felezjoo PI(the best pulse induction metal detector that I made until now)

[Altair]

Thank useus!

[useus]

I am very happy with the operation of the metal detector, air test playing with the parameters finds 1 euro at 34cm, 0.2 grams about small gold medal 5cm. When I get the bms for the batteries immediately field tests!

I correct myself... 0.2 grams about small gold medal 10,5cm

[ionut_mtb]

Hello,

Felezjoo pi finished, i use ca3130ez instead of lf357, detector is discriminating good, but depth is not so great. Aprox 20cm for a coin. I still need to do more testing and adjustments. As a coil, for now, i have a 30cm diam bundle alphawire, aprox 300uH and less than 1ohm, rg58 cable, shielded with conductive fabric cloth tape.

I’m not sure about some things:
I had read somewhere that metalic coil connector make problems.
I also want to add 2 aluminium plates paralel to the board for shielding.
rg58 is enough for the coil cable or i need to add 2wire cable and shield connected to ground.?
i want to add onboard isp connector for writing atmega 328 without taken it out. Jumper somewhere? Or i just rewrite with the detector on?

[useus]

Hello,

Felezjoo pi finished, i use ca3130ez instead of lf357, detector is discriminating good, but depth is not so great. Aprox 20cm for a coin. I still need to do more testing and adjustments. As a coil, for now, i have a 30cm diam bundle alphawire, aprox 300uH and less than 1ohm, rg58 cable, shielded with conductive fabric cloth tape.

I?m not sure about some things:
I had read somewhere that metalic coil connector make problems.
I also want to add 2 aluminium plates paralel to the board for shielding.
rg58 is enough for the coil cable or i need to add 2wire cable and shield connected to ground.?
i want to add onboard isp connector for writing atmega 328 without taken it out. Jumper somewhere? Or i just rewrite with the detector on?


[ATTACH]47654[/ATTACH]
[ATTACH]47655[/ATTACH]

to me the metal connector does not create any problem. I use a high quality microphone cable. The coil should not be shielded.
There is the non-counter hex, you find it in the page 76 so there is no need to reprogram.
you must use the original LF357 for correct debug values. however try to physically remove the shielding, not only disconnect it and see if the debug values are close to 300 700 800. You should bring the coil close to 350uh 0.9 to 1.1 ohm and absolutely no shielding.

[Rodelio]

Hello folks.
Ther's something i found about ATmega328 and the low fuse (full swing cristal oscilator) F7 in the case of felezjoo projet.
Seems to be that after the year 1915 the factory doe's not support any more to ATmega328p-pu this function.
So you can check it out in this link (https://youtu.be/93dSfEczqgk)...
I hope this can be ussefull to all who work in the felezjoo MD.
Regards to all.

[Rodelio]

Hello,

Felezjoo pi finished, i use ca3130ez instead of lf357, detector is discriminating good, but depth is not so great. Aprox 20cm for a coin. I still need to do more testing and adjustments. As a coil, for now, i have a 30cm diam bundle alphawire, aprox 300uH and less than 1ohm, rg58 cable, shielded with conductive fabric cloth tape.

I?m not sure about some things:
I had read somewhere that metalic coil connector make problems.
I also want to add 2 aluminium plates paralel to the board for shielding.
rg58 is enough for the coil cable or i need to add 2wire cable and shield connected to ground.?
i want to add onboard isp connector for writing atmega 328 without taken it out. Jumper somewhere? Or i just rewrite with the detector on?


[ATTACH]47654[/ATTACH]
[ATTACH]47655[/ATTACH]

I use ca3130 too and i have the same problem.
Ca3130 overflow debbugs. Lf356 get closer but no perform very well.
Lf357 have 20mhz gain bandwidht & 50 v/us slew rate. Lf356 have gain bandwidht of 12mhz & 12 v/us lew rate.
I'm sure that the hex file felezjoo was writing acording to lf357 parameters.
I agree with useus.

[useus]

This morning I did the first test on a mix of rocky terrain and ground on strips, the metal detector is extremely sensitive! I had to lower the sensitivity to 10 to avoid false signals and put ground off on the slightly damp grass. I have to understand the settings well because intregr w at 48 it doesn't give me problems instead if I lower it to 44 gives me false signals. Only found various hunting cartridges, it was once a hunting area. I could not get where I wanted because from afar (fortunately) I saw wolves and I **** on myself Maybe next time, maybe with friends

[Altair]

useus,
I think is better to add a shield to the coil...

[useus]

useus,
I think is better to add a shield to the coil...

Shielding creates big problems in the search

[dom44]

if you use graphite conductive paint should not be a problem with shielding, wont interfere with the magnetic signal.

[useus]

Graphite causes continuous ground noise.

However the metal detector without shield works well, just knowing how to set the parameters correctly

[lamoiz]

Good evening everyone
I also built a Felez to try.
it works well .. except the disc .... no ferrous ... no ferrous ... no ferrous .... pfff .I tested the monocoil, then the dualcoil's ... no disc..the values of dual are:
360 mh 108pf 1.7r = 980r damp for the first, and 380mh 78 pf 0.93r = 1.1k damping for the second.
the delay measurement is 12 for the 1st and 11 for the 2nd.
What are the values you get with your coils?
Thank you

[useus]

I have not found information, out of curiosity this value to what it refers to?


however, continuing the discussion of the other day, last evening I did another test on the field, I am limited to keeping the sensitivity to 10 because with a higher value it plays any type of terrain but I still found 20 euro cents at around 15 / 18 cm underground. I believe that as a depth it is good even with low sensitivity, I should like to say if I'm wrong

[sbalio1]

this is the level of the battery. At 14.5 gives error coil.
By touching the top button, numbers indicating the size of the metal will appear. The larger the size, the more these figures change significantly compared to a small size of metal.

[useus]

this is the level of the battery. At 14.5 gives error coil.
By touching the top button, numbers indicating the size of the metal will appear. The larger the size, the more these figures change significantly compared to a small size of metal.

Thanks!