LOOKING FOR GOLDSCAN 4 Schematic.

[ivconic]

Last thing I done (was lazy to record another video) is to make 25cm coil, 0.3mH / 0.9R.
In All Metal mode with GEB slightly lose; it improved air "depths" to ~15cm on small Roman coin as well as on gold coin.
Not good enough.
Some other works in progress...

[eduardo1979]

Last thing I done (was lazy to record another video) is to make 25cm coil, 0.3mH / 0.9R.
In All Metal mode with GEB slightly lose; it improved air "depths" to ~15cm on small Roman coin as well as on gold coin.
Not good enough.
Some other works in progress...

Why don't you make the GS-5?
In my opinion it is a better detector than the GS-4.
In the past I made a LITE version of GS-5 and it worked very well.
My LITE version has the identical time base as TDI SL.
The VCO is very nice, because it has a CD4046.

https://youtube.com/shorts/2tXTbySBUD4

[ivconic]

It works really nice. But I'm interested in core performance.
Do you still have that detector?
To show how GEB works on it.
And when you set the GEB to some "mineralization", after that you can test and record how it detects a Roman coin or a small gold coin.
In "Off" mode (GEB off) my GS4 also has "enormous" depths in the air on all tested targets.
If you still have that detector; I would be grateful if you could record minute two of the mentioned test.

[ZOUjiarui]

Why don't you make the GS-5?
In my opinion it is a better detector than the GS-4.
In the past I made a LITE version of GS-5 and it worked very well.
My LITE version has the identical time base as TDI SL.
The VCO is very nice, because it has a CD4046.

https://youtube.com/shorts/2tXTbySBUD4

The schematic is damaged, please send it separately.

[eduardo1979]

It works really nice. But I'm interested in core performance.
Do you still have that detector?
To show how GEB works on it.
And when you set the GEB to some "mineralization", after that you can test and record how it detects a Roman coin or a small gold coin.
In "Off" mode (GEB off) my GS4 also has "enormous" depths in the air on all tested targets.
If you still have that detector; I would be grateful if you could record minute two of the mentioned test.

I no longer have this specific detector.
I have something very similar, the only thing is that the timing of the samples is done digitally with an ESP32 processor.
My tests in the video are done with the GEB activated and rejecting a hot rock. When activating and deactivating the GEB channel there is practically no difference in depth. The difference is minimal. In the past I built in GS-4 and I didn't like it because of the loss of depth with GEB mode activated. GS-5 with the 33cm MONO coil, in GEB mode activated and rejecting a hot rock, detected a gold wedding ring 33cm in the air.

[ArchibaldSTM]

Everything opens fine for me... I don’t use the schematic file

[ivconic]

I no longer have this specific detector.
I have something very similar, the only thing is that the timing of the samples is done digitally with an ESP32 processor.
My tests in the video are done with the GEB activated and rejecting a hot rock. When activating and deactivating the GEB channel there is practically no difference in depth. The difference is minimal. In the past I built in GS-4 and I didn't like it because of the loss of depth with GEB mode activated. GS-5 with the 33cm MONO coil, in GEB mode activated and rejecting a hot rock, detected a gold wedding ring 33cm in the air.

What do you think is the essential difference between the GS4 and your GS5 regarding the problem of loss of depth in GEB mode with the GS4?
I assume the schematic and pcb you posted is 100% correct?

[eduardo1979]

What do you think is the essential difference between the GS4 and your GS5 regarding the problem of loss of depth in GEB mode with the GS4?
I assume the schematic and pcb you posted is 100% correct?

The schematic and PCB are correct. I don't like posting things that don't work. The main difference between the GS4 and GS5 is the GEB circuit. They are two totally different forms. The GS5 has the GEB the same as the TDI.

[ivconic]

Thanks!
Coil on video is "DD" or mono coil?

[eduardo1979]

Thanks!
Coil on video is "DD" or mono coil?

Mono coil, 13".

[eduardo1979]

All JFET transistors can be replaced with a CD4066. In my new detector I removed the J113 and put CD4066 in their place. I make a small parenthesis...J112 do not work well, J113 are the ones that work correctly. I say all this because I tried it at the time.

[pito]

sum ;
-5 + 5 = 0, = decreased sensitivity = your case
absolute value;
|-5| + |5| = 10 increased sensitivity = easy to implement with attiny85 or arduino

[kadir6141]

Probably a resistor.
I assume it is R52 (22k) GND resistor.

mr ivconic
It's not a 22k resistor. It looks like another resistor.

[ivconic]

All JFET transistors can be replaced with a CD4066. In my new detector I removed the J113 and put CD4066 in their place. I make a small parenthesis...J112 do not work well, J113 are the ones that work correctly. I say all this because I tried it at the time.

I'm really "lucky", because I put J112, I couldn't find J113.
Of course, that's not the complete reason, but it's certainly one of the reasons why my DIY doesn't have some "depth".

[eduardo1979]

I'm really "lucky", because I put J112, I couldn't find J113.
Of course, that's not the complete reason, but it's certainly one of the reasons why my DIY doesn't have some "depth".

You could try to make a modification, replacing the J112 with a CD4066. The bad thing about all that is that you have to do it with cables and that is not good, because the cables generate noise and right there the noise is of no interest.