Lrl from Italy

[mahditala]

Hi fanco here is your LRL. I make PCB to improve it and try to land with some modification on the choice of the frequency search.

And I give you the PCB to do and try.

please part list

[mustefa ubram]

hi franco
how are you.?
happy new years with delay
What do you think about using a diode Varactor 22 Pico alternative?

[FrancoItaly]

I'm well but not yet in Italy, yes the varactor is a good idea, but tuning is not critical, 10 or 20 pF it's the same (in my country), also without capacitor it works well with the only base/emitter capacitance (about 10 pF).
Regards

[mustefa ubram]

also without capacitor it works well with the only base/emitter capacitance (about 10 pF).
Regards

i think is important 22pf capicator .this is for resonance frequency with L1
franco capacitance base/emiter!!!!??????????what is your mean?which transitor ?
please ore explane?

[FrancoItaly]

I mean the base-emitter capacitance of TR2 that is in parallel with C10 through C9.

[wtrk]

Thnaks...

[darkman]

need help plllllllllllllz

Dear FrancoItaly
Thank you for sharing your lrl
I built this one i have silly question how its work ?????
the led is going on and off when i change the value of p3
but p1 and p2 didn't make any change at the led
how to test your lrl ??
how can i know that is working ?

best regard

[FrancoItaly]

With P1 you change the frequency, the better is about 2.5 - 3Mhz (the max frequency for CD4046). With P2 you change the amplitude of the signal, the better is at point (X) (the TR4 collector) a 2 -4 Volt peak to peak, with the scope you must have a good sine curve, not distorted. If you touch the antenna the output signal must decrease. You must have a test field with buried metals (gold, silver or copper) for at least a few months.
Regards

[darkman]

thx Franco bud for all this info's
i will try my best and will tell u the results very soon

Regards

[du6r]

how to use lrl

Dear FrancoItaly
you have great work's with lrl
i just built one of your's with (IC)
on manual test with cell phone the led is lighting up
when i touch the antenna the led is get off
when did i know that the lrl is ready to start locating in range field
now is there any video show how to adjustment the p1 > p2 > p3??? or explain how to work with your lrl ? its seem to me its OK with hand test but what about detect metal
underground dose it working with metals in field range
**** From where can i take the signal line for display circuit (I mean the ic lrl)
how do i now that's the lrl is working in field
should the led light when i but golden ring close to antenna ?
too many question in my mind
can i get your e.mail plz i really need to contact with you
Sorry for my bad English
thank you

[FrancoItaly]

in a previous post I explained how to adjust P1 and P2, P3 is the adjustment of the threshold and also the sensitivity. All LRL only work with metals buried for some time, at least a few months. if you do not have a test field you can go to any place as you can with a metal detector and control every signal obtained with the LRL with the metal detector. If the signal is present for more than 10, 20 meters in the north south direction, his is the compass effect and you must therefore decrease the sensitivity. It should be recalled that the LRL is not a metal detector and therefore does not behave in the same way.
Regards

[darkman]

Just Inquiry .

Now can i connect (display Stage) or (UV meter) To your lrl circuit(with ic) ? if yes , from what point can i get the signal? is it pin2 in ic1?

[FrancoItaly]

The display stage is composed by IC2A (phase amplifier) and IC2B (comparator and led driver). More led drivers or a vu meter must be connected at the IC2A output. At PIN 2 of IC1 there is a pulse signal with duty cicle that changes when the phase changes.
Regards

[mustefa ubram]

hi franco
What is the resonance frequency?(tank circuit)?

[FrancoItaly]

Approximately 150MHz, depends on the values of L1, C11, C10 (negligible) and the base-emitter junction of TR2 (about 10 pf).
Regards