LOOKING FOR GOLDSCAN 4 Schematic.

[mschmahl]

Because it is not necessary to destroy the Goldscan. The above schematic is good and we can use it as base.
Another reason is that we have no more opportunities for comparison.

Now we have to change some parts and reduce the components, so it can be a nice, simple PI with GB.

I would leave out the probe and the meters (amperemeter and voltmeter). Then we have to look to the ideas of reg to change some components to more precise one, so we can left out some intern trimmers.

[Old cart]

KT315 be nice! I asked for those pictures because I had not seen them before. We are all trying to accomplish the same thing here. Everyone does what they can.

[samii]

same more photos
http://www.geotech1.com/forums/showt...light=goldscan

[Orbit]

https://www.youtube.com/watch?v=dV-3...ature=youtu.be

[mschmahl]

Great!
Is this your goldscan Orbit?
Do you have some information how is the 2-tone built in?

[Orbit]

Yes this is my gs 4 Detector .

[mschmahl]

can you write something about the dual tones? How have you done it?

[Jose]

Hi Ranko
Here is the pulse sequence of the GS4.
Alexismex's schema is correct.

[Jose]

Hi Ranko
Set U12 as shown in the diagram.
In normal operation, the voltage at pin 8 of U12 must be 4.2 Volts negative.
Set to 0 volts, pin 7.
Set to a few negative millivolts on pin 10. Until you get around 4.2 Volts negative on pin 8.
The marked resistance of 220k. I use 22K.
Use BF245 A, B or C.
J113; J112.
Other JFETs may not work in this scheme.
Jose

[6666]

Hi Ranko
Here is the pulse sequence of the GS4.
Alexismex's schema is correct.[ATTACH]40177[/ATTACH]

Thanks

[eclipse]

Jose thanks for the Secuencia de Tiempos file.
Really useful for any builder should attempt to build it to have the correct timing diagram.

[ricalbertvig]

hello I see an error in the position of j113 --- of pcb..1: D 2: S 3: G .. that is the order of the pins because pcb is placed in a way difirecte to the scheme?

[ricalbertvig]

hello ... I have doubts on how to connect j133 .. the Q8 and Q6 .. in some pcb appears pin 2 (s) from j113 to U10 PIN 5 and to 3 ... in other pcb appears differently, pin 1 (d) connected to pin 5 and 3 ... could someone help me? .. what would be the correct way to connect q6y q8 .. help please

[Jose]

The "S" terminal connects to GND.

[ricalbertvig]

hello jose thank you very much for your answer ... I mean I understand j113 pin s is connected to pin 5 and 3 of u10 ... and grounded through c25 and c26 ..