Lrl from Italy

[zakari]

Usually the voltage drops down 10mV or more, perhaps you have little gain. Your PCB is double face?

yes sir my pcb is double side

[FrancoItaly]

Hi liudengyuand,

I think there is little amplification because of the universal plate. In fact it is not possible to increase the gain without the stage becomes to self oscillate. As I said it is best to use a double-sided PCB.


Best Regards

[FrancoItaly]

Hi zakari,

Your lrl is OK.

Best Regards

[liudengyuand]

Please tell me, when the hand touch the antenna, the output voltage should probably change from the number of volts to the number of volts?

[FrancoItaly]

The change is not critic, the important thing is that there is a change, if not the cause may be little gain or self osclillation.

[liudengyuand]

Please tell me, when the hand touch the antenna, the output voltage should probably change from the number of volts to the number of volts?

[liudengyuand]

I will design a double-sided pcb, I would like to ask, pcb on both sides of the need for large area copper and grounding? Or only need a large area of negative copper? Thank you

[d4rkh00d]

Hi d4rkh00d,

I'm not in Italy and I don't have the LM3914 display schematic, here I post a generic schematic, with reference to display (3leds) stage you must connect IC1A output to pin5 LM3914, for better adjustment can add between P1 and ground a resistance of 68K (or more).


Best Regards
Attached Images

Thank you very much FrancoItaly

[FrancoItaly]

about 10mV or more, Ie 5.20 to 5.10V or 5.05V.

[zakari]

Hi zakari,

Your lrl is OK.

Best Regards

thanks alot froncoitaly

[FrancoItaly]

Hi liudengyuand,

On one side of PCB you must solder all the components and the other side must be completely covered by copper and it is connected to Ground.

Best Regards

[liudengyuand]

FrancoItaly，thank you

[payam20]

here my pcb files
its 2bl side ( one side as franco said ground )
i put each component where to have the least effect to other one . becuase of its ground it have to much low noise .
what do you think dear franco . need any changes ??
sry for my english Untitled.jpg

[pigeon]

thank you

hi

thank you very much.nice job

[liudengyuand]

payam20，Hello, your PCB is positive and negative are copper? Or only the reverse side of copper? Please answer, thank you