Lrl from Italy

[JHERICKU]

Hi there Jeg do you pcb on the sensorof 8mhz?can u share?I built the display and the two leds lights when I turn on theswitch..Is it normal? even I turn the potentio meter there isno changes at all..I wish to measure the output of the display stage with multimeter..which pin of IC to check?Thank u in advance..

[Jeg]

Hi there Jeg do you pcb on the sensorof 8mhz?can u share?I built the display and the two leds lights when I turn on theswitch..Is it normal? even I turn the potentio meter there isno changes at all..I wish to measure the output of the display stage with multimeter..which pin of IC to check?Thank u in advance..


My friend, i never use ready pcb drawings as i do it for experimentation. I usally make them in ready test pcb boards like in the pic.



i used the circuit of 20MHz drawing with the trimmers.



No its not normal. You should be able to adjust your output so to light just the first led.
You have two pots for the device. One for the differential amplifier and one for the gain. The first one is the most important. Personally i have omitted the gain pot and i fixed my device to the maximum gain which is something like 6 times. The first pot will take your output down to minimum levels so only one led will light.

[JHERICKU]

waht do u think is better?8 mhz or 20? did you also use double face pcb on 8mhz version?I think I will back again from the start..any way this display pcb I used..

[JHERICKU]

I dont know who owns this pcb on display..I
This isthe one I have used but when I turn on the switch..the two leds lights continuously even I turn the potentiometer..Can any one help me..Thanks..

[JHERICKU]

hello Ealk man Can I used value of crystal aside from 20mhz?Is it ok for 16,10 or is it only for 20mhz?thank u in advance..

[Jeg]

prototype pcb board with copper plates isolating oscillator

[Jeg]

waht do u think is better?8 mhz or 20? did you also use double face pcb on 8mhz version?I think I will back again from the start..any way this display pcb I used..


The circuits are essentially the same. I went with the 20MHz one as it also has trimmers for adjusting gain. I used 16MHz

Output of sensor before diff 4,5-5,5V

[JHERICKU]

For those who want to try.
Enjoy it. :):)

hello friend walkman,BC...c type transistors are not available in our locality..Can I use Bc...b type with this 20mhz design?What can u suggest if I will put the circuit on an aluminum box?does it affect its sensitivity?Also if I do mot have available 20mhz crystal,What value can I use?Did u manage to remove self oscillation?Thank u in advance..

[FrancoItaly]

I dont know who owns this pcb on display..I
This isthe one I have used but when I turn on the switch..the two leds lights continuously even I turn the potentiometer..Can any one help me..Thanks..

I am attaching the new display stage again, however if the sensor stage output is too high, the threshold cannot be adjusted, so it is necessary to decrease it.

[JHERICKU]

Hi friend,
Please read Francoıtaly 110.page #2732 in message; 20mhz component and help files

I used for frcanco 8mhz aluminum box.Very stable.

My youtube channel videos

https://www.youtube.com/channel/UCG36SfjYfTt48nJUI_lXauQ/videos

Good Luck.
Thank u friend walkman for the response..I only have bc...b type transistor..do u think I can make it successfull with with the 8mhz? also can I use different value of potentiometer?Does it affect the performance of the circuit?

[JHERICKU]

prototype pcb board with copper plates isolating oscillator

hi Jeg..Very nice output..what value of variable capacitor and potentiometer did u use?is that the 20mhz version or 8?.I was thinking I will use the pcb of walkman but I will try 4mhz crystal for the meantime until I can find 20mhz and change it..What can u suggest?

[Jeg]

hi Jeg..Very nice output..what value of variable capacitor and potentiometer did u use?is that the 20mhz version or 8?.I was thinking I will use the pcb of walkman but I will try 4mhz crystal for the meantime until I can find 20mhz and change it..What can u suggest?

Hey Jh
Franco have said that 20Mhz crystal brings instability. I used a 16MHz one.
Capacitor is something between 4-120pF. It is the common cap that we use in radio receivers.

ps. Attached is the differential i used. The minimum voltage that you can achieve at the output is 1.3V. Your first led starts lighting at 2V. (Approximate values)

[JHERICKU]

Thank you jeg for the response..I will try ur display with volt meter..

[JHERICKU]

prototype pcb board with copper plates isolating oscillator
Hi there Jeg..I cannot see any ic in ur prototype..Did u not not use any IC?Is that the display only?

[Jeg]

It is on a second board my friend and i used an lf353 opamp. I ll find some time to take a pic from inside.

[FrancoItaly]

It is on a second board my friend and i used an lf353 opamp. I ll find some time to take a pic from inside.

lf353 op amp is not suitable because it must be powered with split voltage, it takes the LM358.

[Jeg]

Thanks Franco.
Due to the fact that both of its inputs are positive, i don't really see any malfunction other than i can't take the output to zero level. But i'll test 358 to see the difference.:)

[Jeg]

Franco, have you ever tried to use a second vertical antenna for emission? There must be a way to increase the distance of research. In a next build, instead of connecting oscillator to the input antenna, i'll feed the input through a second vertical antenna coupling. I am very curious!:)

[Jeg]

I tested lm358 and now the output of diff can go down to zero. Thanks Franco

JH the inside boards. The pink one is a dc to dc boost converter for 2.5 euros. It takes the 3,7V of the battery to 16V and then i drive with that my regulators.

[FrancoItaly]

I tested lm358 and now the output of diff can go down to zero. Thanks Franco

JH the inside boards. The pink one is a dc to dc boost converter for 2.5 euros. It takes the 3,7V of the battery to 16V and then i drive with that my regulators.

The DC / DC converter generates disturbances, since it is in practice an oscillator, in high gain circuits it can be a problem, I suggest to use 2 batteries in series of 9 V, since the absorption is a few tens of mA.

[Jeg]

The DC / DC converter generates disturbances, since it is in practice an oscillator, in high gain circuits it can be a problem, I suggest to use 2 batteries in series of 9 V, since the absorption is a few tens of mA.

Nice point thank you. Thankfully in this case i don't experience any interference from converter. Probably due to the aluminum box which is grounded and the distance from receiver transistors. Next time i will encase it in a faraday shield.:)

ps. with this battery i can work at least ten hours before charging while it also powers this led voltmeter which is a demanding load.

[kaveh]

Hello everyone and Mr. Franco. Mr. Franco, I am using a 14.7456 MHz crystal. How do I know what a good harmonic setting is for the c10 capacitor? When I turn the c10 trimmer, the output voltage of the sensor reaches its maximum in one place and the lowest in another. Where is the good harmonic?

[JHERICKU]

Anyone has the pcb of sensor stage from 8mhz..?The one that is ready to print but only the sensor stage..Thank u in advance..

[JHERICKU]

I have here already the sensor stage circuit but the problem is some labels are not readable..it was overlayed by the lines..Foes anyone have a better circuit?Thank u..

[Jeg]

Hey Jh
Print the circuit and the board drawing and compare them to find out the components. If you have problems then put in a red circle what you need to know, and help will arrive.:)
ps. Why don't you use the other circuit with the trimmers?

[FrancoItaly]

Hello everyone and Mr. Franco. Mr. Franco, I am using a 14.7456 MHz crystal. How do I know what a good harmonic setting is for the c10 capacitor? When I turn the c10 trimmer, the output voltage of the sensor reaches its maximum in one place and the lowest in another. Where is the good harmonic?



It's ok when the output voltage of the sensor stage reaches its maximum.

[hoshi]

Hi dear friend Mr jeg
Your plan will not work properly

[Jeg]

Hi dear friend Mr jeg
Your plan will not work properly

Hi hoshi
What do you mean my friend? Its a simple differential amplifier.

https://www.electronics-tutorials.ws/opamp/opamp_5.html

[JHERICKU]

hello to all and to friend franco..I tried the 8mhz circuit display with 1led..Can u advice me if I got the correct output?when I turned on the potentiometer with the trimmer maximum I got 4 or 5.+ volts on resistor which connecting to sensor stage.When I connect the multimeter probe the beep and led goes off after I removed it the buzzer and keds on again...What do u think Franco?
Ps. The buzzer and led high and low when turning the potentiometer and trimmer..

[JHERICKU]

Hey Jh
Print the circuit and the board drawing and compare them to find out the components. If you have problems then put in a red circle what you need to know, and help will arrive.:)
ps. Why don't you use the other circuit with the trimmers?
I used it already Jeg..When I measured the output on resistor connecting on sensor stage,I got 4/5+.volts and the bezz and leds off..When I remove the test probe the buzz and leds goes on again..Do u think I got the correct output on display?
Ps..I used the display with 1 led..

[Jeg]

Hi Jh


Your voltage levels at sensor's output look that they are normal.
Assuming that your circuit is correct, then try the following.


When your voltmeter is connected alter your potentiometer to adjust again the buzzer/led threshold. Normally you will be able again to turn on your led.


Find a way to firm your meter's probes on the right points and then move your hands away to see if there is a variation on numbers. Then attach antenna with your hand and confirm that the output voltage drops down.



In general, device interacts with your body as it uses it to close the circuit between device and earth. Your hand acts as a capacitor plate. When you adjust your device your hand has to be firm and steady attaching the handle of your device or your aluminum box.


Regards

[JHERICKU]

Hi Jh


Your voltage levels at sensor's output look that they are normal.
Assuming that your circuit is correct, then try the following.


When your voltmeter is connected alter your potentiometer to adjust again the buzzer/led threshold. Normally you will be able again to turn on your led.


Find a way to firm your meter's probes on the right points and then move your hands away to see if there is a variation on numbers. Then attach antenna with your hand and confirm that the output voltage drops down.



In general, device interacts with your body as it uses it to close the circuit between device and earth. Your hand acts as a capacitor plate. When you adjust your device your hand has to be firm and steady attaching the handle of your device or your aluminum box.


Regards
Hi Jeg.I am not yet on sensor stage..The voltage I got is from the display circuit,the R10 from ic3a pin3..I will try to finish the sensor stage today..
ps..I do not have voltmeter so I used the 1 led display..

[FrancoItaly]

Hi Jh


Your voltage levels at sensor's output look that they are normal.
Assuming that your circuit is correct, then try the following.


When your voltmeter is connected alter your potentiometer to adjust again the buzzer/led threshold. Normally you will be able again to turn on your led.


Find a way to firm your meter's probes on the right points and then move your hands away to see if there is a variation on numbers. Then attach antenna with your hand and confirm that the output voltage drops down.



In general, device interacts with your body as it uses it to close the circuit between device and earth. Your hand acts as a capacitor plate. When you adjust your device your hand has to be firm and steady attaching the handle of your device or your aluminum box.


Regards

I state that the calibration inside the laboratory is difficult due to the many disturbances and the calibration must be done with the antenna inserted. Once the right value at the sensor stage output has been established, it connects to the display stage and any measurements, if the LEDs do not light up by varying the threshold, then the controls must be done on the display stage. If you want to measure the output on the collector of TR4 with the oscilloscope, the signal at the sensor stage output goes to zero.

[JHERICKU]

Thank u franco..I will finish the sensor stage today and update u so soon..Thank u..

[Jeg]

Hi Jeg.I am not yet on sensor stage..The voltage I got is from the display circuit,the R10 from ic3a pin3..I will try to finish the sensor stage today..
ps..I do not have voltmeter so I used the 1 led display..


There is a communication barrier my friend. When you finish your sensor with the antenna in place we talk again.


Tnks Franco

[Jeg]

If you want to measure the output on the collector of TR4 with the oscilloscope, the signal at the sensor stage output goes to zero.


Why is that Franco? I don't remember noticing this. Oscilloscope has a high input impedance.

[FrancoItaly]

Why is that Franco? I don't remember noticing this. Oscilloscope has a high input impedance.

The oscilloscope has 1M impedance with few picofarads, however this is what happens, this shows how sensitive and critical the sensor stage is.

[JHERICKU]

There is a communication barrier my friend. When you finish your sensor with the antenna in place we talk again.


Tnks Franco
Hell Jeg..I have finish both the display and sensor..When I turn on there is a tiny sound coming from the buzzer..when I turn the potentiometer and trimmer there is no effect..no buzz and leds on only the tiny sound from the buzzer..

Ps.I used Bc547b,10k potentiometer trimmer..
where should I put the test probe to measure the output dc?
Thank u in advance..

I am sorry for my badproject..I am not an electronic eng noraquire formal education about electronic..I badly meeding this device so I am trying my best build..

[Jeg]

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.:)


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)

[FrancoItaly]

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.:)


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)

Yes, otherwise it could mean that there is a self oscillation. By touching the antenna a part of the signal on the base of TR2 (the mixer) is absorbed by the body and therefore the signal amplified by the sensor stage decreases slightly.

[JHERICKU]

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.:)


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)
I do not know where to put the test probe to measure the voltage..I have have no idea if it is droping or not..

This time I change te 10k potentiometer with 25k and remove the sensor stage for a while but there is no buzz and led ligths at all..I have noticed that when I touched everywhere on the board the led and buzzer beeps also..I think it is grounded..
Any suggestions my friend..

[FrancoItaly]

I do not know where to put the test probe to measure the voltage..I have have no idea if it is droping or not..

This time I change te 10k potentiometer with 25k and remove the sensor stage for a while but there is no buzz and led ligths at all..I have noticed that when I touched everywhere on the board the led and buzzer beeps also..I think it is grounded..
Any suggestions my friend..

The point to be measured is the output of the sensor stage, the one that goes to the input of the display stage. For the rest I don't know what to say, check the assembly carefully, maybe you made some mistakes.

[JHERICKU]

hello friend franco,Should I connect the negative probe of the multimeter to ground and the positive one to antenna to get the reading or the positive probe to transistor 04 emitter ?

I am so sorry..I have few knowledge about electronics..My apologies..

[JHERICKU]

The point to be measured is the output of the sensor stage, the one that goes to the input of the display stage. For the rest I don't know what to say, check the assembly carefully, maybe you made some mistakes.
I put the probe on sensor output and I got 4.+volts. I touched the antenna and the voltage is thesame..why should I do?

[FrancoItaly]

hello friend franco,Should I connect the negative probe of the multimeter to ground and the positive one to antenna to get the reading or the positive probe to transistor 04 emitter ?

I am so sorry..I have few knowledge about electronics..My apologies..

The negative probe of the multimeter to ground and the positive to transistor 04 emitter.

[JHERICKU]

The negative probe of the multimeter to ground and the positive to transistor 04 emitter.
I got 1.5 volts on transistor04 emitter with the trimmer on maximum..I have noticed that it beeps when I touched the board or the potentiometer and the antenna but the output not dropping..I believed the antenna is on positive line.It gives me 12v measurement..

[JHERICKU]

I remove the quartz and I got .044 volts on output..Can anyone have idea especially to franco if I got the correct output?
ps.I used 4mhz quartz..
Thank u for suggestions in advance..

[Rubin]

I would like to know who knows or has tested, if the franko circuit can detect nuggets.
I ask, because i have many signals from a place and i find only small nuggets.
I am comfused

[FrancoItaly]

I remove the quartz and I got .044 volts on output..Can anyone have idea especially to franco if I got the correct output?
ps.I used 4mhz quartz..
Thank u for suggestions in advance..

The sensor stage output measurement is on the emitter of TR5, not TR4.

[FrancoItaly]

I would like to know who knows or has tested, if the franko circuit can detect nuggets.
I ask, because i have many signals from a place and i find only small nuggets.
I am comfused

In theory, if the nuggets have been in that place for long enough, they should generate the phenomenon. The unknown is the size, I don't know if so small they emit a sufficient signal. The other explanation is that there are metals buried deeper than the range of the MDs and this may have happened in your case.

[Jeg]

I don't know if so small they emit a sufficient signal.

Obviously they do emit such a signal as rubin found them and your receiver can get it.

Rubin, what is the distance approximately that you hit them, and what is your crystal's frequency if you don't mind?

[Rubin]

Obviously they do emit such a signal as rubin found them and your receiver can get it.

Rubin, what is the distance approximately that you hit them, and what is your crystal's frequency if you don't mind?


With 8mHZ crystal the distance is 3 meters. With 16MHz crystal the distance is shorter
The spot has small stones with nuggets.
I do not know what is happening, so I asked if anyone has tried to let me know

[Jeg]

With 8mHZ crystal the distance is 3 meters. With 16MHz crystal the distance is shorter


Great observation Rubin. Thank you.
I wonder if a 1Mhz can increase this distance more.

[JHERICKU]

Hello to all..I got 4.706volts on tr05 emitter..when I touched the antenna,the voltage doesnt drop but increases to 4.711volts instead..Anyone can advice me..especially to franco..thank u in advance..

[FrancoItaly]

Hello to all..I got 4.706volts on tr05 emitter..when I touched the antenna,the voltage doesnt drop but increases to 4.711volts instead..Anyone can advice me..especially to franco..thank u in advance..

Touching the antenna is a test to determine if the sensor stage amplifies, if the signal increases instead of decreasing I don't think it's a problem, the real test is on the ground.

[FrancoItaly]

With 8mHZ crystal the distance is 3 meters. With 16MHz crystal the distance is shorter
The spot has small stones with nuggets.
I do not know what is happening, so I asked if anyone has tried to let me know

Has the 16 Mhz version been tuned on a harmonica? With this device the sensitivity is higher because the mixer has a higher efficiency. I don't think the oscillator frequency is very important, because the frequency on which the phenomenon acts is in the FM range. However, it may be that the sensor stage amplifies more at a lower frequency.

[Rubin]

[QUOTE=FrancoItaly;161517]Has the 16 Mhz version been tuned on a harmonica?

Correct!!
As you say the frequency is not important, but I think detector don't working if oscilator has crystal <4MHZ.
Anyway, I changed all the components in the alarm section with 10 led as a voltmeter. In this case it works better.
Maybe the first part of the preamplifier has more gain and the circuit can detect rocks with nuggets. The circuit now can detect ghost targets,in practice dont working on real targets. So the next time I try to put the gain on first section lower.
We see..

[Jeg]

[QUOTE=FrancoItaly;161517]Has the 16 Mhz version been tuned on a harmonica?

The circuit now can detect ghost targets,in practice dont working on real targets. So the next time I try to put the gain on first section lower.
We see..

Do you consider gold nuggets as ghost targets? You should realise that this device catches a physical effect and not metals. You are lucky if you catch GOLD nuggets and not iron. Sooner or later you will bumped on to something more valuable. :-)

[Rubin]

[QUOTE=Rubin;161518]

Do you consider gold nuggets as ghost targets? You should realise that this device catches a physical effect and not metals. You are lucky if you catch GOLD nuggets and not iron. Sooner or later you will bumped on to something more valuable. :-)
I'm not saying nuggets of gold , that's your conclusion
I said nuggets on metal stones unknown to me.
Therefore, the extracted soils can be detected as targets.
In this case maybe need a gain for reject any external parasitic signal as stones

[Jeg]

Sorry. Since yesterday i thought that you were talking about gold nuggets. So you can excuse my surprise:lol:

ps. Think again the second suggestion of Franco about a real target somewhere there before going for modifications.

[Rubin]

Sorry. Since yesterday i thought that you were talking about gold nuggets. So you can excuse my surprise:lol:

ps. Think again the second suggestion of Franco about a real target somewhere there before going for modifications.
No problem. I should have mentioned it from the beginning
Buried target tests have been performed, but in really "hard" soils, stones with nuggets can also be detected as targets.

[Jeg]

Thanks for sharing Rubin. I think it is difficult to avoid such cases no matter the frequency or the gain. If those soils are highly charged then receiver will be confused as all receivers i guess
which utilize electric field reception.

[JHERICKU]

Hi to all..To master Franci and friend Jeg..
My first attempt was not successfull so I decided to remake it based on the circuit I attached here.. can anyone review the circuit I made if there was mistakes on it..I made the power stage separated to sensor as master Franco stated..I don not have tupe C transistor so I used bc548b..
These were my observations:
1.1.853 volts without quartz on output..When I touched the antenna it increases to 3.911volts.
2.5.678volts with quartz on output and decreases when touched..
3.two leds were on,The first was steady and the second led qas blinking...Is this normal Franco?
4.The buzzer was annoying,it continuously beeping so loud and no way to lower it..
5.the voltage output was increasing when I touched the potentiometer knob..

What do you think Jeg?
ps.I used 4mhz quartz on 8mhz display one led..

[FrancoItaly]

If you read carefully the advice I gave for calibration, you see that without quartz the sensor stage DC output must be 0 V, otherwise self oscillation is present, and it is a condition to be avoided. The good news is that if there is self oscillation it means that the transistors have sufficient gain. Decrease C13 / C14, 330 pF or less, if not enough, increase R10 / R12, 1.2 K or 1.5 K.

[JHERICKU]

Thank you Franco..I will do ur advice..Is itnormal the leds are lighting?one was steady and the other one was blinking?I thought it only lights when there is a detection?

[Jeg]

Hey Jh
Also check in your diagram what i have in a red cycle. Are those points connected between each other as it should?
Check the green lines. It looks like your ground (-) connects to pins 2,3,4 while it needs to be attached only to 4.
I don't see something else. The rest of the circuit looks good.


After checking that you should follow what Franco wrote you above until you see zero volts at the output of sensor without crystal.

[FrancoItaly]

In the power stage the LED flashes when the supply voltage drops below 16V, and this is adjusted by means of the potentiometer P1. You can use a stabilized power supply instead of batteries and set it to 16V, then adjust P1 until the led starts flashing.

[JHERICKU]

Greeting to all especially to master franco..With potentiometers on max one led was on lights..when I placed my hand about 6 inches if turn off..when I toucehd the antenna..all leds will lights..
Any idea master?Thank u..

[FrancoItaly]

Greeting to all especially to master franco..With potentiometers on max one led was on lights..when I placed my hand about 6 inches if turn off..when I toucehd the antenna..all leds will lights..
Any idea master?Thank u..


As I have already said, the important thing is that by touching the antenna there is a change in signal, usually it is a decrease.

[ERDOGAN37]

https://www.youtube.com/watch?v=ZNoytV-mPKs

[Jeg]

https://www.youtube.com/watch?v=ZNoytV-mPKs


Great job Erdogan! ;)

[JHERICKU]

what version did you use my friend?did u able to eliminate the oscillation?

[ERDOGAN37]

My project is attached

[humhum]

Two coil for more small cap . :D

[humhum]

Best Low Bat Indicator .. 8)

[Jeg]

Two coil for more small cap . :D




niccce humhum!


I used the first technique recently (speaker wire) and its really very convenient. :)

[folharin]

I did all the franco circuits. Here in Brazil it doesn't work, not even in the test field...:n?o n?o::carranca:

[Jeg]

I did all the franco circuits. Here in Brazil it doesn't work, not even in the test field...:n?o n?o::carranca:

Hi folharin

How old is your test field?
What indication method did you pick up for your receiver?
Have you tested a voltmeter in place of leds?
Can you share how did you confirm that your device is built successfully?
Do you own an oscilloscope?

Thanks

[humhum]

I did all the franco circuits. Here in Brazil it doesn't work, not even in the test field...:n?o n?o::carranca:

For your country You can use FM Receive method and frequency of big master Esteban .

[tasmen]

Hi Mr Franco

I created version on 20Mhz (crystal 14Mhz). How can adjust to pot 1,2,3 and c10 to get the maximum performance to one harmonic?
I have not oscilloscope.
I can measure volts at the output?
The value i have to get?

Thank you in advance.

[FrancoItaly]

Hi Mr Franco

I created version on 20Mhz (crystal 14Mhz). How can adjust to pot 1,2,3 and c10 to get the maximum performance to one harmonic?
I have not oscilloscope.
I can measure volts at the output?
The value i have to get?

Thank you in advance.

Measurements must be made at the sensor stage output (direct voltage). C10 needs to be adjusted for maximum output. Obviously you have to follow the instructions of the helps, no signal must be there without the quartz and others.

[brain]

hello franco lrl, is it electrostatic or electromagnetic, can I get some information?

[FrancoItaly]

hello franco lrl, is it electrostatic or electromagnetic, can I get some information?

I think it's electromagnetic, I can't tell you more.

[ERDOGAN37]

https://youtube.com/shorts/4oYFSPlzWvc?feature=share
:)
Thanks Franco

[FrancoItaly]

https://youtube.com/shorts/4oYFSPlzWvc?feature=share
:)
Thanks Franco

Which version of my lrl did you make?

[ERDOGAN37]

LRL 2 project

[FrancoItaly]

LRL 2 project

20 Mhz ?

[ERDOGAN37]

yes 20 mhz

[mustefa ubram]

I finished the version 20mhz today.I have not tested in practice yet.But in practice it works like version 8mhz.With 22 pf capacitor, the output of the sensor is 5 volts dc.Touching the telescopic antenna reduces the output between 300 and 700 mV.I connect the sensor output to a 32-bit microcontroller.The measurement accuracy with the 32-bit microcontroller is very high and the smallest change is displayed.Currently I am facing a real test location challengePlease guide me in this regard

[FrancoItaly]

The 20 Mhz version is certainly more sensitive than the 8Mhz version because L1 / C10 is tuned on a 20 Mhz harmonic. To check correct operation, the rule is the same as the 8 Mhz version, that is, test on the test field.

[folharin]

I don't understand why this detector fails to manufacture it? honestly it doesn't work!

[folharin]

I have the proving ground and this detector really didn't work!!

[folharin]

newcomers to the group!search for alonso pd

[folharin]

two boxxxx

[Pahom]

I have the proving ground and this detector really didn't work!!
Try to pick up a capacitor parallel to the coil. And with the coil itself 3-4-5-6-7 turns. Or squeeze or stretch the turns of the coil to try on the track with the target.

[omar]

Hi Franco. What technology does the device use, is it BFO? The fact that there are two resonant circuits that have a harmonic frequency. When the device enters an electric or magnetic field, the resonance frequency changes by a difference of audible sound frequencies. With a low-pass filter with a cut-off frequency of 480Hz, a wide band. Is this the case?

[FrancoItaly]

Hi Franco. What technology does the device use, is it BFO? The fact that there are two resonant circuits that have a harmonic frequency. When the device enters an electric or magnetic field, the resonance frequency changes by a difference of audible sound frequencies. With a low-pass filter with a cut-off frequency of 480Hz, a wide band. Is this the case?

There is only one resonant circuit, L1 / C10, and it resonates in the FM range, the internal oscillator (quartz) provides a reference signal for the TR2 mixer, if L1 / C10 is tuned on a quartz harmonic the sensitivity is higher . You cannot compare the operation of this lrl to a metal detector, it is a passive receiver, but you could add an external oscillator (FM range). This is not a simple modification, without good shielding the external oscillator would saturate the sensor stage. I would also add that we do not know much about the phenomenon.

[Asheikh]

There is only one resonant circuit, L1 / C10, and it resonates in the FM range, the internal oscillator (quartz) provides a reference signal for the TR2 mixer, if L1 / C10 is tuned on a quartz harmonic the sensitivity is higher . You cannot compare the operation of this lrl to a metal detector, it is a passive receiver, but you could add an external oscillator (FM range). This is not a simple modification, without good shielding the external oscillator would saturate the sensor stage. I would also add that we do not know much about the phenomenon.
Hello
Before every thing, Thanks for your excellent circuit Mr Franco.
It seems your circuit isn't a passive device & it transmits harmonic signal to the Ant. through C2 & C9.
Gold & Silver are not radioactive metals & I think they haven't Phenomena from themselves.
I'm not a pro. engineer & perhaps in mistake.
Thanks

[FrancoItaly]

Hello
Before every thing, Thanks for your excellent circuit Mr Franco.
It seems your circuit isn't a passive device & it transmits harmonic signal to the Ant. through C2 & C9.
Gold & Silver are not radioactive metals & I think they haven't Phenomena from themselves.
I'm not a pro. engineer & perhaps in mistake.
Thanks

I confirm that my lrl is a passive receiver and in my opinion radioactivity is not the only phenomenon involved, I also confirm and many members have verified it, that my lrl is also sensitive to gold and silver. It is also true that in some places it does not work, here is the link of a video:

https://www.youtube.com/watch?v=yR3tzT2Jd-g&t=34s

[omar]

....... Thank you

[folharin]

group stopped?

[FrancoItaly]

group stopped?

I think there are major problems that people face right now, however I am there.

[folharin]

:D:cheers:

[detec]

My FrancoLRL-2

Thanks so much Franco


hi all, i need to know the coils specs at the bottom left near the antenna if i should solder 2 coils also the potentiometers and antenna and vumeter specs and thank you in advance.

[FrancoItaly]

hi all, i need to know the coils specs at the bottom left near the antenna if i should solder 2 coils also the potentiometers and antenna and vumeter specs and thank you in advance.

Sorry but I don't understand what you mean.

[detec]

thank you for your reply , i already made the walkman pcp and theres a version with 2 coils i put them both, i wanna ask if it will work, and the difference between 1 and 2 coils also the pot. and vu and gnd wiring as im a little familiar with pi and vlf but experementing with lrl and thank you again for your help.
ay extra tips or advice will be much appreciated
i used 184c

https://www.longrangelocators.com/forums/attachment.php?attachmentid=20441&stc=1&d=1572346353

[Pahom]

thank you for your reply , i already made the walkman pcp and theres a version with 2 coils i put them both, i wanna ask if it will work, and the difference between 1 and 2 coils also the pot. and vu and gnd wiring as im a little familiar with pi and vlf but experementing with lrl and thank you again for your help.
ay extra tips or advice will be much appreciated
i used 184c

https://www.longrangelocators.com/forums/attachment.php?attachmentid=20441&stc=1&d=1572346353

Concho will work if you correctly tune the input part and select the amplitude of the generator.

[detec]

thank you for your answer

[shahrayar]

Franco, is this based on radio transmitting stations?

[FrancoItaly]

Franco, is this based on radio transmitting stations?

I don't think so, even if near transmitters the lrl is saturated by the strong signal. The phenomenon is very complex and according to official science it does not exist. The fact remains that several forum members have told me that they have made many discoveries.

[shahrayar]

I don't think so, even if near transmitters the lrl is saturated by the strong signal. The phenomenon is very complex and according to official science it does not exist. The fact remains that several forum members have told me that they have made many discoveries.


Thank you, Franco, but the radio broadcasts have to stop until we're sure:lol::lol:
Really strange thing

[folharin]

I don't think so, even if near transmitters the lrl is saturated by the strong signal. The phenomenon is very complex and according to official science it does not exist. The fact remains that several forum members have told me that they have made many discoveries.
can you tell me which
member?..until today I haven't seen anyone in the group with good results with their lrl

[FrancoItaly]

can you tell me which
member?..until today I haven't seen anyone in the group with good results with their lrl

Most have contacted me via e-mail, however I invite whoever wants to confirm it on the forum, if they have no problems.

[Trojanali58]

Hello Mr. Franco I Wish You And Your Family Health And Well-Being. Thank You Very Much For Publishing This Circuit. The Circuit is Working Very Well And I Have Built Your 8 Mhz Circuit. I Discovered a Very Good Place With The Circuit.;)

[FrancoItaly]

Hello Mr. Franco I Wish You And Your Family Health And Well-Being. Thank You Very Much For Publishing This Circuit. The Circuit is Working Very Well And I Have Built Your 8 Mhz Circuit. I Discovered a Very Good Place With The Circuit.;)

I am glad that you have had good results, I repeat that the tuning must be accurate, just before the self oscillation starts, in this way you get a good sensitivity.

[Inna]

Hello to all this wonderful forum, I've just joined and I'm starting to make the project at 8MHz.
Meanwhile, a special thanks to Mr. Franco, a great person.
I would like to ask him or anyone who can kindly answer me: since this project has been modified by several people,
I can't figure out, for example, how many potentiometers there are to adjust outside the box, what values ​​they have and
where to connect them on the pcb. I specify that I made the Walkman pcb, the last one above, but I don't know if it's updated enough
to the various changes (for example there'nt the low battery control) but it is'nt a problem. Is there anyone who has an complete overall scheme or diagram

where it is possible to distinguish which are the potentiometers and which are the trimmers and how correct use in field search.
Thank you all.

[FrancoItaly]

Hello to all this wonderful forum, I've just joined and I'm starting to make the project at 8MHz.
Meanwhile, a special thanks to Mr. Franco, a great person.
I would like to ask him or anyone who can kindly answer me: since this project has been modified by several people,
I can't figure out, for example, how many potentiometers there are to adjust outside the box, what values ​​they have and
where to connect them on the pcb. I specify that I made the Walkman pcb, the last one above, but I don't know if it's updated enough
to the various changes (for example there'nt the low battery control) but it is'nt a problem. Is there anyone who has an complete overall scheme or diagram

where it is possible to distinguish which are the potentiometers and which are the trimmers and how correct use in field search.
Thank you all.

I post again the original lrl, modified with two pots for tuning and one for gain. The power supply stage with low battery is the one in the version with one LED, in the version with 3 LEDs it is not indicated but that of the 1 LED version must be used. The low battery regulation is a trimmer.

[Inna]

Dear Mr. Franco, I'm Italian and I would really liked to meet you in person because until a few years ago I lived in Genoa. But now unfortunately I find myself very far from Liguria. Besides, even my name is "Franco". I apologize again because I don't have a lot of experience in electronics, I'm a self-taught hobbyist. So if I choose to insert the new display stage, the external adjustment potentiometers would be: P1 of 47k. P2 of 1 Mega, P3 of 10k, it is right? Instead the power stage remains common for both versions and the antenna amplifier has a 4k7 trimmer. I would very much like to be able to write to you privately, but I'm not sure how to do it. Thank you for your great availability and kindness, as I have been able to see in this forum even with non-grateful people.

[FrancoItaly]

Dear Mr. Franco, I'm Italian and I would really liked to meet you in person because until a few years ago I lived in Genoa. But now unfortunately I find myself very far from Liguria. Besides, even my name is "Franco". I apologize again because I don't have a lot of experience in electronics, I'm a self-taught hobbyist. So if I choose to insert the new display stage, the external adjustment potentiometers would be: P1 of 47k. P2 of 1 Mega, P3 of 10k, it is right? Instead the power stage remains common for both versions and the antenna amplifier has a 4k7 trimmer. I would very much like to be able to write to you privately, but I'm not sure how to do it. Thank you for your great availability and kindness, as I have been able to see in this forum even with non-grateful people.


I sent you a private message, potentiometers are ok.

[Dubulumach]

Hello FrancoItaly and all

There is one optimal frequency 115.674 MHz and two variants of HC-49U quartz crystals.
1st. 115.5278 MHz main freq.
2nd. Overtone quartz 10.695 MHz or 10.700 MHz both are near geometric mean of main LC resonant tanl circuit.
L1 3 turns, wire diameter 1mm, 1.09mm enamelled, at 10 mm coil form, 10.5 mm lenght of coil with 3mm winding pitch.
Primary inductance 0.086 uH or 86 nH
Series resistance - 2.304 mOhm
Parallel resistance - 38.14 KOhm
Parallel capacitance Cs - 0.338 pico
Self resonant freq Fsr is very high 1.0895 GHz, wit Q-factor 619 and ESR 0.1 Ohm at 115.674 MHz
Together wit C10 ~ 22 pico, -3dB(Δf) bandwidth of parallel tank-circuit L1C10 is 302.5 KHz, Z= 63 Ohm and eq.resistance is Req = 21.93 KOhm.
Very probably LRL range is somewhere plus or minus 5Mhz from main oscillating LC tank-circuit freq. It should be from 110.5Mhz - 120.5 MHz. Phenomenon is very complex and no one living could explain it. It's all matter of experiments.

Regards :)

[FrancoItaly]

Hello FrancoItaly and all

There is one optimal frequency 115.674 MHz and two variants of HC-49U quartz crystals.
1st. 115.5278 MHz main freq.
2nd. Overtone quartz 10.695 MHz or 10.700 MHz both are near geometric mean of main LC resonant tanl circuit.
L1 3 turns, wire diameter 1mm, 1.09mm enamelled, at 10 mm coil form, 10.5 mm lenght of coil with 3mm winding pitch.
Primary inductance 0.086 uH or 86 nH
Series resistance - 2.304 mOhm
Parallel resistance - 38.14 KOhm
Parallel capacitance Cs - 0.338 pico
Self resonant freq Fsr is very high 1.0895 GHz, wit Q-factor 619 and ESR 0.1 Ohm at 115.674 MHz
Together wit C10 ~ 22 pico, -3dB(Δf) bandwidth of parallel tank-circuit L1C10 is 302.5 KHz, Z= 63 Ohm and eq.resistance is Req = 21.93 KOhm.
Very probably LRL range is somewhere plus or minus 5Mhz from main oscillating LC tank-circuit freq. It should be from 110.5Mhz - 120.5 MHz. Phenomenon is very complex and no one living could explain it. It's all matter of experiments.

Regards :)

Thanks for all these calculations, the 20 Mhz version operates by tuning L1/C10 on a higher harmonic of 20Mhz, thus increasing the efficiency of the mixer and therefore with a greater sensitivity of the sensor stage. The main problem is to avoid self oscillation.

[FrancoItaly]

My youtube channel

https://www.youtube.com/watch?v=BQ3aaN044MA

https://www.youtube.com/watch?v=wtgtj7G6L6U

https://www.youtube.com/watch?v=Sl4VtAmxCm0


https://www.youtube.com/watch?v=yR3tzT2Jd-g

[omar]

Hi Franco, why didn't you use a germanium diode? It has a wide range and ten times more sensitivity than a silicon diode 4148.

[FrancoItaly]

Hi Franco, why didn't you use a germanium diode? It has a wide range and ten times more sensitivity than a silicon diode 4148.

Germanium diodes are clearly inferior to silicon ones, the only advantage is to use them where a lower voltage drop is required. I don't understand what you mean by higher sensitivity, diodes don't amplify.

[Inna]

Hi, anyone could tell me what is the correct value to consider when the battery is low in this project (8 Mhz) ? Perhaps 11 Volt is right or other values?
Thanks at all.

[Pahom]

Hi, anyone could tell me what is the correct value to consider when the battery is low in this project (8 Mhz) ? Perhaps 11 Volt is right or other values?
Thanks at all.
No, below 12 volts, it will lag. Even more or less normal operation depends on the layout of the board.

[FrancoItaly]

No, below 12 volts, it will lag. Even more or less normal operation depends on the layout of the board.

My lrl runs at +12V stabilized, 2x 9V batteries in series give 18V, I consider them discharged when the voltage drops to +15.5V, as the stabilizer IC must have at its input a voltage at least +3V higher than the output.

[Inna]

Apologize again, but I have another question: instead of 1 Megaohm, can I use a 470 K for potentiometer P2? Due to logistical problems related to the place where I am, I can't find a higher value. Do you think it can be work better like with 1 Mohm? Is it perhaps better to also insert a fixed 100/220 ohm resistor in series with p2?
Thanks again.

[FrancoItaly]

Apologize again, but I have another question: instead of 1 Megaohm, can I use a 470 K for potentiometer P2? Due to logistical problems related to the place where I am, I can't find a higher value. Do you think it can be work better like with 1 Mohm? Is it perhaps better to also insert a fixed 100/220 ohm resistor in series with p2?
Thanks again.

You can put 470K in series with potentiometer, that way you can adjust the gain from half to full. Or you can use a 1M trimmer and adjust it for the greatest gain without having instability. Rarely do you adjust the gain, once you find the right value, also the gain can be decreased by lowering the threshold.

[Inna]

Yes, I wrote wrong, I meant 100/220 kohm. You have to excuse me, but I'm just an electronics hobbyist, so P2 adjusts the gain which, once adjusted, always remains the same, so it's possible not to take it out of the box and replace it with an internal trimmer. Then If I may ask again, what do the other 2 potentiometers regulate? To be clearer, Mr. Franco, I ask you, could you describe what to do with the device and how to adjust it for research, after turning it on? That is, on which potentiometers to intervene and how to start field research? In short, having a small user manual on plein-air...
Thanks for your patience.

[FrancoItaly]

Yes, I wrote wrong, I meant 100/220 kohm. You have to excuse me, but I'm just an electronics hobbyist, so P2 adjusts the gain which, once adjusted, always remains the same, so it's possible not to take it out of the box and replace it with an internal trimmer. Then If I may ask again, what do the other 2 potentiometers regulate? To be clearer, Mr. Franco, I ask you, could you describe what to do with the device and how to adjust it for research, after turning it on? That is, on which potentiometers to intervene and how to start field research? In short, having a small user manual on plein-air...
Thanks for your patience.

In the original version there was only one potentiometer for threshold adjustment, later I added another one, so one is for fine tuning and the other for coarse tuning. You operate in the same way as a metal detector, adjust the gain, if any, for a stable threshold and then adjust the threshold, just below the point where the first LED lights up.

[omar]

Found this diagram on a site and it looks nice


https://j.top4top.io/p_2529kc9st0.jpg (https://top4top.io/)

[Inna]

Found this diagram on a site and it looks nice


https://j.top4top.io/p_2529kc9st0.jpg (https://top4top.io/)

Very good, the antenna amplifier and the battery monitor are missing, but that's not a problem. Could you kindly share the site from which to download the files, also to have the right sizes of the pcb.
Thank you.

[FrancoItaly]

Very good, the antenna amplifier and the battery monitor are missing, but that's not a problem. Could you kindly share the site from which to download the files, also to have the right sizes of the pcb.
Thank you.

Thank you, it will be very useful for many forum members.

[Inna]

Does the last pcb version also include a variable condensator on the antenna input? This could be a good chance?

[omar]

https://top4top.io/downloadf-2530spk8i0-rar.html

[FrancoItaly]

Does the last pcb version also include a variable condensator on the antenna input? This could be a good chance?

A variable condenser on the antenna input can be useful in the 20Mhz version where a 20Mhz crystal is used and the antenna circuit is tuned on a harmonic of the oscillator, it can be 80 or 100Mhz. With 8Mhz quartz the harmonics have too small amplitude. However, with the 8 Mhz version, you can try to adjust the capacitor to look for a point where the DC output signal increases, possibly putting a 22pF capacitor in parallel with the variable capacitor.

[Inna]

A variable condenser on the antenna input can be useful in the 20Mhz version where a 20Mhz crystal is used and the antenna circuit is tuned on a harmonic of the oscillator, it can be 80 or 100Mhz. With 8Mhz quartz the harmonics have too small amplitude. However, with the 8 Mhz version, you can try to adjust the capacitor to look for a point where the DC output signal increases, possibly putting a 22pF capacitor in parallel with the variable capacitor.

A variable capacitor like these?

[FrancoItaly]

A variable capacitor like these?

Yes, 50pF is ok.

[Inna]

Yes, 50pF is ok.

Thanks! Always there to help. Great Mr. Franco.

[Inna]

Sorry again, but on this pcb posted by Omar, I can't find the solder point for the antenna. Capacitor values ​​are not written. With a little patience they can be deduced, even if at sight, they seem much more than those in the original scheme. Instead in the point that I highlighted with an orange circle, I can't figure out what should be connected to it.

[omar]

Dear, the point you marked with a circle. It is the measuring point of the sensor output.

I will use my friend to write down the missing values

[Inna]

Dear, the point you marked with a circle. It is the measuring point of the sensor output.

I will use my friend to write down the missing values

Thanks Omar, please could you ask even where is the antenna point?

[omar]

https://h.top4top.io/p_2532q83vs0.jpg (https://top4top.io/)

[Inna]

https://h.top4top.io/p_2532q83vs0.jpg (https://top4top.io/)

Great! Well done Omar!

[rxlock2]

can someone put the PCB in PDF for printing

[FrancoItaly]

can someone put the PCB in PDF for printing


Of course you have to reduce the size.

[rxlock2]

Of course you have to reduce the size.Thanks a lot, but I mean the PCB in PDF format to make it a board

[Pahom]

Thanks a lot, but I mean the PCB in PDF format to make it a board
This board is in Laot, the link is in the posts above. If you can not download the link, I can send you a personal mail.

[rxlock2]

This board is in Laot, the link is in the posts above. If you can not download the link, I can send you a personal mail.
I don't want a file in lay format, but in PDF format like in the photo so I can print it
mail: rxlock2@gmail.com
Τhanks.

[Pahom]

I don't want a file in lay format, but in PDF format like in the photo so I can print it
mail: rxlock2@gmail.com
Τhanks.Laot is a simple program, very easy to master. And you can also print the layout on a printer. All tutorial videos are on YouTube. Nothing complicated. And look at your mail.

[rxlock2]

Laot is a simple program, very easy to master. And you can also print the layout on a printer. All tutorial videos are on YouTube. Nothing complicated. And look at your mail.

Thank you very much

[omar]

can someone put the PCB in PDF for printing


https://top4top.io/downloadf-2551qpyt80-rar.html

[rxlock2]

https://top4top.io/downloadf-2551qpyt80-rar.html
Thank you

[abdou2014]

are there layout pcb ?

[Pahom]

are there layout pcb ?

Oh how, you missed a lot, everything is in the posts above ... and the boards and the circuit have not changed.

[abdou2014]

THERE IS ONLY PDF FILE

[omar]

I think that Franco's device needs a second independent device that transmits radio frequencies AM / SW modulated regular sound waves from 500 Hz to 2.5 kHz. to stimulate the phenomenon.

https://i.top4top.io/p_2556imfqz0.png (https://top4top.io/)

https://e.top4top.io/p_2556jvp490.png (https://top4top.io/)

[omar]

When a sample is placed in a constant magnetic field and stimulated (perturbed) by a time-varying (e.g., pulsed or alternating) magnetic field, NMR active nuclei resonate at characteristic frequencies. Examples of such NMR active nuclei are the isotopes carbon-13 and hydrogen-1 (which in NMR is conventionally known as proton NMR). The resonant frequency of each isotope is directly proportional to the strength of the applied magnetic field, and the magnetogyric or gyromagnetic ratio of that isotope. The signal strength is proportional both to the stimulating magnetic field and the number of nuclei of that isotope in the sample. Thus in the 21 tesla magnetic field that may be found in high resolution laboratory NMR spectrometers, protons resonate at 900 MHz. However, in the Earth's magnetic field the same nuclei resonate at audio frequencies of around (2 kHz) and generate very weak signals

https://k.top4top.io/m_2556md8ot0.bmp

[FrancoItaly]

I think that Franco's device needs a second independent device that transmits radio frequencies AM / SW modulated regular sound waves from 500 Hz to 2.5 kHz. to stimulate the phenomenon.

https://i.top4top.io/p_2556imfqz0.png (https://top4top.io/)

https://e.top4top.io/p_2556jvp490.png (https://top4top.io/)

It is possible, but the L/C resonant circuit is in the FM range and therefore the frequency of the external oscillator must be tuned to this frequency (or one of its harmonics).

[omar]

My idea, my friend Franco, is as shown in the pictures below. An MP3 player can be used in the car as a transmitter by adjusting the capacity, although its energy is low, but it is ready and cheap. And good luck.



https://mrkzgulfup.com/uploads/167251048730521.png (https://mrkzgulfup.com/)

[FrancoItaly]

My idea, my friend Franco, is as shown in the pictures below. An MP3 player can be used in the car as a transmitter by adjusting the capacity, although its energy is low, but it is ready and cheap. And good luck.



https://mrkzgulfup.com/uploads/167251048730521.png (https://mrkzgulfup.com/)

I sincerely think that a dedicated, more versatile system would be better, also because it should be used together with the lrl, i.e. permanently connected to it.

[Pahom]

[QUOTE=FrancoItaly;161971]It is possible, but the L/C resonant circuit is in the FM range and therefore the frequency of the external oscillator must be tuned to this frequency (or one of its harmonics).
Omar on this board has one small mistake c16 33n must be based on Tr5

[rxlock2]

[QUOTE=FrancoItaly;161971]It is possible, but the L/C resonant circuit is in the FM range and therefore the frequency of the external oscillator must be tuned to this frequency (or one of its harmonics).
Omar on this board has one small mistake c16 33n must be based on Tr5

Pahom is right.
As Omar has installed C16, the circuit does not work.

[omar]

thank you my friends. the mistake has been fixed. And good luck

https://top4top.io/downloadf-2557vef7b0-rar.html



https://j.top4top.io/p_2557d9e190.jpg (https://top4top.io/)

[Inna]

Thanks Omar, due to my personally needs of container size and how I engineered my device, I had to rearrange and redesign the pcb's tracks. I had checked them one by one, but I hadn't noticed the error on c16. So that's the only mistake made, is everything else ok?

[omar]

Thanks Omar, due to my personally needs of container size and how I engineered my device, I had to rearrange and redesign the pcb's tracks. I had checked them one by one, but I hadn't noticed the error on c16. So that's the only mistake made, is everything else ok?


My apologies to you, my friend, and to the others. Unfortunately, I did not check the drawing because the circuit is simple, but now I checked the drawing. There are no errors, it is only the location of the 33nF capacitor, and it has been corrected. And good luck

[Pahom]

[QUOTE=omar;161992]My apologies to you, my friend, and to the others. Unfortunately, I did not check the drawing because the circuit is simple, but now I checked the drawing. There are no errors, it is only the location of the 33nF capacitor, and it has been corrected. And good luck[/QUOTOmar, everything is fine. For this, forums are created. To communicate, share, help whenever possible. The board is working, only as Franco recommended, it should be done on two-sided fiberglass. Then there is less fluctuation at the control point.

[omar]

The pieces must be soldered immediately after cleaning the board, because the copper oxidizes quickly and the problem arises. And it must be ensured that the pieces are welded correctly, because weak welding means a weak connection or separation, and this fails the device to work. Transistors whose gain is not less than 450hfe should be used, such as BC183C, bc184c, or bc173c. For example, (BC547C is not suitable, as it will not achieve the required gains, and therefore the device has little sensitivity.) To increase the gain and extend the FM range you can use 2N7052 OR 2N7053. The device suffers from the need for frequent rebalancing like other conventional metal detectors.( What is not known is whether the full FM signal reaches the detection diode)

[Pahom]

The pieces must be soldered immediately after cleaning the board, because the copper oxidizes quickly and the problem arises. And it must be ensured that the pieces are welded correctly, because weak welding means a weak connection or separation, and this fails the device to work. Transistors whose gain is not less than 450hfe should be used, such as BC183C, bc184c, or bc173c. For example, (BC547C is not suitable, as it will not achieve the required gains, and therefore the device has little sensitivity.) To increase the gain and extend the FM range you can use 2N7052 OR 2N7053. The device suffers from the need for frequent rebalancing like other conventional metal detectors.( What is not known is whether the full FM signal reaches the detection diode)

Thanks Omar! Cool transistors need to buy these !!!!

[FrancoItaly]

Some considerations:

if the sensor stage auto oscillates it means that the amplification is sufficient, provided that the oscillation does not occur due to an unsuitable pcb.

If transistors with sufficient gain are not found, R10 and R12 can be decreased, for example 470 ohms.

The voltage drop of the diodes does not matter since the voltage changes are measured.

The FM signal is processed in mixer stage TR2 and is not amplified further.

[Ertron30]

thank you my friends. the mistake has been fixed. And good luck

https://top4top.io/downloadf-2557vef7b0-rar.html



https://j.top4top.io/p_2557d9e190.jpg (https://top4top.io/)

This file cannot be downloaded. do you have the lay6 file

[Inna]

My apologies to you, my friend, and to the others. Unfortunately, I did not check the drawing because the circuit is simple, but now I checked the drawing. There are no errors, it is only the location of the 33nF capacitor, and it has been corrected. And good luck

No problem Omar, indeed I personally thank you for posting your pcb, it served me a lot as a starting point for developing my circuit. The important thing is to collaborate, notice mistakes and correct them. We are human... I wanted to ask the more experienced ones, is the BC548C ok?

[omar]

The bc547c / bc548c / bc549c transistors have a gain in the lower limits of 420hfe.
The circuit needs to adjust and reduce the value of the resistance R12 to achieve the required gain with it. As our friend Franco said.

Note it has a wider bandwidth than the bc183c

[omar]

[]This file cannot be downloaded. do you have the lay6 file.

The download link is working.

[Inna]

The bc547c / bc548c / bc549c transistors have a gain in the lower limits of 420hfe.
The circuit needs to adjust and reduce the value of the resistance R12 to achieve the required gain with it. As our friend Franco said.

Note it has a wider bandwidth than the bc183c

I'm sorry Omar, but the 548C has hfe gain from 420 to 800, the ones I selected for my circuit, I tested them with a Chinese multi-tester and they all have hfe values ​​above 500. Do you think it's too low? Better if I replace them or by intervening on the resistors, can I still get a good result?

[FrancoItaly]

I'm sorry Omar, but the 548C has hfe gain from 420 to 800, the ones I selected for my circuit, I tested them with a Chinese multi-tester and they all have hfe values ​​above 500. Do you think it's too low? Better if I replace them or by intervening on the resistors, can I still get a good result?

A gain of 500 is sufficient, by the way higher values are difficult to obtain.

[Inna]

A gain of 500 is sufficient, by the way higher values are difficult to obtain.

Thanks mr. Franco, so if I change the values ​​of r10 and r11 to 470 ohms, I can use the bc548cs, increasing the gain a bit.... Is that right?

[Inna]

Sorry, errata corrige: r10 and r 12...

[omar]

Thanks mr. Franco, so if I change the values ​​of r10 and r11 to 470 ohms, I can use the bc548cs, increasing the gain a bit.... Is that right?




Back up. Put in variable resistors to increase the gain when you need it. So as not to disassemble and install and damage the circuit. I know that the device must sense the magnetic north and the sky, then it is ready for field work.

https://b.top4top.io/p_2561jipik0.jpg (https://top4top.io/)

[omar]

note. Variable rectifiers are set only once. When the desired sensitivity is reached. Leave the third leg of the variable resistance in the air means not connected.

In the end, I extend my thanks and gratitude to our friend Franco for supporting the topic and helping the members.


https://top4top.io/downloadf-2561g1si50-rar.html

[Inna]

Well done. When you get the right gain value, if possible, you can replace the trimmers with fixed resistors with a value close to the value measured between the extreme pin and the central pin which are connected to the pcb.

[FrancoItaly]

Thanks mr. Franco, so if I change the values ​​of r10 and r11 to 470 ohms, I can use the bc548cs, increasing the gain a bit.... Is that right?

Yes

[abdou2014]

I made a modification of franco lrl this week, and I have very strange results ???
no reaction to electrical or magnetic interference, it only reacts to the white LED lamp, and the sound is very looklike to a magnetometer ??

[Inna]

Please, can anyone tell me if this coil (L1) is correct? Is the number of turns right as seen in the picture? I add that the diameter is 1 cm, while the section of the wire is 0.7 mm. Do I necessarily have to use the 1 mm wire? Thank you.

[FrancoItaly]

The coil is perfect, however it is not critical.

[Inna]

Good morning to everyone. Sorry if I ask questions that may have already been answered in the past. But I saw on a YouTube video that someone put a digital display voltmeter on this device. I wanted to know what its function could be and the difference, from the 3-leds monitor, and if it a good thing to mount on. And possibly where it should be connected. Maybe the (-) on ground and the (+) on TR5's emitter output? Thank you.

[Inna]

To be clear: in this point?

[FrancoItaly]

In my opinion 3 leds are sufficient, however a digital display voltmeter must be connected to the output of the first LM358 which is the DC amplifier stage.

[Inna]

In my opinion 3 leds are sufficient, however a digital display voltmeter must be connected to the output of the first LM358 which is the DC amplifier stage.

Good morning Mr. Franco, please could you tell me the right point to connect the display on first LM358?
Many thanks.

[FrancoItaly]

Digital meter at IC1A output and ground. However, the stage relating to the buzzer and the first LED is necessary. I attach a display stage easier to adjust the threshold.

[Inna]

Because I made the last Omar's pcb, I should ask if It's the blue point in the attached scheme, the right point to connect the (+) positive input of the multimeter?

[FrancoItaly]

Yes it's correct.

[Inna]

Hello, I would like to ask if it was possible to power this device with a single 9V battery and then a 12V regulated step-up module, thus eliminating the 7812. Has anyone already tried it? Could it work like this? Thanks.

[FrancoItaly]

I do not recommend this solution, as these step-up modules work via an internal oscillator which could interfere with the sensor stage.

[Inna]

Good advice. Thanks Mr. Franco.

[Inna]

Hi Mr. Franco,
I'm talking to you because lately this forum seems to be little frequented. Too bad because it's so interesting, but I also understand that I'm the last to arrive and I missed the best...
I still have to finish building your LRL and for an inexperienced one like me, I already foresee many problems in the calibration.
However I'm always wondering if it was possible to improve the aspect concerning the power supply of the device and I asked and proposed if, in order not to affect the circuit, to be able to use a 12V, 1.2Ah lead battery + the step-up module or possibly a diode booster circuit, to raise the voltage to 16/18 Volt.
But this time, these elements will have to be released from the body of the LRL, ie distant and connected for example to the handle, through a simple cable.
Maybe it could improve stability and battery work time. Sorry if I ask many questions.
Thanks for your help, always in time.

[FrancoItaly]

Yes, it's true, at the moment the forum is not very popular, but there are few topics to develop, however lrl from Italy has reached almost one million views, even in many years of activity. The lrl is not simple to implement, where there is a large amplification at relatively high frequencies there are always problems. The only pcb I made and made available is the sensor stage , and I recommended to use a double sided pcb, or shield the bottom with aluminum foil or another unetched pcb. The first lrl had no oscillator but simply self-oscillated, it was a bug detector that I found worked like the lrl. About power I recommend you again to use the original system with two 9V batteries, over all the consumption is about 20mA.

[Inna]

Yes, Mr. Franco, I will leave the power supply as the original. I'm doing a very particular montage, I used a plastic container that covered a bottle of perfume. I will connect the handle to the negative on the outside, to have contact with the hands and I will put the batteries in the hollow handle. As for the pcb, I chose to process the last one posted by Omar and I've already shielded it with a sandwich made up of a layer of aluminum foil below and a layer of cardboard above, so it will be well insulated from contact with the pcb tracks. But the aluminum is also connected to the negative like the handle. I also built the antenna amplifier that was suggested separately, I provided the 40 pF variable capacitor (the only one value now I have) at the antenna input, so as I wrote, it won't be easy to calibrate everything, there are many variables. I'm afraid I have to ask for his help often. However for now I'm going ahead with the construction, when I can due to lack of time. Thank you.

[omar]

A person photographed and detected (iron grille) inside a concrete wall in infrared. It seems that metals, especially those with heavy atoms, are radioactive when they are under pressure.
https://j.top4top.io/p_257371s020.jpg (https://top4top.io/)

If you photograph a large amount of gold, such as a goldsmith's shop, with a mobile camera, with the flash on. You will clearly see that gold sends low-frequency electromagnetic pulses in the form of circular packages. It is detected by photoinduction. The phenomenon, and God knows best, exists. But where is the right way? We do not know . Thanks

[Inna]

Hi Omar, about the picture above: it's an infrared or an ultraviolet photograph?

[aft_72005]

thank you my friends. the mistake has been fixed. And good luck

https://top4top.io/downloadf-2557vef7b0-rar.html



https://j.top4top.io/p_2557d9e190.jpg (https://top4top.io/)







.......link not downloadable

[Inna]

Strange... I can download it.

[Inna]

Sorry, I want to post the .rar file directly, but the system doesn't accept it and doesn't allow it to load, because the file is over 1 mb.

[Inna]

I want to help you, click at the link and after on the points shown in the attached images.

[aft_72005]

I want to help you, click at the link and after on the points shown in the attached images.




i did as you said ...but it not downloaded.anyway thanks for your guide .

[Inna]

Hi to everyone...

[Inna]

Hello, if anyone is interested, this is my version of the "Franco LRL" still under construction. I am Italian, like Mr. Franco and I am a designer. It may seem strange, but I always try to create and possibly reuse objects that were previously intended for another use. I study the feasibility and then adapt everything. In this case I used the plastic cover of a bottle of Italian men's perfume. The handle, which will contain the 2 batteries, is instead a bottle of shampoo. Don't pay attention to the graphics because they are my decorative writings.

[FrancoItaly]

In my laboratory I keep all the plastic containers that I might need in the future. However, what matters is the substance, not the appearance.

[Inna]

In my laboratory I keep all the plastic containers that I might need in the future. However, what matters is the substance, not the appearance.


Of course Mr. Franco, you must forgive me because the creative and aesthetic side is in my nature and I always try to put a little of it into everything I do. I try to recycle when I can. However it's right that, especially in an electronic assembly, the essential thing is the correct functioning and for this I will surely need your help since I'm not an expert at all and who better than you can give advice, since the lrl is your project? For now I'm going ahead with the assembly, later, maybe I'll ask you to guide me in the calibration. Thank you

[sweker]

hello for all , my name is sweker ,and I am interested in lrl that made by franco , I have already constructed it it work for near distance , actually I am facing problems with antenna setup, will left some picture that may help , I need your opinion Mr franco[/FONT]

[FrancoItaly]

Since my lrl is a passive receiver there is almost certainly not enough amplification in the sensor stage. In fact, I recommend adjusting the amplification just below the self-oscillation threshold and for this you need transistors with gain >500. The pcb is important, it must be double-sided or with shielding on the lower part, this is to prevent self-oscillation before having sufficient gain. If this is not enough you can increase the gain in the display stage.

[sweker]

2094020940

20941thank you ,your opinion please

[FrancoItaly]

I'm sorry but I'm not able to give an opinion, however it has a professional look; I used a pcb only for the sensor stage to minimize the possibility of self-oscillations and I can't tell if a single pcb for the whole lrl is valid. The only possibility is to use a pcb tested by others and certainly working.

[sweker]

thank you Mr franco for your advice , I want any one who build the device and test it to show with vedio the practice in the outer field

[Inna]

2094020940

20941thank you ,your opinion please

Please can you tell me what kind of transistors you used, because the writing on the schematic is illegible. Thanks.

[Inna]

Hi Omar, I realize only now that in your pcb C6 and C8 (electrolytic capacitors) are marked with a value of 10 uF, while on the diagram, Mr. Franco puts them at 100 uF, I wanted to confirm if this is a writing error. Thank you

[Inna]

Plesae, I know it may seem like a trivial question, but can someone tell me where the out voltage should be measured, which must be around 5 Volts, point n. 1 or 2?.
I would not have made a mistake so far to measure it on the TR5 emitter.

[Inna]

Unfortunately this forum has lost interest, a pity because there will always be someone who will arrive late... I always measured at point 1, but if instead the voltage is to be measured at point 2, I must surely change something, such as the network of capacitors from 1pF.

[sweker]

Since my lrl is a passive receiver there is almost certainly not enough amplification in the sensor stage. In fact, I recommend adjusting the amplification just below the self-oscillation threshold and for this you need transistors with gain >500. The pcb is important, it must be double-sided or with shielding on the lower part, this is to prevent self-oscillation before having sufficient gain. If this is not enough you can increase the gain in the display stage.

hello Mr franco I hope you are doing well, can you add frequency counter scheme to sensor stage

[FrancoItaly]

In my opinion it is not possible in fact even by connecting an oscilloscope the signal is interrupted.

[omar]

[QUOTE=Inna;162126]Hi Omar, I realize only now that in your pcb C6 and C8 (electrolytic capacitors) are marked with a value of 10 uF, while on the diagram, Mr. Franco puts them at 100 uF, I wanted to confirm if this is a writing error. Thank you


Hi my friend these capacitors are to smooth the current. Put what you see fit. I ask you to view this blog to understand more about some things, as it is similar to the Franco device.


http://techlib.com/electronics/allband.htm

[FrancoItaly]

The circuit is interesting, but I have some doubts about the values of 10M and 100k, they seem too high for bipolar transistors.

[sweker]

20949 this is the last design for franco lrl

[FrancoItaly]

The antenna seems too short, I recommend in the 30-40cm range, increasing the length of the antenna increases the sensitivity and vice versa.

[sweker]

MR FRANCO CAN YOU please put full pdf descriptions of 20 mhz version

[FrancoItaly]

Remember that I have created 3 20Mh lrls and only the first one works well, therefore I cannot provide assistance because I did not understand what the problem was with the 2 non-functioning lrls. However it is important to make a pcb only for the sensor stage.

[sweker]

Remember that I have created 3 20Mh lrls and only the first one works well, therefore I cannot provide assistance because I did not understand what the problem was with the 2 non-functioning lrls. However it is important to make a pcb only for the sensor stage.

MR Franco I have three questions thankfully
1. can I use stable power supply 12v instead your18 v power stage?
2. does the display stage work probably with stable power supply 12v ?
3. what Is the value of P 2 in the new display stage ..is it 1 M ?
thank you so much

[FrancoItaly]

All my lrl runs on stabilized 12V and since the stabilizer IC requires at least 15V (12V + 3V) to work properly I used two 9V batteries. Any other system that supplies stabilized 12V is fine.
Potentiometer P2 is 1M.

[sweker]

All my lrl runs on stabilized 12V and since the stabilizer IC requires at least 15V (12V + 3V) to work properly I used two 9V batteries. Any other system that supplies stabilized 12V is fine.
Potentiometer P2 is 1M.

Hello again MR FRANCO ,Did you use two separate pcb for sensor stage of 20 Mz as you mention in the help paper (the 20Mz oscillator has 2 transistors and various additional components, therefore it will have to be made on a separate pcb )

[FrancoItaly]

There isn't an extra transistor, if you only have one pcb for everything you can try it like this, it might even work, I have no experience on this, I always used two pcb.

[sweker]

20957There isn't an extra transistor, if you only have one pcb for everything you can try it like this, it might even work, I have no experience on this, I always used two pcb.

20956
MR Franco Honestly I did not understand the steps of adjusting the device to prevent self oscillation , could you please write it in steps or give me voice instruction step by step

[FrancoItaly]

I'm sorry, but I warned on the forum that I couldn't help to build the 20Mhz lrl, because only the first lrl works, but the following two don't, probably the project is too critical. Also my English is written only.

[sweker]

I'm sorry, but I warned on the forum that I couldn't help to build the 20Mhz lrl, because only the first lrl works, but the following two don't, probably the project is too critical. Also my English is written only.
MR FRANCO at the testing stage as you said do not connect the quartz then test the voltage at the out , which out do you mean to be measured?20958

[FrancoItaly]

I briefly summarize the operation, the sensor stage amplifies the oscillator signal which must be very small otherwise the sensor stage is saturated, in the mixer TR2 the mixing of the oscillator signal and the "phenomenon" takes place. Removing the crystal, therefore without oscillation, the output must be 0, if there is a DC signal it means that the whole sensor stage auto oscillates, an undesirable condition because putting the crystal would have a low sensitivity. Then decrease the amplification until the output is zero, this can be done by decreasing C13/C/14.

[sweker]

I briefly summarize the operation, the sensor stage amplifies the oscillator signal which must be very small otherwise the sensor stage is saturated, in the mixer TR2 the mixing of the oscillator signal and the "phenomenon" takes place. Removing the crystal, therefore without oscillation, the output must be 0, if there is a DC signal it means that the whole sensor stage auto oscillates, an undesirable condition because putting the crystal would have a low sensitivity. Then decrease the amplification until the output is zero, this can be done by decreasing C13/C/14.

MR Franco can I add antenna amplifier on the same pcb sensor stage ?

[FrancoItaly]

Yes.

[FrancoItaly]

Although in several years this thread has surpassed 1,000,000 views, a huge number considering this is a very specialized topic. I want to thank everyone who actively participated in this thread and also privately. I think my lrl was the only one for which all the data and assistance to build it were given, I was told that in some countries the kit is sold and I don't mind it, on the contrary it is further proof of the goodness of the project, furthermore not everyone is able to make the PCBs and the calibrations.

[sweker]

Although in several years this thread has surpassed 1,000,000 views, a huge number considering this is a very specialized topic. I want to thank everyone who actively participated in this thread and also privately. I think my lrl was the only one for which all the data and assistance to build it were given, I was told that in some countries the kit is sold and I don't mind it, on the contrary it is further proof of the goodness of the project, furthermore not everyone is able to make the PCBs and the calibrations.

I also thank God very much, and then thank you because you were so generous and did not skimp on us with any information and did not spare any effort to help us , thank you Mr franco

[FrancoItaly]

Thank you for your compliments.

[Pahom]

Yes.
Adjust according to Franco's recommendation. Be sure to top layer copper to avoid vibrations.

[sweker]

Adjust according to Franco's recommendation. Be sure to top layer copper to avoid vibrations.

thank you so much bro , but it does not open with spring layout 6

[Pahom]

thank you so much bro , but it does not open with spring layout 6

You are the first who complained. I downloaded it myself and everything opens. Do you have the sixth version of the program?

[sweker]

20962You are the first who complained. I downloaded it myself and everything opens. Do you have the sixth version of the program?

[Pahom]

20962Demo version, this is a limited version, which is probably why it does not open the file. Install the normal version.

[folharin]

this device does not work.I tested all versions..but here in Brazil, it's useless!!!

[sweker]

this device does not work.I tested all versions..but here in Brazil, it's useless!!!

in which way do you mean by it does not work,it does not work at all or it does not catch the phenomena?

[folharin]

in which way do you mean by it does not work,it does not work at all or it does not catch the phenomena?it works in other countries.. here in Brazil it doesn't get results! but I heard opinions that in several countries it proved to be efficient

[Babak Ruby]

Many thanks to the hardworking managers and Franco. Is the effect of the earth's field on metals in the plains and mountains the same, and does this system react in the same way for these areas?

[FrancoItaly]

Many thanks to the hardworking managers and Franco. Is the effect of the earth's field on metals in the plains and mountains the same, and does this system react in the same way for these areas?

Unfortunately I cannot give an answer, having little experience on different types of terrain, but since the phenomenon certainly also depends on the earth's magnetic field, I believe that there is little difference between mountains and plains. Instead, near the equator, where the north and south poles are at the same distance there could be an attenuation or perhaps disappearance of the phenomenon.