Lrl from Italy

[FrancoItaly]

HI Bill512,
If you are sure that in the presence of metals buried by the time the LED goes out, then you have to connect R5 to pin not inverting of LM358 and the cursor of P3 to R6 (inverting pin). While the phenomenon always causes an increase of the signal is possible that the phase change is acting contrary to your Llrl or in your country. In my LRL output of the CD4046 (pin 2) there is a negative change that is reversed by the LM358 because it is necessary that the signal increases to turn on the LED.
regards

[mustefa ubram]

hi franco
I'd attach a uv meter with microcontroller for 8mhz circuit .I want to know what part of input uv meter should be connected of 8mhz circuit?
Is located in the center of the phenomenon changes the overall frequency of the oscillator?

[Bill512]

Hey Bill artist....

thanks Geo.
Probably, this LRL it will be a nice experimental instrument.

[Bill512]

HI Bill512,
If you are sure that in the presence of metals buried by the time the LED goes out, then you have to connect R5 to pin not inverting of LM358 and the cursor of P3 to R6 (inverting pin). While the phenomenon always causes an increase of the signal is possible that the phase change is acting contrary to your Llrl or in your country. In my LRL output of the CD4046 (pin 2) there is a negative change that is reversed by the LM358 because it is necessary that the signal increases to turn on the LED.
regards

thanks for the reply Franco.
For the moment, I will leave it "as is".
The point is to find buried metals and explore further the associated phenomena.
So, the inverted output is not a big issue.

[Geo]

Bill, did you test it at Leon's field test???
It must locate the buried gold coin

Regards

[FrancoItaly]

Hi Mustefa,
You can connect the Vmeter at the out of IC1A.
Regards

[mustefa ubram]

franco in your lrl with 8mhz frq and cap 22p The inductance L1 is about 180 Nanohenries ?true?
http://chemelec.com/Calculators/LC-Calculator.htm

franco i think this is mistak.with cap 22p and 180nh resonance is for L1 79mhz.for 8mhz we need 18microhenri self.with this resonance we need 18turn of 1mm wire with 1cm diameter.
What is opinion?

[Bill512]

Bill, did you test it at Leon's field test???
It must locate the buried gold coin

Regards

not yet George, but I think that it would be a difficult task - this gold coin is buried deep (+90cm).

[reza vir]

If you use coins from 1 to 10 cm
If the number of coins you in more depth
Depending on the size and durability of metal in the soil Zaid

[Geo]

not yet George, but I think that it would be a difficult task - this gold coin is buried deep (+90cm).

Yes it is deep but we catch the phenomenon with the other lrl....

[Geo]

Hi HOBBIT
Tune P1 for about 3Mhz, tune P2 for about 1-6V (AC signal) at point X and at pin2 (phase comparator output) a DC signal 0.5-6V. This is not a metal detector and hand tests serve little. As I said and I repeat here there is no other way to test the lrls, you must have a long buried metal that is in same place at least a few months (for my experience) or to know a place where there is surely a long buried metal. An empirical system is exploiting the compass effect, you need to adjust the gain towards the maximum sensitivity until you have the compass effect then you have to lower the gain until it disappears. This happens with my lrl.
Best Regards

Hi Franco.
Yesterday i tried to adjust the lrl properly.
It was unable to make it oscillate at 3 Mhz so i replace the capacitor from 68p to 47 pf.
Now output at pin 3,4 is square signal 3 mhz. Signal at point X is triangular 6V but at pin2 is not DC but a not clear triangular. Is it right???

Regards

[reza vir]

Hey why do not you instead of 8 MHz to 3 MHz frequency do you use?
Do you have any particular reason?
Most devices operate below 1 MHz?

[Nicolas]

Right is 3Mhz

Hi Franco.
Yesterday i tried to adjust the lrl properly.
It was unable to make it oscillate at 3 Mhz so i replace the capacitor from 68p to 47 pf.
Now output at pin 3,4 is square signal 3 mhz. Signal at point X is triangular 6V but at pin2 is not DC but a not clear triangular. Is it right???

Regards

Correct Geo and this is not right !!!!! Waiting our Colleagues Franco to explain this
Than Geo

[Geo]

Hey why do not you instead of 8 MHz to 3 MHz frequency do you use?
Do you have any particular reason?
Most devices operate below 1 MHz?

Schematic with PLL (4046) works at 3 Mhz not 8 Mhz.
At 8 Mhz works other schematic that uses Xtal.

[reza vir]

Thanks Geo
Which of the three circuits are better looking?
Regards