadim18,,,,,Do you have a working pcb layout that you wouldn't mind sharing please? Thanks, Marty

Sorry, I have no pcb layout for pi polonets, i even didn't build this project yet. But I have Surf PI, which is a little complicated version of pi polonets.

[MartyJ1963]

Ok Vadim18, No probs,,,,Thank you for the reply. Regards, Marty

[crni1]

I was doing this PCB and here is what needs to be changed to make the detector work fine.

The scheme is ok.

[Andi68]

How do these 2 capacitors, 47pF & 100nF, affect the function of the detector?

[crni1]

by heating the BD911, the detector is unstable.