Hi All
I post here the complete schematic of my last Lrl that works in no-motion mode. I have not yet definitive proof of how it works in real field, but it works perfectly in my test field. It is essential to have a field where do the tests. In my case I buried 5 silver coins and after about a month already they were revealed by my Lrl. Then I buried a small gold bracelet and also after a few weeks was detectable by my Lrl, although with less intensity. I must also remind you that the "phenomenon" is not distributed evenly around the target but is greater in the North South direction and over the target there is no signal  and this confirms what Esteban said. The most crical part is the sensor stage, it’s derived from a bug sniffer that I have realized on a double side pcb consisting of six parallel rows on each face. I put this circuit in place of the front end of a non well working Lrl and this instrument was able to reveal the targets in my test field. The output was a stable DC voltage and I thought
that the stage was an oscillator but also sensible to external signals. The frequency was about 5 Mhz but by connecting the oscilloscope the oscillation
stopped. I think that the oscillation is caused by a parasitic coupling between the TR3 collector and the TR1 base by means of the  2 strips in the lower side, one under the TR3 collector and the other under the TR1 base.  The proof of this is that with another printed board with the inferior strips not well aligned with superior strips there was no oscillation and I made this circuit working by putting a small capacitor ( 1 pF) between the 2 inferior strips and by connecting  the TR3 collector to the corresponding inferior strip.  To verify the proper oscillation you have to touch the input and the oscillation must decrease, if not the case the oscillation is only  between the TR2 and TR3 stage and capacitors C5, C6, C7  have a value too large. If you have no oscillation by varying C6 try for C5 470 pF or 560 pF.  The range between no oscillation and max signal is few picofarad and this make very difficult to calibrate the stage. The presence of the "phenomenon" is revealed by an increase of the signal. The “heart” of the stage is around TR1, part of the oscillation signal go to ground by capacitors C1 and C2 and inductance L1 and the “phenomenon” reduces the signal that goes to ground and then a signal enhancement at output of the stage. The stylus antenna picks up the signal that at least partly  it’s a E-field signal. The length of the antenna is approximately 30 cm and you can also use a brass tube. The optimal voltage at the output is about 3V that is amplified and inverted about 3 times by IC3A, P2 is the sensitivity control and IC3B is a comparator that drives a led and a buzzer.  IC2A is a comparator that drives the oscillator around IC2B, when the battery voltage goes under 16V the red led flashes.