LOOKING FOR GOLDSCAN 4 Schematic.

[mschmahl]

Hello Mschmahl
This is how I adjust RV6, please correct me if I'm wrong.
Hold or make adjustments bridge during the key "Reset".
Place SW1 in position 2 "All Metall" (RV6 is canceled).
Adjust RV5 to 0 volts, leg 7, U13: B.
Adjust RV7 to 0 volts, leg 8, U13: C.
Place SW1 in position 1 or 3 (RV6 is enabled).
Adjust RV6 to 0 volts, leg 8, U13: C.
Jose

Hello Jose and all,

Deep is now good, but i can´t eliminate iron.

Must it be leg 1 of u13 to adjust RV5 to 0 V instead of leg 7?

How had you adjust RV1, RV3 and RV 4?
I have adjust RV1 leg 7 u12 to 0 volt, RV3 leg 1 u12 to 0 volt and RV4 leg 10 u12 to -7mVolt.
Which position have SW1(always 2 "All Metall") to adjust RV1-RV8?

Here is a Scopeshot of first sample.
bottom-line is Output of NE5534
upper-line is U5 pin6/11

First picture 5V/15uS
Second picture 5V/5uS

[Jose]

Hello all,

I have managed the problem with my coil, now i use the dual-military-coil from schiebel (AN/PSS-12) with TX coil 236 uH 0,9 R and RX coil 447 uH 2,6 R.

I have a problem with adjust RV6. Have i adjust it to zero and must Pin 10 of U13 be zero?

Hello Mschmahl
This is how I adjust RV6, please correct me if I'm wrong.
Hold or make adjustments bridge during the key "Reset".
Place SW1 in position 2 "All Metall" (RV6 is canceled).
Adjust RV5 to 0 volts, leg 7, U13: B.
Adjust RV7 to 0 volts, leg 8, U13: C.
Place SW1 in position 1 or 3 (RV6 is enabled).
Adjust RV6 to 0 volts, leg 8, U13: C.
Jose

[mschmahl]

Adjust gs4

Good work MSCH, Now you must adjust( the damping coil first) well all the stage because 1 Euro is for 20 cm at least... and with your another coil (400uH) you still had the same result because GS4 is not adjusted...

Hello all,

I have managed the problem with my coil, now i use the dual-military-coil from schiebel (AN/PSS-12) with TX coil 236 uH 0,9 R and RX coil 447 uH 2,6 R.

I have a problem with adjust RV6. Have i adjust it to zero and must Pin 10 of U13 be zero?

[Jose]

Hello to All
I built the GS4, the PCB used is different from what we see here, is one face that I found on another forum.
At first it was very unstable and impossible to adjust, the cause was the noise.
This noise had two origins. One is the PCB, perhaps because of poor design, and the other originated in the source of 5 volts, corresponding to the circuits 555 and associated components.
I replaced the 555 by 7660, the scheme copied from HH1, and the noise decreased considerably.
Make bridges on the PCB, which corresponds to GND, and make a shield to 5534.
It's working well, is very sensitive, and fully rejects iron. Be careful with discrimination, which can reject bronze coins larger.
There are different circuits GS4 in the forum, with different values of some components.
What worked for me are:
R49 and R50 are 470K.
Potentiometer 10K GND must be
Apparently lack a capacitor between the legs 6 and 7, U13: C, as shown in the original photos posted in the forum.
I put nf 220.
Hope this helps.
A Warm Welcome
Jose

[maikl]

means:
i´m happy to see another working detector from forum member in germany
lean back now and drink a beer and i dance towards my lcd screen

if i have time next weeks i will follow you good work until here
sure you can improve it

regards bernd

Can you get a link to the German forum?

[mschmahl]

I hope it will be good for german fields. there are a lot of iron junk. and the gs4 can differentiate between iron and and other metals. Mineralisation isn´t a big problem there.

I´m very busy, so i make the changes at the weekend.

[satdaveuk]

Hi all
I been reading through the 4 pages of this thread, am I right on the understanding that this machine is only good for beach detecting like so many other PI detectors.
Im in know rush to build this one yet because still working on my minipulse 3.
I have read from a couple of uk detectorists that Garrys PI design handles minerals quite well on open land, dont know how far its true but worth the build just to see because its quite stright forward by the looks of the circuit, anyone here built one?

All the best boys and girls

[mschmahl]

Good work MSCH, Now you must adjust( the damping coil first) well all the stage because 1 Euro is for 20 cm at least... and with your another coil (400uH) you still had the same result because GS4 is not adjusted...

Thanks for the hint Alexismex. I had it adjust all but not with damping first. Thanks.

[Alexismex]

Good work MSCH, Now you must adjust( the damping coil first) well all the stage because 1 Euro is for 20 cm at least... and with your another coil (400uH) you still had the same result because GS4 is not adjusted...

[bernte_one]

means:
i´m happy to see another working detector from forum member in germany
lean back now and drink a beer and i dance towards my lcd screen

if i have time next weeks i will follow you good work until here
sure you can improve it

regards bernd

[mschmahl]

Now the Goldscan is working.
The deep is not so good (only 10 cm for 1 Euro) but the test-coil only have 350 uH and 1,4 Ohm.
Next step is to build a coil with 400uH and 3 Ohm or change PCB for a dualcoil.

[mschmahl]

my first goldscan 4

I´m building my first Goldscan 4. I got a PCB from bernte_one. I want to build it with ideas from reg (high conducters, low conducters; without RV 1, RV 3, RV 5, RV 6 and RV 7; OPA 4277; other switches); with the power-circuit from porkluvr; and the Schematic from Alex.

[satdaveuk]

hello

must search my archieve for bw image.
maybe next days.

regards bernd

I got it now thanks together with the circuit and placment ive posted it here on main page with the permission of the person I equired it from.

Regards

[satdaveuk]

hello

must search my archieve for bw image.
maybe next days.

regards bernd

Thanks Bernd
Your a gent

[bernte_one]

hello

must search my archieve for bw image.
maybe next days.

regards bernd