Surf pi 1.2

[Tripalium44]

Hello.

I have a problem with my surf pi 1.2 (I have the right PCB this time). It emits a continuous sound and I can adjust the intensity with the tune potentiometer. However, when I pass a metal target there is no reaction. Do you know where this could be coming from?
For the disc I made 26 turns of enamelled 23awg copper wire (1.7 ohm and 0.48 mh). I then surrounded it with a metal shield (like the YouTube video of the surf detector).
I got the components from a local shop.
Thanks for your help.

[Carl-NC]

Do you have an oscope?

[Tripalium44]

Hello,

yes I have an oscilloscope, where do I plug it in?

[Carl-NC]

The closest wall outlet. Sorry, just kidding. It sounds like the TX is working (you have audio) so start with the preamp, probe the output and wave a target, see if it responds. Check to see if the demod is getting a clock signal. Keep working from the front (preamp) to the back (audio). Also check that all power supplies are proper, especially if there is a charge pump.

[kt315]

my surf pi 1.2 (I have the right PCB this time)

long board? has mistakes. everyone doing long board begins a talk from 'HELP SOS PROBLEM' and never i see happy end.
do you need a link at the forum thread seeking?

[boilcoil]

That sounds you did not make a gap in the coil shield.

[lxs17757414132]

I bought a fake chip last month but the coil didn't work. I tried replacing the lf357n CD4011 CD4046 board with the lf357 one and it worked fine. I also replaced the 4011 and it worked fine

[Tripalium44]

Hello. I'm new to electronics and I'm using this project to learn.
Where should I connect (pre amp etc) and what value should I have?
What is a charge pump?

Do I have to make a hole in the coil shield? How do I do this?

I will try to change the integrated circuits to see.
Thanks