LOOKING FOR GOLDSCAN 4 Schematic.

[Jose]

JOSE
could you please tell me the width of your TX pulse and how many PPS, thanks.

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

[6666]

JOSE
could you please tell me the width of your TX pulse and how many PPS, thanks.

[mschmahl]

Here is an other one complete 1. pcb and complete 2. pcb. It is not my Goldscan. These pictures I have collected from internet. I have a lot more of pictures, schematics... from Goldscan.

[mschmahl]

You can use this schematic. It is very good. I have also a lot of pictures and can make more.

[Old cart]

I have the original goldscan 4, so we have something to compare. It is without the original coil and the original battery and maybe with some otherwise set internal trimmers, but it is better then nothing. The used coil is from my Mirage and a regulatet LiPo-accu (24V regulated to 15V) is now used as power supply. I also have a o-scope.
I´m interested to build it as a compact design machine (all in one box, the original Goldscan has 3 boxes) for inland search on not so easy ground/fields. This ground have slag and mineralic stones in it.

A good place to start is with very high quality photos showing both sides of the PCB. Do you have the ability to take these? I find you do not need a super fancy camera but just strong light that is very even. Compact cameras and even the newer iPhones can take very good pics under the right light.

I also prefer a compact design, maybe a small control box with a separate battery box mounted under the arm cuff. Getting the center of gravity near the elbow is the key to getting an easy to swing detector ( low polar moment of inertia ).

The detector could be made modular maybe with separate transmitter/power supply, receiver/timing, and possibly processing sections.
This would allow an "exploded" layout on the bench for easier development as well as a compact design for field use.

[mschmahl]

I have the original goldscan 4, so we have something to compare. It is without the original coil and the original battery and maybe with some otherwise set internal trimmers, but it is better then nothing. The used coil is from my Mirage and a regulatet LiPo-accu (24V regulated to 15V) is now used as power supply. I also have a o-scope.
I´m interested to build it as a compact design machine (all in one box, the original Goldscan has 3 boxes) for inland search on not so easy ground/fields. This ground have slag and mineralic stones in it.

[Old cart]

I am very excited about this possibility. Without making this a huge detailed project maybe a quick response by those who are interested and what they could add to the project is appropriate.

I can add schematic evaluation, PCB evaluation, project performance testing, documentation, and maybe some project coordination to the list.

[greylourie]

Yes, Reg offered a blueprint for simplifying the original. And Jose, too, made good contributions. There is potential for a great learning tool on basic ground balancing, and target separation by Tau or "conductivity".

[Old cart]

I might add that the inclusion of many test points would make the design more versatile. While I can not do a professional job of laying out a PCB I can help with the legwork of preparing the design for a build. I do agreed Minipulse could be modified to add GB and maybe that is the shorter path since it is already well documented.
I want the detector for beach hunting so am just looking for DISC, do not really need GB but that is the same circuit.

[Old cart]

I am looking for a completely cleaned up circuit with all the mods, but most importantly a well designed PCB. It seems that if we could get a stable design ( and we are close)'that production PCBs could be made cheaply and a group buy done for parts. I am willing to help with a build document to enhance the building experience.

[mschmahl]

For me a Goldscan-clone with more modern parts and without the most of trimmers would be a good solution. Reg had a lot of ideas to make the building simpler. It could be in SMD, so you could use realy good parts. I have no problem with that.
The other idea is to use a good concept e.g. Minipulse or Hammerhead and build in the GB circuit of the Goldscan.

[greylourie]

Maybe Ivconic has the relevant schematic related to those two pdf's. I just wonder what the majority of members here want ? A Goldscan that coincidentally has ground balance, or a P.I with ground balance using the principles found in the Goldscan ?

Alexismex posted the first back engineered circuit. Very few errors or omissions. And those have been pointed out in posts on the forum. Offhand, there was the missing connections to GND on two J113 fets, allied with the two SAT caps. And with help from mschmahl, the presence of a 1nf cap in the feedback circuit that contains two diodes on IC3 was clarified. Theres a lot of useful posts scattered all over.

You could easily take the Hammerhead and add the logic/gating. Jose posted very good graphics showing the timings, simply scale to suit your PPS. And have ground balance. Add the circuits/switches Reg and Jose posted, and have selectable High/Low conductor signals. Now you have a very versatile detector.

It was pointed out to me that Orbit used part of the Surf P.I in his "GS6" creation. So you can see, to apply the GB principles can work and be applied.

[Old cart]

Aquí encontré otra PCB en el foro, yo no hice este esquema, no se si es correcto. [ATTACH] 30709 [/ attach] [attach] 30710 [/ attach]

Has anyone built or investigated this PCB? Looks very well done based on superficial examination.

[greylourie]

Yes, its interesting. Also a battery meter there. The target strength indication is also found on modern P.I. I like the led array on the Garrett ATX P.I. I sometimes think, if Eric Foster was born in a different time and used micro controllers, maybe his Goldscan detectors might look quite similar in feature set to the Garrett. Its almost like a montage or a modern version or tribute in some small ways. Non-motion mode (especially the audio response) and the Retune button.

[Old cart]

Like the depth scale right on the detector shaft.