Originally posted by edward
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Lrl from Italy
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i read your help.txt file and all pages of this threat then I made your lrl accurateOriginally posted by FrancoItaly View PostIt is possible that the lrl is not sensitive enough, you followed the instructions of my helps.txt? Did you follow the north / south direction for research? The digital display can be connected to the output of the first operational where the threshold is set.
I found that the output voltage (emitter transistor 5) should be between 4 and 6 volts
Also, the sensitivity is directly related to capacitors c2,c3,c3, When i reduce the amount of these 1pf capacitors, for example, 4 or 5 in series, instead of 3 this will increase the sensivity ( when i touch the antenna the output voltage falls about 0.4 volts and when mobile phone is calling the lrl responds from 50 cm distance)
but the main problem is that by reducing the amount of these capacitors the output voltage falls below 3 volts and this is not in accordance with the instruction
but when i added the antenna amplifire the output voltage does not drop by touching the antenna but the lrl reacts when mobile phone calling from 2 meters
in your opinion how can sensivity be increased without reducing the output voltage???
this is my lrl
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which terminal
hı.franco :which terminal of the lm358(-.+.end put)?thanksOriginally posted by FrancoItaly View Post"supposed target" it is not the best test, you have to bury for example silver objects in a land free from metals, best first pass with the metal detector. After 1 month or more the phenomenon is noticeable.
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Decreasing the total value of C2 / C3 / C4 decreases the output signal but not the gain, then you can have, varying C2 / C3 / C4, for example 3V or 4V or 6V but the gain does not change and therefore the performances are the themselves. It is normal that by adding the antenna amplifier the lrl does not react anymore to the antenna touch, so first you need to calibrate the sensor stage in the original version, then with the antenna connected to the base of TR2 and then connect the antenna amplifier. As I have already said, the antenna amplifier allows you not to push the gain of the sensor stage as much as possible, with the risk of self-oscillation. In fact, the minor amplification will be compensated by the amplifier antenna.Originally posted by edward View Posti read your help.txt file and all pages of this threat then I made your lrl accurate
I found that the output voltage (emitter transistor 5) should be between 4 and 6 volts
Also, the sensitivity is directly related to capacitors c2,c3,c3, When i reduce the amount of these 1pf capacitors, for example, 4 or 5 in series, instead of 3 this will increase the sensivity ( when i touch the antenna the output voltage falls about 0.4 volts and when mobile phone is calling the lrl responds from 50 cm distance)
but the main problem is that by reducing the amount of these capacitors the output voltage falls below 3 volts and this is not in accordance with the instruction
but when i added the antenna amplifire the output voltage does not drop by touching the antenna but the lrl reacts when mobile phone calling from 2 meters
in your opinion how can sensivity be increased without reducing the output voltage???
this is my lrl
http://www.longrangelocators.com/for...1&d=1540651347
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thank you for your reply mr francoOriginally posted by FrancoItaly View PostDecreasing the total value of C2 / C3 / C4 decreases the output signal but not the gain, then you can have, varying C2 / C3 / C4, for example 3V or 4V or 6V but the gain does not change and therefore the performances are the themselves. It is normal that by adding the antenna amplifier the lrl does not react anymore to the antenna touch, so first you need to calibrate the sensor stage in the original version, then with the antenna connected to the base of TR2 and then connect the antenna amplifier. As I have already said, the antenna amplifier allows you not to push the gain of the sensor stage as much as possible, with the risk of self-oscillation. In fact, the minor amplification will be compensated by the amplifier antenna.
i did not notice the self oscillation test ( measuring of output voltage in tr5 emitter)??? should the measurement be with antenna or without the antenna????
With the antenna and without quartz I have 3 volts on the emitter of transistor 5, and when I disconnect the antenna, the voltage is zero.
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The self oscillation test must be with antenna.Originally posted by edward View Postthank you for your reply mr franco
i did not notice the self oscillation test ( measuring of output voltage in tr5 emitter)??? should the measurement be with antenna or without the antenna????
With the antenna and without quartz I have 3 volts on the emitter of transistor 5, and when I disconnect the antenna, the voltage is zero.
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I have 3 volts in output with antenna and without quartsOriginally posted by FrancoItaly View PostYou must increase C13/C14 for more gain.
So the sensor is self oscillation to avoid the self oscillation i need to zero the voltage i should decrease the c13 and c14 (according to help file)
But with decreasing c13 and c14 there is no change in output voltage
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