Lrl from Italy

[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]

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]

Help

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

[abdou2014]

Display 1 Led

[abdou2014]

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 ?