Lrl from Italy

[FrancoItaly]

Originally Posted by toorani

Hello dear franco
I hope you always be healthy
I found the problem circuit,Tr2 transistor was faulty.
The collector voltage is now: tr2 2.8 volt ,tr3 4.5 volt, tr4 4.5 volt
why the collector voltage tr2 is 2.8 volt?
Without the quartz, the output voltage is zero(emiter tr5) and with quartz is 4.1 volt
signal Emitter tr1 is 8 Mhz 2.4 volt pic to pic,Of course capacitor c1 is Two parallel capacitors 560p.
capacitor c13 is 200 nf and c14 is 100 nf but why The output voltage does not exceed 4.1 volts?
capacitor c2,c3 and c4 is 1.8 pf

Thank you very much for your guide

4.1V is ok. 2.8V at TR2 collector voltage is ok, as here the signal is very small. If touching
the antenna the output changes the sensor stage is ok.

[toorani]

Originally Posted by FrancoItaly

4.1V is ok. 2.8V at TR2 collector voltage is ok, as here the signal is very small. If touching
the antenna the output changes the sensor stage is ok.

hi franco dear
with touching the antenna, How much output should change ?
Thank you very much for your guide

[FrancoItaly]

Originally Posted by toorani

hi franco dear
with touching the antenna, How much output should change ?
Thank you very much for your guide

it's not critic, about 10mV - 1V or more.

[toorani]

[QUOTE=FrancoItaly;156419]it's not critic, about 10mV - 1V or more.[/QUOTE


Thank you very much for your guide
with touching the antenna,the output will increase by about 0.4 volts

[toorani]

[QUOTE=toorani;156420]

Originally Posted by FrancoItaly

it's not critic, about 10mV - 1V or more.[/QUOTE


Thank you very much for your guide
with touching the antenna,the output will increase by about 0.4 volts

In your opinion, with these conditions my lrl is ok?
Can I put it inside the box?
The box with aluminum foil does not create capacitive capacities?
What is lrl reaction to the target?
Or, by placing the L1 vertically, the sensitivity to the north pole and south will decrease?

[FrancoItaly]

[QUOTE=toorani;156421]

Originally Posted by toorani

In your opinion, with these conditions my lrl is ok?
Can I put it inside the box?
The box with aluminum foil does not create capacitive capacities?
What is lrl reaction to the target?
Or, by placing the L1 vertically, the sensitivity to the north pole and south will decrease?

yes but if is necessary you may increase gain by decreasing R17 (from 150K to 47k), by increasing P2 (from 470K to 1M)
You can put the lrl in the box.
The shield do not disturb.
The target increases the DC signal (sensor stage output)
I think that the L1 place is not important. Too much gain causes the compass effect.

[toorani]

[QUOTE=FrancoItaly;156422]

Originally Posted by toorani

yes but if is necessary you may increase gain by decreasing R17 (from 150K to 47k), by increasing P2 (from 470K to 1M)
You can put the lrl in the box.
The shield do not disturb.
The target increases the DC signal (sensor stage output)
I think that the L1 place is not important. Too much gain causes the compass effect.

hi franco dear
What do you mean by r17?
Is the same r1 in the display stage?
Thank you so much.

[FrancoItaly]

[QUOTE=toorani;156423]

Originally Posted by FrancoItaly

hi franco dear
What do you mean by r17?
Is the same r1 in the display stage?
Thank you so much.

This is the schematic, yes I refer to display stage (3 leds)

[toorani]

Originally Posted by FrancoItaly

watch these videos:

https://www.youtube.com/watch?v=lp35Ly8Cw1Q

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

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

I ask Panos Pappas few details on the type of metal and even distance is revealed. To Mustefa I said: good work.

hi franco dear
Should lrl have two antennas?
I installed an antenna one meter.
Are the leds turned off be exactly above the target?
Thank you so much.

[FrancoItaly]

Originally Posted by toorani

hi franco dear
Should lrl have two antennas?
I installed an antenna one meter.
Are the leds turned off be exactly above the target?
Thank you so much.

An antenna works well.

Yes the signal goes off about above the target.

[FrancoItaly]

Hi Zixelll,

I respond here because your inbox is full:

The stylus antenna is better because you can increase the sensitivity by lengthening it.

This voltmeter is not suitable, as I see it has 500V full scale. My lrl is designed for led display.

[afshin]

Hi dear franco
Thank you for sharing your lrl.
What is your orginal pcb size?
Thank's

[toorani]

hi dear franco
I put lrl in the box.
My lrl responds to some things,for example:
Thermal glue,Refrigerator engine,Lamp,Gas stove lighters,Oscilloscope.
In your opinion,This is the correct performance?
Thank you very much for your guide

[FrancoItaly]

Originally Posted by afshin

Hi dear franco
Thank you for sharing your lrl.
What is your orginal pcb size?
Thank's

These are roughly the original dimensions, however the dimensions are not critical, especially if you use the double-sided pCB.

[FrancoItaly]

Originally Posted by toorani

hi dear franco
I put lrl in the box.
My lrl responds to some things,for example:
Thermal glue,Refrigerator engine,Lamp,Gas stove lighters,Oscilloscope.
In your opinion,This is the correct performance?
Thank you very much for your guide

My lrl has a high gain amplifier and any rf source may disturb, then this behavior is normal.

[toorani]

hi dear franco
Is it possible to reduce the Voice of buzzer?
Thanks dear Franco.

[FrancoItaly]

Originally Posted by toorani

hi dear franco
Is it possible to reduce the Voice of buzzer?
Thanks dear Franco.

There are several possibilities:
- use another type of buzzer.
- put a resistance in series to the positive or negative of the buzzer, the value is to be tested.
- put the buzzer inside the box, in this way the sound is attenuated.
- I use a switch to exclude it.

[afshin]

Hi mr fracco
And thank you for members guidance
Mr franco what kind of adjusting threshold is true?
I meaning is that how we adjust LED threshold OFF towards surrounding?
1-when anten is front and horizontal?
2-or anten is to the sky and vertical?(and neutralization of sky effect)
3- or else way?
What way is best and standard to searching and detecting targets?(Hi sensitivity and correct way)
Thank's

[FrancoItaly]

Originally Posted by afshin

Hi mr fracco
And thank you for members guidance
Mr franco what kind of adjusting threshold is true?
I meaning is that how we adjust LED threshold OFF towards surrounding?
1-when anten is front and horizontal?
2-or anten is to the sky and vertical?(and neutralization of sky effect)
3- or else way?
What way is best and standard to searching and detecting targets?(Hi sensitivity and correct way)
Thank's

If the lrl is well adjusted there is no compass effect, normally the antenna must be parallel to the ground and the threshold must be adjusted to get the first LED off, approaching the target you need to slightly tilt the antenna downwards (to get the maximum signal), the signal disappears completely around the vertical of the target. All this moving in the north / south direction, in this way the sensitivity is maximum.

[afshin]

Thank's mr franco
But in this way ( parallel to the ground and then adjusting the threshold)when I move the antenna to left and right or downward or upward the LED be ON.Does my lrl work normal and correct or not?
Thank's

[FrancoItaly]

Originally Posted by afshin

Thank's mr franco
But in this way ( parallel to the ground and then adjusting the threshold)when I move the antenna to left and right or downward or upward the LED be ON.Does my lrl work normal and correct or not?
Thank's

If there is not a target Led must be off, if LED is on there is compass effect and/or sky effect, then the gain is too much.

[payam20]

hi franco
after more than 2 year working on your lrl !! i found some thing weird !

i have increased gain (now i am using 4.7n for c13 & c14 ) without self oscillating .(but with a little change )
but no way to increase range from 15 meter i have reached this range with half gain! (15m from north to south and south to north half of range . other directions too weak !) and it senses some places without any metals some times !

antenna length 83cm . sensor voltage around 3.5 volt(decrease it from 3.5 volt will be too hard to work with ! it will be too noisy and increasing it will decrease range .

test for a copper bowl in around 80 cm for more than 5 years buried . (almost same result in real test )

[toorani]

hi dear franco
I put lrl in the box,In terms of conductivity, grand circuit and box is connected to the antenna,Is that right? I feel less sensitive.
http://uupload.ir/files/prks_photo_2...9_11-24-16.jpg

now c1 is two Parallel Capacitor 560p and signal emiter tr1 is 2.4 volt pic to pic 8mhz and voltage out put(emiter tr5) is 4.5 volt but With Change c1 to 560p signal emiter tr1 is 3.5 volt pic to pic 8mhz and voltage out put(emiter tr5) is 5 volt,In your opinion,Which mode is better?
Thank you so much.

[toorani]

Originally Posted by toorani

hi dear franco
I put lrl in the box,In terms of conductivity, grand circuit and box is connected to the antenna,Is that right? I feel less sensitive.
http://uupload.ir/files/prks_photo_2...9_11-24-16.jpg

now c1 is two Parallel Capacitor 560p and signal emiter tr1 is 2.4 volt pic to pic 8mhz and voltage out put(emiter tr5) is 4.5 volt but With Change c1 to 560p signal emiter tr1 is 3.5 volt pic to pic 8mhz and voltage out put(emiter tr5) is 5 volt,In your opinion,Which mode is better?
Thank you so much.

also,now with Touch antenna,out put tr5 10mvolt Increases,Is that right?

[FrancoItaly]

Originally Posted by toorani

hi dear franco
I put lrl in the box,In terms of conductivity, grand circuit and box is connected to the antenna,Is that right? I feel less sensitive.
http://uupload.ir/files/prks_photo_2...9_11-24-16.jpg

now c1 is two Parallel Capacitor 560p and signal emiter tr1 is 2.4 volt pic to pic 8mhz and voltage out put(emiter tr5) is 4.5 volt but With Change c1 to 560p signal emiter tr1 is 3.5 volt pic to pic 8mhz and voltage out put(emiter tr5) is 5 volt,In your opinion,Which mode is better?
Thank you so much.

The shield must be connected to ground, the antenna must be connected only to C9/C10.
As regard to C1, there is no difference because the sensor stage gain does't change, but if the gain should be insufficient, C1 must be decreased, in this way the amplification of TR3 / TR4 can be increased. Another way is to decrease C2 / C3 / C4 (instead of C1). Keep in mind that the 8Mhz signal is only a carrier that is "modulated" by the phenomenon.