LOOKING FOR GOLDSCAN 4 Schematic.

[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.

[6666]

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

Thanks

[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

[Jose]

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

[mschmahl]

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

[Orbit]

Yes this is my gs 4 Detector .

[mschmahl]

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

[Orbit]

https://www.youtube.com/watch?v=dV-3yKez6YY&feature=youtu.be

[samii]

same more photos

http://www.geotech1.com/forums/showthread.php?17372-Goldscan-IV-4-position-switch-question/page2&highlight=goldscan

[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.

[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.

[kt315]

I have the original goldscan 4, .

why are you not able to desolder pcb and give full clear pics for all? why you put pics what were putted before again? no need put same pics again and again. do YOUR job, YOUR Home Work, at first, and project will move. another way it is only
regular verbiage and nothing.

[mschmahl]

MSCH Thanks for all this pictures and schematics. do you have nay pictures of the back side of the circuit boards?

Here they are. It´s the same on my PCB, but the pictures are from alex. The smaller one is from the power/audio PCB.

[6666]

I do not know exactly the pulse width TX, because I have installed a preset, for optimal fit between power consumption and performance.
I adjusted in 150 microseconds for TX.
I think in the original scheme is 200 microseconds or a little more.
The frequency is adjustable between 450 and 550 Hz.
Jose

Thanks Jose

[Old cart]

MSCH Thanks for all this pictures and schematics. do you have nay pictures of the back side of the circuit boards?