My take on the HH2

[waltr]

You right, using 8-pin PIC is very very easy, i will try it.
Yes, Mr. FatBob has used CD4046. As you see, there are two TL072 for generating two fixed tone (i think). Now suppose that i remove the two amp and out of HH is directly connected to Pin 9 of CD4046.
Do you think we will have different tones for different metals, size or etc?! I think GPX audio isn't using two fixed tone, i think it's a range frequency.
[ATTACH]55049[/ATTACH]

Maybe not for different metals but will have different tones for targets with different TCs.
PI detectors can not disc different metals just different Time Constants.

[h9361]

You right, using 8-pin PIC is very very easy, i will try it.
Yes, Mr. FatBob has used CD4046. As you see, there are two TL072 for generating two fixed tone (i think). Now suppose that i remove the two amp and out of HH is directly connected to Pin 9 of CD4046.
Do you think we will have different tones for different metals, size or etc?! I think GPX audio isn't using two fixed tone, i think it's a range frequency.
[ATTACH]55049[/ATTACH]

Dear Walter
Please forgive me for my questions.
Can you tell me application of the two 100K pot in Mr. FatBob (before CD4046, for TL072)? When time we should use the Pots?

[Carl-NC]

The schematic has very obvious errors. Those pots won't do anything.

[h9361]

The schematic has very obvious errors. Those pots won't do anything.

Thanks dear Carl.
Do you think we can use its CD4046 for HH1 audio part, (without its pot and TL072)?

[waltr]

I unfortunately did not look at that schematic close and it has been a few years since I played with 4046 VCO.
I dug through my archives and found this:

This is the one I played with. Mickstv is a user here on Geotech who posted this. Search for original thread about this VCO.

Other wise you simply need to build and experiment (well you need to do that anyway).

[Carl-NC]

Do you think we can use its CD4046 for HH1 audio part, (without its pot and TL072)?

Yes

[h9361]

I unfortunately did not look at that schematic close and it has been a few years since I played with 4046 VCO.
I dug through my archives and found this:[ATTACH]55062[/ATTACH]

This is the one I played with. Mickstv is a user here on Geotech who posted this. Search for original thread about this VCO.

Other wise you simply need to build and experiment (well you need to do that anyway).

Very thanks dear Walter.
I have a request, do you remember time delay of your code for main, EFE and GB delay?

[h9361]

Thank you dear Carl.
I read your book IMD, it's very nice and i learned vey much about metal detectors.

[h9361]

Dear Walter
Please forgive me for my primary questions.
I'm going to use 8R, 0.5w speaker. Please see attached, do you think which of method is better?
I remember, LM386 (gain 20 ) is very powerful than such speaker and i have not good experience with the amp.

[h9361]

I unfortunately did not look at that schematic close and it has been a few years since I played with 4046 VCO.
I dug through my archives and found this:[ATTACH]55062[/ATTACH]

This is the one I played with. Mickstv is a user here on Geotech who posted this. Search for original thread about this VCO.

Other wise you simply need to build and experiment (well you need to do that anyway).

Can you tell me which point of HH1 must be connected to C8?

[waltr]

Dear Walter
Please forgive me for my primary questions.
I'm going to use 8R, 0.5w speaker. Please see attached, do you think which of method is better?
I remember, LM386 (gain 20 ) is very powerful than such speaker and i have not good experience with the amp.
[ATTACH]55063[/ATTACH]

Any of these should work. You need to build them and test to decide which is best for you.

Can you tell me which point of HH1 must be connected to C8?

Output of the SAT stage.

[h9361]

Any of these should work. You need to build them and test to decide which is best for you.


Output of the SAT stage.

Thank you.
Is that correct?

[Mdtoday]

Thank you.
Is that correct?
[ATTACH]55067[/ATTACH]

That is correct

[waltr]

Thank you.
Is that correct?
[ATTACH]55067[/ATTACH]

That is correct

That could be used but is the Integrator output.
The SAT output is what I would use,, at TP9.

You can try both and see which you like better.

[h9361]

That could be used but is the Integrator output.
The SAT output is what I would use,, at TP9.

You can try both and see which you like better.

Thanks dear walter.
I want to build Mickstv's Audio part. He used JFET PMBF4393 but i can't find the FET in our country. Do you think i can use BF256 as its replacement? Can you introduce me some through hole equivalent?