Pulse power Goldscan IV

[dbanner]

Original PCB layout.

[kt315]

thanks DB. can you share also the JPG's that used like the layers. this is a copy from something either from original board or DIY project of somebody.
would like to look on those used pics.

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Schematic diagram.
Resistors R49 and R50 are not on original PCB.
A small change to schematic for piezo(LS1) connection to R80 and C52 was made to match PCB(audio and PS board) layout.

[dbanner]

......." this is a copy from something either from original board or DIY project of somebody."

This is my work. Reverse engineer from photos. It matches perfect with schematic.

Here are images used.

[kt315]

nice Home Work DB. did you order the pcbs?

[dbanner]

nice Home Work DB. did you order the pcb?

No. It is only for Mr.Foster leaving us which inspired me to draw pcb

[kt315]

do you have a contact with his wife?

[dbanner]

No.

[Jose]

Great job Dbanner, thanks for sharing.

[dbanner]

Great job Dbanner, thanks for sharing.

Jose, can you recall what modifications you made? The power supply? Two stage preamp?

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Some pics

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Some more pics

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Some info

[Jose]

Jose, can you recall what modifications you made? The power supply? Two stage preamp?

I did a lot of mods on the GS4, mainly because I like to experiment.I replaced the preamplifier with a two-stage one for a faster response, the HH2 schematic was copied.
The source was modified, a 7660 was adapted to improve the noise problems it had at the time. Today we know that the noise problem was the PCB layout you were using, and not the original font layout.
Another modification was the resistor 51 of 220K, it was replaced by 22K.
The Papa Alex scheme is the most accurate, the GB control is 10K. and not 50K, as it appears in the previous scheme.
I don't remember other errors in the schematic except those already known as the connection to GND of the FET113. and the addition of the 470K resistors, as mentioned in Reg's writings.
The selector could be replaced by a reversing key with a midpoint, Reg explains in his writings, there is a scheme proposed by him in the forum, I will search for it and post the link.
There are many ideas that can be tried in this scheme that I will comment on later, I do not want to create confusion.
I would not worry about modifying the source, having the original design PCB, we should not have noise problems, if it is installed in separate boxes it would be better, at most it would be shielded.

[dbanner]

I did a lot of mods on the GS4, mainly because I like to experiment.I replaced the preamplifier with a two-stage one for a faster response, the HH2 schematic was copied.
The source was modified, a 7660 was adapted to improve the noise problems it had at the time. Today we know that the noise problem was the PCB layout you were using, and not the original font layout.
Another modification was the resistor 51 of 220K, it was replaced by 22K.
The Papa Alex scheme is the most accurate, the GB control is 10K. and not 50K, as it appears in the previous scheme.
I don't remember other errors in the schematic except those already known as the connection to GND of the FET113. and the addition of the 470K resistors, as mentioned in Reg's writings.
The selector could be replaced by a reversing key with a midpoint, Reg explains in his writings, there is a scheme proposed by him in the forum, I will search for it and post the link.
There are many ideas that can be tried in this scheme that I will comment on later, I do not want to create confusion.
I would not worry about modifying the source, having the original design PCB, we should not have noise problems, if it is installed in separate boxes it would be better, at most it would be shielded.

Thanks for these insightful remarks.
I think it's possible to modify the pcb layout to make a few changes to the circuit, such as a two stage preamp and some other tweaks, etc.
The consensus in the past seemed to be that the goldscan IV was a bit unstable. But also has good basis of becoming an excellent machine.