SBG-PID

[Andi68]

Carl, what's your opinion on this circuit?

[Carl-NC]

Always hate to see such awkward way of drawing schematics.
Purposely messed up to the level of being completely confusing.

I was going to say the same, it looks as if someone drew it just so it would fit in a minimum size square.
Thanks for the redraw.

[scs]

https://www.geotech1.com/forums/atta...7&d=1556082873 schematic is o. k. Ground Ballanse and Discriminator simmular in Goldscan 5.Detector is tested in normall ground.

[bernte_one]

@ andi build the latest clone pi and have fun

https://www.geotech1.com/forums/showthread.php?24816-Clone-PI-W-komplete&highlight=clone

on our soils we need permant gb autune function and some kind of crap filter


if you search in the norwegian backwoods far away from any settlement you can use a high power analog pi for meteorite hunting

[Andi68]

Which schematic can I now rely on, which is faultless ?

[6666]

Sacho, I am very interested in the GEB, when you tested the circuit does it balance out highly mineralised ground ? thanks.

[scs]

Scheme from the PCB Artist program. There are no errors are. The signs number off details are different !!!

[scs]

I noticed error a transistor VT9 is connected back. Please for excuse.

[ivconic]

Much nicer and easier to follow drawing.

Yes, there is much of the design that could have been upgraded. Any small processor easily does all the timing and allows easy experimentation and even several modes in the field.

VCO output is a must if having low/high conductor discrimination. There can be a lot of audio information this way.
Lots of simple methods for VCO.
A meter is handy to check strength of signal, target size/depth. I added a meter to my HH2 and is handy at times.

Use of Atmega and LCD will allow tossing 40-60% of present schematic out.
But first it would be good to make it as it is and see the behavior.
Later on, step by step to replace some parts with code in Atmega.
I might do that when i nick some spare time. Will see.

[waltr]

Always hate to see such awkward way of drawing schematics.
Purposely messed up to the level of being completely confusing.
Also kind a looking more "profound" than actually it is.
Now, once you put it on "paper" on right way; everything evolves nicely.
...
As for the design; it's alright. Simple enough and yet offering some features which other simple pi designs are lacking.
It is a step forward comparing to other simple PI designs available on this forum. Not just "another pi...".
I hate to see the analog meter scale there.
Was it so hard that voltage to fed to thrs. input of cmos vco and get two-tone behavior?
7555s are cheap, why not using even two vco's? And get two nice trimmed and pleasant tones.
Just an idea.
Timings... 4538, also hate to see them too. Atmega can replace them with no sweat at all.
Etc etc...
Things can be lifted on much higher lever here.
It is good starting point though.
I had enough "fun" time to redraw schematic as i like to see it.
[ATTACH]46083[/ATTACH]

Much nicer and easier to follow drawing.

Yes, there is much of the design that could have been upgraded. Any small processor easily does all the timing and allows easy experimentation and even several modes in the field.

VCO output is a must if having low/high conductor discrimination. There can be a lot of audio information this way.
Lots of simple methods for VCO.
A meter is handy to check strength of signal, target size/depth. I added a meter to my HH2 and is handy at times.

[ivconic]

Of course; looking at such terrifically awkward drawings: you can generate only more mistakes in redraw.
So i spotted one i made at ps part.
Here is corrected:

[6666]

lf357 is obsolet, why did all engineers here continue drawing design with lf357
i got a handful of fake lf357 from ali, just for testing - but they are crap

I got a bunch of fakes to

[6666]

Thanks Ivconic , very quick drawing

[ivconic]

Always hate to see such awkward way of drawing schematics.
Purposely messed up to the level of being completely confusing.
Also kind a looking more "profound" than actually it is.
Now, once you put it on "paper" on right way; everything evolves nicely.
...
As for the design; it's alright. Simple enough and yet offering some features which other simple pi designs are lacking.
It is a step forward comparing to other simple PI designs available on this forum. Not just "another pi...".
I hate to see the analog meter scale there.
Was it so hard that voltage to fed to thrs. input of cmos vco and get two-tone behavior?
7555s are cheap, why not using even two vco's? And get two nice trimmed and pleasant tones.
Just an idea.
Timings... 4538, also hate to see them too. Atmega can replace them with no sweat at all.
Etc etc...
Things can be lifted on much higher lever here.
It is good starting point though.
I had enough "fun" time to redraw schematic as i like to see it.

[Andi68]

http://www.allxref.com/search.htm?part=LF357

http://e2e.ti.com/support/amplifiers/f/14/t/84056#