Lrl from Italy

[sakher]

thank you veary much Francoitaly and Dream man

[FrancoItaly]

I have not tried the dream man version, here I post my original PCB surely working. The components are soldered on copper side. I want to remember that it is a high-gain stage and the need to avoid self oscillation.

[dream_man]

Originally Posted by FrancoItaly

this is the pcb by Dream man who really did a good job.

Thanks dear Franco for compliments.
It needs couple of minutes to look at the PCB which I drawn and its quite clear that I just made a copy of your pcb. So it works well as I made and its working properly but never tried in the field yet.

[dream_man]

Originally Posted by sakher

thank you veary much Francoitaly and Dream man

your welcome sakher

[AurumKid]

Hi Taxma

What is the maximum range of detection for the copper coin you found?

Hello Sir Franco

Is it posible to increase the depth range for deeper target for example 5meters deep buried gold bar?

Regards

[FrancoItaly]

I think the only way to increase the range is to increase the gain but this can only be done if you do not see the compass effect. However, I think that gold buried for a long time is detectable at a distance greater than one piece of copper of the same volume.

[abdou2014]

can we isolate the sensor from the compass effect and receive only the target field Mr franco ?

[FrancoItaly]

I do not know, but it could be that the "phenomenon" is part of the compass effect, there may be an ion channel on the north / south direction and a buried metal may vary locally the amplitude of this flow. In that case there would be no possibility of eliminating the compass effect.

[abdou2014]

if the "phenomenon" is part of the compass effect and we don't must increase the sensitivity until the compass effect , in this case we can't detect the phenomenon, unless the phenomena is manifest before the compass effect , please How far we lower the sensor from the beginning of the compass effect for detect the phenomenon ?

[FrancoItaly]

as I said you have to adjust the gain until you see the compass effect, then reduce it until the disappearance of the compass effect. If my theory is true then the "phenomenon" increases the compass effect in the vicinity of the target and can be revealed from the LRL. By varying the gain you get a kind of ground exclude.

[abdou2014]

Can i do this setting with the threshold potentiométer ( i fixed the gain with a resistor ) or it must be with the gain ?

[FrancoItaly]

Yes you can do this setting by threshold potenziometer.

[sakher]

Can I replace the display stage with frequency counter?

[FrancoItaly]

no, the output of sensor stage is a DC voltage.

[abdou2014]

who is the Fine and accurate adjustment , threshold or gain ?

[zakari]

hi francoitaly

why have you made pcb of the sensor and display stage seperatly?

i am thinking one of the your secretes is that.

what about you?

[AurumKid]

Originally Posted by FrancoItaly

I think the only way to increase the range is to increase the gain but this can only be done if you do not see the compass effect. However, I think that gold buried for a long time is detectable at a distance greater than one piece of copper of the same volume.

I think compass effect is hard to eliminate. Maybe some modification to the circuit or increase the gain as you said will do.

Thank you Sir Franco

[zakari]

I belive the increase gain isnt useful because detect the compass effect we can also amplify the phenomenon of target
do you remember that morgan said tv amplify the phonemenon

perhaps we can amplify the phenomenon with vhf frequence and high voltage

[abdou2014]

Mr franco ,who is the Fine and accurate adjustment , threshold or gain ?

[FrancoItaly]

The best thing is to act on the gain, the threshold is for fine-tuning. I think that it is better to use two separate PCB for sensor stage and display stage, to avoid couplings parasites that might trigger self oscillations. If this were to happen it would not use the maximum gain for the sensor stage.

[abdou2014]

Thank you Mr Franco , you helped us a lot , the separation pcb enough or we must also separate the power supply ,each stage has its battery ?

[FrancoItaly]

No, just a single power supply, but each stage must be decoupled as shown in the wiring diagram. C5, C6, R4 for the oscillator stage and C7, C8, R5 to the amplifier stage.

[sakher]

is there any PCB for only display stage that you see it suitable?
and Thank you so much.

[abdou2014]

Display 1 Led

[abdou2014]

Originally Posted by FrancoItaly

The best thing is to act on the gain, the threshold is for fine-tuning. I think that it is better to use two separate PCB for sensor stage and display stage, to avoid couplings parasites that might trigger self oscillations. If this were to happen it would not use the maximum gain for the sensor stage.

how to know that is a self oscillator , in any case the LED lights by increasing the potentiometer ?