PI Audio

[h9361]

correct. You can also connect to the other side of C19 at IC8

you don’t need anything past the SAT section

ill leave you to it for now, I’m off for some sleep

Cheers

Thanks dear Mdtoday for your guiding.
I will test and tell here my result.

[h9361]

Hello
Dear Mdtoday.
I changed connection point of my HH1, my problem solved and now i have a constant audio.
Thank you my friend for your tip.

[h9361]

Hello
Dear Mdtoday.
I hope you are fine.
I have a question about Mickstv audio.
Is it possible to change THD pot smooth?
For exp, i change my THD pot from silence to audio, i have a noisy audio. So, i have to increase my THD pot to have a clear audio.
For a better understanding, consider THD pot of GPX, it is very very smooth. Do you have any suggestion for reaching such smooth THD?
Thanks.

[Mdtoday]

Hello
Dear Mdtoday.
I hope you are fine.
I have a question about Mickstv audio.
Is it possible to change THD pot smooth?
For exp, i change my THD pot from silence to audio, i have a noisy audio. So, i have to increase my THD pot to have a clear audio.
For a better understanding, consider THD pot of GPX, it is very very smooth. Do you have any suggestion for reaching such smooth THD?
Thanks.

Check your power supplies are well decoupled, although it is most likely external noise, possibly mains power, RF and the like. Also, don't forget to check the simple things like a bad potentiometer.
If it is constant motor boat type noise, as in the audio pitch and volume is hunting up and down, then you can try adjusting the TX frequency up and down a little by 1 or 2 Hertz to reduce that particular problem.
If it is higher frequency hash type noise, then you will need to reduce the circuit gain a little but note, this won't always fix the problem.
It's always troublesome to test a PI detector on the work bench given the usual array of EMI present in most homes.

cheers

[h9361]

Thanks for your answer.
I tested it more and more out of city, clear of any noise.
Do you think i should use a multiturn for THD pot?

[Mdtoday]

Thanks for your answer.
I tested it more and more out of city, clear of any noise.
Do you think i should use a multiturn for THD pot?

No, it's not required IMO.
Has this problem just occurred, or has it always been there?
If it was stable and you have made changes then the problem appeared, then you need to back track
Board layout, faulty component, component choice, bad solder joints...
Please post a schematic and photo of your build, then we can see what you have and maybe we can help more.
You can still test most PI designs in house but you need to at least do it away from computers, tvs routers etc.
If you have a variable frequency TX and variable gain RX, then you have a better chance of reducing the noise problem.
I haven't been following your thread much so I'm not aware of all the experimenting you have done, so can't really comment much more.

cheers

[h9361]

No, it's not required IMO.
Has this problem just occurred, or has it always been there?
If it was stable and you have made changes then the problem appeared, then you need to back track
Board layout, faulty component, component choice, bad solder joints...
Please post a schematic and photo of your build, then we can see what you have and maybe we can help more.
You can still test most PI designs in house but you need to at least do it away from computers, tvs routers etc.
If you have a variable frequency TX and variable gain RX, then you have a better chance of reducing the noise problem.
I haven't been following your thread much so I'm not aware of all the experimenting you have done, so can't really comment much more.

cheers

Before everything, i must thank you for your guiding because the schematic is working nice.
Dear Mdtoday, i'm interesting to change the schematic for detecting target timing.
Suppose that i detected a target, so my audio has a action and then will go to its base tone (no changing frequency and level position).
If you see carefully, going from changing frequency/level position (detecting target) to no changing frequency/level position (no target) has a high speed! If you see audio of GPX, the speed is slow and soft! Do you think we can reach such soft audio like GPX? Do you have any suggestion to change and to test in circuit?
Thanks.

[scrungy_doolittle]

As you may know, the whites 6000 di figures out a target, by taking the log-rhythms of the two channels, and then subtracts them, resulting in an analog signal that gives the ID. I wonder if this circuitry would be capable of doing something similar.

[kt315]

follow way MET_DET\ProScan_Impulsowy Wykrywacz Metali\kret + modul

https://drive.google.com/file/d/1Czc...ew?usp=sharing

[Emersonpaz]

I made the project from mickstv I'm using it on the Polish pi https://youtu.be/RDV93ZdeGhk

[aymenrhouma]

I made the project from mickstv I'm using it on the Polish pi https://youtu.be/RDV93ZdeGhk

Can you share the diagram and upload it in Grbr or sprint layout

[bernte_one]

follow way MET_DET\ProScan_Impulsowy Wykrywacz Metali\kret + modul

https://drive.google.com/file/d/1Czc...ew?usp=sharing

Hi KT315
can you renew this link?

[h9361]

Looks ok, now go build it and try it out, build the power supply and audio amp first, make sure it works, then add Mickstv circuit, do it in stages, test each stage then move to next one. Dom44 did a through hole version, others have built that one too, he used an Lm386.
As Mickstv and others have said, the circuit works, so why not build as per the schematic posted first, give it a try then start changing things.
It is the best way to start, try not to complicate things, I’m sure you will do just fine.

Hello
Dear Mdtoday
I hope you are in a good health.
Before everything, thank you for your supporting and please forgive me for my questions.
My friend, as you know, i added the GB (based four Sampling) part to my HHD (attached general schematic). Then i added your Audio to it.
Both of them is working nice but i have a strange problem with audio. As you know, the audio works based on both pitch and volume level. For exp, if a target is closed to coil, both volume and frequency will be changed. Similarly, if target is far from coil, only its frequency will changed. My problem is in middle of the distance, exactly edge of called close distance. In this distance, my audio part produces a strange audio, like a noisy signal. It acts like a non-motion mode but its sound is a very very noisy, instead of a clear audio for closer targets. I think the audio part can't make a decision for doing both pitch and volume or only pitch changing. So, it compounds them incorrectly. For solving the problem, do you have any suggestion for the schematic? which part of the schematic should be edited? Remember that i have no problem with high and close distance, only middle distance is problem

[Nightryder]

I made the project from mickstv I'm using it on the Polish pi https://youtu.be/RDV93ZdeGhk

I redrew the pcb with thicker tracks & more space between them to make it easier for home etching.

Credits and thanks goes to Emersonpaz of course. I highly recommend to visit his YouTube channel and check out the link he provided first.

[Nightryder]

I redrew the pcb with thicker tracks & more space between them to make it easier for home etching.

Credits and thanks goes to Emersonpaz of course. I highly recommend to visit his YouTube channel and check out the link he provided first.

I had to fix two mistakes which are shown in the pic attached with the corrected PCB.