IDX-PRO+VDI

[Emersonpaz]

After replacing the capacitors, is the board working again?

[Uiliam950]

C8
C10
C16
they are 1uf capacitors and at the time of assembly I got confused and put 1nf capacitors

[Uiliam950]

[surfdetector]

[ATTACH]56175[/ATTACH]
good morning I found 3 more wrong capacitors, these 3 marked in the photo I put 1nf and the project is 1uf I think this is the biggest mistake

Can you post a copy of the schematic that you are using?

[Uiliam950]

good morning I found 3 more wrong capacitors, these 3 marked in the photo I put 1nf and the project is 1uf I think this is the biggest mistake

[Uiliam950]

Hi good morning, I think it is a problem in the metal detector you have assembled, in my experience before soldering the components on the pcb you have to check them with a tool one by one both resistors and capacitors, just a different capacity or resistance can give problems. Now check again all the components you have installed, even the potentiometers that regulate the GB, the TH, the Sens and Discr .. One thing you didn't say the problem you have does it only in all metals or in discrimination?

the problem is with all metals because I can't get any kind of adjustment

[Uiliam950]

what is the function of the 10k VR3 on the board

[Uiliam950]

I think I put this capacitor wrong in the picture it shows 22 n this space means 220 n I think
the correct capacitor is 22n

[dgm]

Hi good morning, I think it is a problem in the metal detector you have assembled, in my experience before soldering the components on the pcb you have to check them with a tool one by one both resistors and capacitors, just a different capacity or resistance can give problems. Now check again all the components you have installed, even the potentiometers that regulate the GB, the TH, the Sens and Discr .. One thing you didn't say the problem you have does it only in all metals or in discrimination?

[Uiliam950]

I noticed that removing the U4 lm393 integrated circuit from the board it stopped bibaring and it worked normally, but with little sensitivity
picking up a cell phone from 20 centimeters I have already put another new lm 393 in its place, but when I put it on the sound starts to crackle again

[Uiliam950]

The coil must be connected to the metal detector once turned on, the RX coil must be blocked and the TX must be superimposed as in the photo sent by you, the measuring instrument must be connected on the two RX wires, and by moving the tx slowly check the voltage in alternating current as low as possible.
Once a voltage of 8 - 15 millivolts has been reached, also block the TX coil.
The coil must have the capacitors connected and the idx turned on.

good night I adjusted my coil at the null point it is at 8 millivolts it has improved the sensitivity a little bit it is taking a cell phone at about 20 centimeters but it still continued with the crackling sound like it was passing some object on the coil

[dgm]

The coil must be connected to the metal detector once turned on, the RX coil must be blocked and the TX must be superimposed as in the photo sent by you, the measuring instrument must be connected on the two RX wires, and by moving the tx slowly check the voltage in alternating current as low as possible.
Once a voltage of 8 - 15 millivolts has been reached, also block the TX coil.
The coil must have the capacitors connected and the idx turned on.

[Uiliam950]

ok but I didn't understand this measurement of the null point it must be found the null point with the coils connected to the pcb and with the pcb connected to the 12v battery?
and I have to measure the coils with the capacitors or without the capacitors

[dgm]

Yes, the coils must be glued one at a time on a surface, then connected to the pcb of the idx they are nulling, once the lowest voltage is reached, the tx coil must also be glued. The slightest variation compromises the nulling, the central part must also be glued, moving it minimally for a nulling closer to zero. I'm from Rome Italy. Try and let me know.

[Uiliam950]

or would i have to do this measurement with 1 digital meter for the rx coil and another digit meter for the rx coil?