Lrl from Italy

[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]

Originally Posted by FrancoItaly

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]

Originally Posted by 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?

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]

Originally Posted by 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

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

[shahrayar]

Regarding the transistor 548 why it is not suitable for this device؟, the frequency of 200 MHz

[shahrayar]

Thank you for your cooperation Dear Franco, I forgot to thank you,
I was busy with the many devices that I made

[FrancoItaly]

Originally Posted by shahrayar

Regarding the transistor 548 why it is not suitable for this device؟, the frequency of 200 MHz

I think any transistor BC...C is suitable.

[shahrayar]

Thanks dear Franco, you are a very nice person
What do you think of this amendment?
https://www.youtube.com/watch?v=680zTzg80Uk

[shahrayar]

Maybe this is better than crystal

[FrancoItaly]

Originally Posted by shahrayar

Thanks dear Franco, you are a very nice person
What do you think of this amendment?
https://www.youtube.com/watch?v=680zTzg80Uk

think that's ok.

[FrancoItaly]

Originally Posted by shahrayar

Maybe this is better than crystal

I chose the quartz version because it is much simpler and just as effective, in fact there are fewer components, you can easily change the frequency only by changing the quartz and oscillating more easily.

[shahrayar]

Originally Posted by FrancoItaly

think that's ok.

[shahrayar]

Sir Franco, I have set up a transmitter antenna, and another for reception . Frequency 10 MHZ
What do you think this way?
https://www.youtube.com/watch?v=zmq4-ODVXuA

[FrancoItaly]

Originally Posted by shahrayar

Sir Franco, I have set up a transmitter antenna, and another for reception . Frequency 10 MHZ
What do you think this way?
https://www.youtube.com/watch?v=zmq4-ODVXuA

My lrl operates in the range of 100Mhz, the frequency of the internal oscillator is in the range 2 -10Mhz (approximately) and does not intervene directly in the reception of the "phenomenon". However the only way to verify the goodness of your change is on the test field, with buried metals.

[shahrayar]

Originally Posted by FrancoItaly

My lrl operates in the range of 100Mhz, the frequency of the internal oscillator is in the range 2 -10Mhz (approximately) and does not intervene directly in the reception of the "phenomenon". However the only way to verify the goodness of your change is on the test field, with buried metals.

I have used 10 MHz transmitter and 10 MHz receiver by adjusting the coil variable
the frequency of the internal oscillator is in the range 10Mhz
I understood from your saying I could use reception up to 100 MHz

[shahrayar]

Dear Franco
What do you think of this oscillator?

[IMG][/IMG]

[IMG][/IMG]

[FrancoItaly]

Originally Posted by shahrayar

Dear Franco
What do you think of this oscillator?

[IMG][/IMG]

[IMG][/IMG]

I don't know what to say, at first sight it seems to me too complicated and not always what works in theory in a simulation in reality works just as well.

[shahrayar]

Yes it does not work in simulation

[shahrayar]

Finally, I found an effective circuit simulator