Lrl from Italy

[daniel]

Did tests today with buried metal (Iron rods that are over 30 years buried) but no signal at all. Tried both antennas stylus and mono coil. Nada nothing :-( thats a bit of frustrating. Only TV and fluorescent lamps works.

I 've also put a variable capacitor for stylus antenna C11 (5 - 27pf) to see if something changes but its the same it doesnt work for me.

Anyone here with positive results? Did you found something buried with this LRL? Im very interested because maybe I build something wrong.

[mustefa ubram]

Hi freind.
i think frnco told this lrl working only for non magnetic metals same copper or solver.dont work for magnetic metal

[Geo]

Franco do you remember how much is the signal at emitter of TR1 at schema with xtal 8Mhz??
I constructed a new ground plane pcb but something is not going right.

Regards

[FrancoItaly]

Hi Geo,
The important thing is that there is a signal at the output of TR1, about 2V - 5V, as I mentioned with the quartz disconnected there should be no DC voltage signal at the output, and with quartz connected you need to choose C2, C3, C4 for a DC signal (about 2-5V). The best solution is a double-sided PCB with the lower face connected to ground and with the components soldered on the top face.
Regards

[mustefa ubram]

HI FRANCO
HOW ARE YOU DEARE FREIND?
What is the minimum and maximum voltage output in ic1a?
what is voltage range in output ic1a?

franco please reply to this post

[FrancoItaly]

Hi Mustefa,
If you refer to PLL schematic we have IC2A, not IC1A and the important thing is that at PIN 2 of IC1 there is a DC voltage 1-6V (measured with a DC voltmeter, with scope we have an impulse segnal). The IC2A output must be regulated by P3 for better threshold.
Regards

[FrancoItaly]

Hi daniel,
As mustefa said the Lrls do not respond to iron target and this is a good luck... For me it works well 2 or 3 turns for L1 with 22pF and this for my country and in Switzerland, you can try 4 or more turns but remember you must have a long time buried metal for test.
Regards

[FrancoItaly]

Hi mustefa,
I don't see IC1A, what it you're referring to?
Regards

[mustefa ubram]

Hi Mustefa,
If you refer to PLL schematic we have IC2A, not IC1A and the important thing is that at PIN 2 of IC1 there is a DC voltage 1-6V (measured with a DC voltmeter, with scope we have an impulse segnal). The IC2A output must be regulated by P3 for better threshold.
Regards

Hi franco my porpose is 8mhz crystal osilator tape lrl.i want out put voltage range in the pin 1 ic1a (358?
thank you very much

[Geo]

Hi Geo,
The important thing is that there is a signal at the output of TR1, about 2V - 5V, as I mentioned with the quartz disconnected there should be no DC voltage signal at the output, and with quartz connected you need to choose C2, C3, C4 for a DC signal (about 2-5V). The best solution is a double-sided PCB with the lower face connected to ground and with the components soldered on the top face.
Regards

Hi Franco.
Thanks for your answer.
I made a double side pcb but i have the upper face connected to gnd, i think there is not problem. I adjusted the capacitors so to have a dc out of 4.1 v but when i touch the antenna the out goes up, don't lowers as you wrote at other thread. Who is your opinion?????

Regards

[FrancoItaly]

Hi Geo,
This case has never occurred in my lrls (I've built a dozen lrls) for some unknown reason your LRL works in reverse mode. Try it out on the field and see how it behaves with the phenomenon, basically touch the antenna is an empirical way to test the LRL.
Regards

[mustefa ubram]

Hi Franco.
Thanks for your answer.
I made a double side pcb but i have the upper face connected to gnd, i think there is not problem. I adjusted the capacitors so to have a dc out of 4.1 v but when i touch the antenna the out goes up, don't lowers as you wrote at other thread. Who is your opinion?????

Regards

HI GEO
if you made lrl 8mhz tayp.Please measure the output of IC1a.I want the minimum voltage in stand by system and maximum voltage When it reacts.i want for connect to the micro?
thant you

[FrancoItaly]

Hi Mustefa,
The pin 1 of IC1A must be at a more low voltage of the connection point between R5 and R6, and in this way all the LEDs are off and this is achieved by adjusting P1. If you want a more soft regulation of P1 you have to add a resistor on the ground side and must be calculated in such a way that with P1 rotated fully clockwise to the first LED is lit and the buzzer is on. You have to remember that adjusting P2 (gain) varies the output of IC1A and then you must also adjust P1.
Regards

[mustefa ubram]

Hi Mustefa,
The pin 1 of IC1A must be at a more low voltage of the connection point between R5 and R6, and in this way all the LEDs are off and this is achieved by adjusting P1. If you want a more soft regulation of P1 you have to add a resistor on the ground side and must be calculated in such a way that with P1 rotated fully clockwise to the first LED is lit and the buzzer is on. You have to remember that adjusting P2 (gain) varies the output of IC1A and then you must also adjust P1.
Regards

thank you franco
I want to connect the output voltage to the micro.maximum input voltage for micro is 5v.I want to know the maximum and minimum output voltage for potentiometer designed for voltage 5V.
please help me?
thank you

[FrancoItaly]

Hi Mustefa,
I think that the best solution is to power IC1 with 5V instead of 12V, adjusts the output of the sensor stage to approximately 2V and put one 5V zener to non inverting input of IC1A and ground.
Regards