Clone Chance Help

[Nickolaos]

Hello and Greetings from Greece. Its my first post so if i make a mistake please understand that i mean no harm. I recently built the clone chance as described by its Designer. The detector does find metals but i cant get it work quiet when there is no metal presence. It clicks randomly. My coil is 350uh 2 ohm 25cm diameter. Any suggestions? Thanks in advance.

[WM6]

Can you post video of such "Chance" behavior?

[Nickolaos]

I will have posted the video by tomorrow afternoon.Thanks for your quick reply.I will also post pictures from the main board and the coil.

[Nickolaos]

https://www.youtube.com/watch?v=upSz...ature=youtu.be Here is the video and the picture from the front side of the detector

[WM6]

This PCB need to be thoroughly checked on short joint or possible breaks.

Did you clean all resin residue from soldering joint after soldering?

How did you construct coil? Chance is not tolerable to every coil design as
some other PI detectors.

[Nickolaos]

Yeah The PCB is checked thorougly. The output pulse is as shown by the Designer. Output from OP37 and output from ADC seems correct. The coil and the dumping resistor might be a problem.The coil is around 20 turns.I used rg58 coax as feedline. The dumping resistor is 1K.

[qute1]

did you zero it ? button 2?

[kt315]

you must learn author coil at first. if you see 'disc' advantages in PI you must copy detail-in-detail the coil. sorry but this PI tipo with micro is strong sure tuned by program under
only one coil. look felicjo for example people write again and again that this detector is not working, while the author detector works good.
the answer is evident - coil.
Andy uses backet tipo coil, you use something non-fast. inconsistency.

[Nickolaos]

I have read on another forum that it works with any coil around 400uh. I will see some details because i suspect that something happens with the ADC. I Will also start making the backet coil. I dont have something to loose.

[kt315]

you did to loose



I have read on another forum that it works with any coil around 400uh.
--
another forum is a site of Andrej Fiodorov?

[Nickolaos]

Yeah its wasnt from his forum. Many things on the internet are false and generic. I will try to build this coil. Kind of time consuming but i hope it will solve my problem.

[baum7154]

The original Chance coil shown in this thread is OK for coins and other large items but will not operate below about 20us Guard Interval and is useless for small gold detection. The 3DSS COIL with 300 to 330uh is much better for gold and other small fast targets.

Dan

[kt315]

Yeah its wasnt from his forum. Many things on the internet are false and generic. I will try to build this coil. Kind of time consuming but i hope it will solve my problem.

you have to learn what is fast coil and do fast coil. much info on this forum and we constanly tell about that.
try use tags: basket coil, litz coil, fastest coil.

[6666]

The original Chance coil shown in this thread is OK for coins and other large items but will not operate below about 20us Guard Interval and is useless for small gold detection. The 3DSS COIL with 300 to 330uh is much better for gold and other small fast targets.

Dan

I find it interesting that Andys coil is apparently slow even though its a flat spiral wind
and the wires are apart
but when you look at another flat spiral wind it only has very low capacitance (15pF)
but the wires are close together.

[green]

I find it interesting that Andys coil is apparently slow even though its a flat spiral wind
and the wires are apart
but when you look at another flat spiral wind it only has very low capacitance (15pF)
but the wires are close together.



[ATTACH]43508[/ATTACH]

I also find it interesting and wonder why it would be slow