Serbian "Most Wanted"

[lari]

Phases are ok but the 393 waveform is not good (geb.)

[lari]

Hi Vladimir.
Depth is great.
Discrimination is good.
GEB is bad.
I attach here 2 waveforms.
At first the sinus signal is from pin14 of U1b (ivconic schematic) and the square is from pin10 of 4053. At second photo the sinus is the same and the square is from pin9 of 4053.
What do you see???

Regards

Phases are ok but the 393 waveform is not good (geb.)

[Geo]

Bad configured Geb shows instability when the coil touches the hand, if the instability continues after adjustments Geb attempt setting R8.
Best regards

Hi Vladimir.
Depth is great.
Discrimination is good.
GEB is bad.
I attach here 2 waveforms.
At first the sinus signal is from pin14 of U1b (ivconic schematic) and the square is from pin10 of 4053. At second photo the sinus is the same and the square is from pin9 of 4053.
What do you see???

Regards

[Geo]

[Priloži] 11208 [/ Priloži][quote = Geo; 107.381] Bok Vladimir.
Hvala. Sada je u redu, nema potrebe da se ponovno promijeniti. Ali imam drugi problem. To je vrlo osjetljiv i nestabilan.
Kad ja dodir malo zavojnica ili kabel ili PCB ga oglašava.
Pa ne mogu premjestiti zavojnica na tlu ili na zraku .......
Ideje !!!![/ quote]These are two options for instability (amplification integral round)

Hi Lari.
I connected the capacitor to the sensitivity potentiometer without results.


Regards

[Vladimir]

Hi Vladimir.
Thank you. Now it is OK, no need to change it again. But i have other problem. It is very sensitive and unstable.
When i touch a little the coil or the cable or the pcb it beeps.
So i can't move the coil on the ground or on the air.......
Ideas!!!!

Bad configured Geb shows instability when the coil touches the hand, if the instability continues after adjustments Geb attempt setting R8.
Best regards

[Geo]

[Priloži] 11208 [/ Priloži][quote = Geo; 107.381] Bok Vladimir.
Hvala. Sada je u redu, nema potrebe da se ponovno promijeniti. Ali imam drugi problem. To je vrlo osjetljiv i nestabilan.
Kad ja dodir malo zavojnica ili kabel ili PCB ga oglašava.
Pa ne mogu premjestiti zavojnica na tlu ili na zraku .......
Ideje !!!![/ quote]These are two options for instability (amplification integral round)

Hi Lari, i will try the modifications.
Thank you.

[Geo]

Hi,Geo!How come is very sensitive?My pcb is absolutely stabile,I can touch cables ,shields -no sound at all.What kind of coil do you use?A frend of mine has made SMW -version with 555 audio.I think the sound with it is more beautiful than the last version without 555.And there is best sensitivity.I saw it with DD27 and with sens to min it can detect 20mm coin at 25sm.When sens is to max(he put 470ohms rezistor to prevent high sens)a coin 20mm diameter it can detect at 35sm. But at such a high sens at his home are much inteferences,but on the field test I think this will be the one of the deepest detectors I have evere seen.Also an absolutely mineralized stone -when adjust GEB to this stone it can detect coin over it in discrimination.My pcb with 555 is ready too and soon I will prepare it for field tests.Now there is much snow and I will wait for it to disapear .

Hi Pompey, i also constructed a version with 555 that Lari gave me and it was better, but i made a mistake and reversed the power supply so i burned it. I replaced the IC's and transistors but then never it worked OK. So i came back at this version that i had ready. I want to make the caesar to work with the ready coils that i have. I try it with a Whites Bluemax 15" coil and it detects a 30mm coin at 45..50cm and a soda can at 90..100cm. I don't say exactly the distance because it is very unstable.

Regards

[lari]

[Priloži] 11208 [/ Priloži][quote = Geo; 107.381] Bok Vladimir.
Hvala. Sada je u redu, nema potrebe da se ponovno promijeniti. Ali imam drugi problem. To je vrlo osjetljiv i nestabilan.
Kad ja dodir malo zavojnica ili kabel ili PCB ga oglašava.
Pa ne mogu premjestiti zavojnica na tlu ili na zraku .......
Ideje !!!![/ quote]These are two options for instability (amplification integral round)

[Pompey]

Hi,Geo!How come is very sensitive?My pcb is absolutely stabile,I can touch cables ,shields -no sound at all.What kind of coil do you use?A frend of mine has made SMW -version with 555 audio.I think the sound with it is more beautiful than the last version without 555.And there is best sensitivity.I saw it with DD27 and with sens to min it can detect 20mm coin at 25sm.When sens is to max(he put 470ohms rezistor to prevent high sens)a coin 20mm diameter it can detect at 35sm. But at such a high sens at his home are much inteferences,but on the field test I think this will be the one of the deepest detectors I have evere seen.Also an absolutely mineralized stone -when adjust GEB to this stone it can detect coin over it in discrimination.My pcb with 555 is ready too and soon I will prepare it for field tests.Now there is much snow and I will wait for it to disapear .

[Geo]

Hi Geo
Try to put condenzator of 10n in order to
potentiometer, may be better.

Hi Vladimir.
Thank you. Now it is OK, no need to change it again. But i have other problem. It is very sensitive and unstable.
When i touch a little the coil or the cable or the pcb it beeps.
So i can't move the coil on the ground or on the air.......
Ideas!!!!

[Vladimir]

Hi.
Finally i found the solution of the phase shift between Tx and Rx coil.
I attach the schematic of Caesar, and at left side (in the blue square), you will see the simple modification who corrected the problem.

Regards

Hi Geo
Try to put condenzator of 10n in order to
potentiometer, may be better.

[Geo]

Are you sure of that?

Hi Lari.
Yes i am sure. Maybe the Rx signal is 35o front of the Tx signal and not rear it.
But with the modification that i say, Discrimination is OK.
Maybe tomorrow to try to adjust it better because i have some problems yet. But i began the construction of a Gradiometer so i am busy.

Regards

[lari]

Hi.
Finally i found the solution of the phase shift between Tx and Rx coil.
I attach the schematic of Caesar, and at left side (in the blue square), you will see the simple modification who corrected the problem.

Regards

Are you sure of that?

[Geo]

As i see at Bluemax the Rx signal is about 35degrees rear of the Tx signal. So i must make it to be in phase with tx signal. I will try to late the Rx signal other 330 degrees so to be in phase with the Tx or other 150 degrees and to reverse the winding. But it is not so easy to make it. With the disk potentiometer closed and when i have signal only on the one channel (ferrous), it detect a 30mm coin at 50+cm with the coil no good tuned. This is the reason that i try to make it to work right.

Regards

Hi.
Finally i found the solution of the phase shift between Tx and Rx coil.
I attach the schematic of Caesar, and at left side (in the blue square), you will see the simple modification who corrected the problem.

Regards

[WM6]

No problem if admin banned me ..!!!

Not before you post all LRL schematic here. You will not be so easily pulled out.