Lrl from Italy

[FrancoItaly]

Originally Posted by Milad.salsa

Hello Mr. Franco When we want to measure the self-oscillation of the circuit, we remove the crystal from the circuit and adjust the potentiometers p3 and p2. Should the antenna be connected or disconnected?

The antenna must be connected.

[FrancoItaly]

Originally Posted by Zicos

i made another sensor to see what happens... and it has the same problem. when i touch the antenna the output voltage does not drop or rise it is stable... i use BC548c.. i used that antenna i have and the sensor output voltage is always 0volt without crystal.. with crystal it is 5.44volt with only one capacitor c2(1pf) .if i remove c2 the output voltage is 4v if i remember correctly... that way the output voltage drops when i touch the antenna..

You talk about antenna amplifier, I'm referring to the original version which doesn't have it.

[abdou2014]

Hello dear friend Franco, I want to know if your LRL works after a rain ?

[Zicos]

.....in the 8mhz sensor..... (1)....in the calibration I used a piece of copper wire 40 cm without reinforcement (as I had it in the photo) and with a crystal the output voltage is 5.44 volts, when I touch the antenna the output voltage does not drop or rise it is always constant 5.44 volts.........(2) ......also (without crystal and with connected antenna without amplifier as in the photo the output voltage it's always 0 volts).....(3)....when i touch the antenna why doesn't the output voltage change????? what do you think is wrong????

[Zicos]

Do you understand what the problem is? is the translation good or not?????

[FrancoItaly]

Originally Posted by abdou2014

Hello dear friend Franco, I want to know if your LRL works after a rain ?

I don'tknow.

[abdou2014]

Thank you .

[FrancoItaly]

I have to admit I'm a little confused, let's recap.
1- with the antenna (piece of wire) connected and with the oscillator disconnected (disconnect C2) increase amplification (increase C13/C14 or decrease R10/R12) until self-oscillation is obtained (there must be a stable signal of a few V (not critical) which does not change by touching the wire.
2- decrease the amplification until you get 0V at the output.
3-connect C2, find the correct value that gives 4-6 V output
Check the gain of the transistors, it must be greater than 500, I happened to measure BC...C transistors with gain less than 500.

[Zicos]

thank you very much Mr. Franco.

[Zicos]

good morning mr franco and everyone. how are you??? be always well.

[FrancoItaly]

Originally Posted by Zicos

good morning mr franco and everyone. how are you??? be always well.

I'm fine, I hope the other members of the forum are too, I think that at the moment there are more important things to take care of, the forum should be considered a pastime and a way to meet other people.

[Zicos]

You are right.

[Kazem]

Hello, dear Mr. Franco
Thank you very much for providing the magic plan, my question is whether sky effect and polar effect are similar or what is their difference, is the border of sky effect and polar effect the measure of efficiency. Thank you very much

[Kazem]

Another question, is it possible to connect the shield to the antenna through a separate inductor and capacitor and use the ambient waves as a transmitter? Thank you very much.

[Kazem]

I,m sory

[Kazem]

Something has confused me. When I connect the internal inductor 2 turns to the ground and to the antenna and the external inductor 3 turns to the c10 capacitor with high circuit gain, I don't have a polar effect, but the effect of the sky is very strong, and the test with a copper tray buried in 2.5 meters for 12 years It hunted, but I don't have a radius. The antenna must be buried on the metal to do the sense.

[FrancoItaly]

Originally Posted by Kazem

Another question, is it possible to connect the shield to the antenna through a separate inductor and capacitor and use the ambient waves as a transmitter? Thank you very much.

I don't know, we should try, but first of all it's better to make the original version.

[FrancoItaly]

Originally Posted by Kazem

Hello, dear Mr. Franco
Thank you very much for providing the magic plan, my question is whether sky effect and polar effect are similar or what is their difference, is the border of sky effect and polar effect the measure of efficiency. Thank you very much

Both the sky effect and the compass effect are due to excessive gain, so the only remedy is to decrease the sensitivity.

[FrancoItaly]

Originally Posted by Kazem

Something has confused me. When I connect the internal inductor 2 turns to the ground and to the antenna and the external inductor 3 turns to the c10 capacitor with high circuit gain, I don't have a polar effect, but the effect of the sky is very strong, and the test with a copper tray buried in 2.5 meters for 12 years It hunted, but I don't have a radius. The antenna must be buried on the metal to do the sense.

I advise you to make the original version with 1 coil, I think you are the only one who made it.

[Kazem]

Dear Mr. Franco, thank you for your answer, another experience I had was several different types of antennas, including the diameter of one centimeter and less, all of which were up to one meter. Some antennas receive the polarization effect very little, is this good or is it possible that it is weak in receiving the phenomenon The main point is that if the antenna does not absorb the polarizing effect, it will be weak in absorbing the phenomenon, and will it affect the amplification gain of the circuit?

[Kazem]

Yes, I have made both a single inductor and two inductors. Do you think it is better to use the same coil as the original design because of matching the impedance of the antenna with the circuit?

[FrancoItaly]

Originally Posted by Kazem

Dear Mr. Franco, thank you for your answer, another experience I had was several different types of antennas, including the diameter of one centimeter and less, all of which were up to one meter. Some antennas receive the polarization effect very little, is this good or is it possible that it is weak in receiving the phenomenon The main point is that if the antenna does not absorb the polarizing effect, it will be weak in absorbing the phenomenon, and will it affect the amplification gain of the circuit?

I don't know the answer, I'm not a physicist, we need to experiment. I propose the coil antenna which has approximately the same sensitivity as the stylus antenna, it has the disadvantage that it cannot be modified like the stylus antenna which can be lengthened.

[FrancoItaly]

Originally Posted by Kazem

Yes, I have made both a single inductor and two inductors. Do you think it is better to use the same coil as the original design because of matching the impedance of the antenna with the circuit?

I'm not very familiar with RF, so I can't answer you, the version with the two coils and the one with the amplifier improve the sensitivity slightly, but I don't know if it's worth it. The 20 MHz version is the one that significantly increases the gain, as R1/C10 is tuned to a 20 MHz harmonic, making the TR2 mixer more efficient, but as I said it is very critical to tune. Out of three lrls I've built only one works well, so I'm unable to help with the construction.

[erfan]

Hello dear Franco
I have been using your circuit for years and have had amazing results.
Now I have a question. As we know your circuit works in the FM frequency range. Do you think if we change this range to AM SW MW or etc.. will we still get reactions similar to the reaction of the device to precious metals?
i very much apreciate if you share your comment in detailed explanation (if possible) ofregarding of how the various radio frequencies work in your circuit.
Thank you.

[FrancoItaly]

Originally Posted by erfan

Hello dear Franco
I have been using your circuit for years and have had amazing results.
Now I have a question. As we know your circuit works in the FM frequency range. Do you think if we change this range to AM SW MW or etc.. will we still get reactions similar to the reaction of the device to precious metals?
i very much apreciate if you share your comment in detailed explanation (if possible) ofregarding of how the various radio frequencies work in your circuit.
Thank you.

The only way to know is to try with different frequencies, several years ago I tried different values for L1/C10, L1 with 2 or 3 turns, C10 with 30 or 22 or 10 pF or nothing (only the parasitic capacitance of the B/ And of TR2), the result was more or less the same for all combinations, we are in the 80/120 MHz range.
Since several members on the forum ask about the performance in the field, could you list some of them?