Lrl from Italy

[shahrayar]

Now the device was made for what it is
It is not affected by anything strongly, although it is very sensitive

https://www.youtube.com/watch?v=Ch_KAeTcVj0

[shahrayar]

Dear Franco, I want to pack the machine does the aluminum paper affect its quality
Because he fumbles hands

[FrancoItaly]

Dear Franco, I want to pack the machine does the aluminum paper affect its quality
Because he fumbles hands

Even with shielding, the lrl is sensitive, even if to a lesser extent, to the human body, also holding the handle with both hands increases sensitivity.

[shahrayar]

Thanks dear Franco, it is
Is this true?

[FrancoItaly]

Thanks dear Franco, it is
Is this true?

the scheme is wrong, R7 must be removed, it is not in my scheme.

[shahrayar]

I know dear Franco Thank you

[shahrayar]

Dear Franco, I read a lot of comments about the device, there are those who say that the device is affected by the sky, and another says that it is affected by the north and the earth
My device is not affected only by the hands and a few devices up close
I do not understand
Please some clarification

[shahrayar]

Hi darkman,

The values seem correct, the correct value of sensitivity is a bit less than the beginning of the compass effect. Have you tried this test? If you are unable to have this effect means that there is not enough amplification. This is confirmed by the fact that you are using 6.6pF for C2, C3 and C4, typically this value is about 1pF. Also for the gain of the stage it is the rule that maximum gain is before the stage starts to self oscillate. Controls the gain of TR2, TR3 and Tr4, beta must be 500 or higher, try to lower the value of R10-R12 from 1K to 560 ohms or less. Of course there is also the possibility that the buried metal not issue the "phenomenon."

Best regards

Yes, the solution is to reduce resistance 10 and 12

[shahrayar]

Resistance reduction 10 and 12 did not work
The device has lost its sensitivity
Is there a solution, Sir Franco to sense the compass?

[FrancoItaly]

Resistance reduction 10 and 12 did not work
The device has lost its sensitivity
Is there a solution, Sir Franco to sense the compass?

The sensor stage having a high amplification is very critical, I have always suggested to make a pcb only for the sensor stage, with double face and with the lower face connected to ground, this to avoid the danger of self oscillation. I still recommend making the original sensor stage first, that is without the antenna amp and setting it up. The compass effect and the sky effect appear when the amplification is excessive, but to be sure that the total gain is sufficient the lrl must be able to reveal it. If the sensor stage enters self-oscillation before obtaining the compass effect, then its amplification will be insufficient. The transistors must be of the BC183C or BC549C type or others with a gain greater than 500.

[shahrayar]

That is, a copper plate connected to the ground should be placed under the sensor

[shahrayar]

I placed a copper plate below the sensor and connected to the ground
Although the copper plate is about 0.5 cm away from the sensor board
The device senses the metal at a distance of 20 cm
But when the value of the two resistors 10 and 9 is reduced, the device becomes not sensitive

[FrancoItaly]

I placed a copper plate below the sensor and connected to the ground
Although the copper plate is about 0.5 cm away from the sensor board
The device senses the metal at a distance of 20 cm
But when the value of the two resistors 10 and 9 is reduced, the device becomes not sensitive

the copper plate must be adherent and under the sensor stage pcb, it must have the same dimensions as the pcb, the best thing is to use a double-sided pcb.

[shahrayar]

Thank you, Sir Franco
I did it, the device sensed the walls, it sensed the large metals as well, but I didn't try to reduce the resistors R9 . R10
The device senses my hand from about 20 cm from the antenna
But all this sensitivity can be eliminated by changing the resistance 22K

[shahrayar]

Demo video , R9 AND R10 =1K

https://www.youtube.com/watch?v=Um8UdWFSJJQ

Now when I made the resistors 9 ,10 =680 OHM it became more sensitive and stable