Tesoro Eldorado

[Max]

maybe there's an erro on schematics

So you are saying my pcb has no mistakes? Right?
Thank you very much Nakky! You saved me waiting day or two and recheck myself again...
Best regards!

P.S.
Wirements are simplier than on TGS. Draw on schematic pretty logically.
Maybe there is mistake? I rechecked those several times, yesterday.
I obeyed schematic completely. Still confused?

Hi,
this configuration is similar to BandidoII's one: look picture below.

You the 47K resistor instead of 220K and there's no capacitor of 10nF there... but the rest is about the same stuff.

BUT look carefully... you'll see a permanent connection of all-metal channel to output part that is missed in that eldorado schematic...

I think the 47K resistor was connected different way... from output of all-metal channel to the output amplifier (instead of the 200K of bandidoII version) and capacitor is missed in eldorado... maybe to have faster response... then could be in the two ways below.

First is how I think it was... second (mod2) is how you can test too... to make it similar to bandidoII ...just lower the 47K to 1K there.

Try the first mod and let me know how it works.

Best regards,
Max

[nakky]

Hi Ivconic,we were busy at the same time with the ELDORADO.Grt Nakky.

[nakky]

Hi Ivconic, Sorry, change your pcb a little,not checked yet.Grt Nakky.

[FOMA]

Here is so beside I well work.

[FOMA]

change by red colour

[FOMA]

Elidoado I have did here is so.

[aft_72005]

Hi FOMA
Also I interest to know about your experience with eldorado.
How distance can detect coin with 2cm diameter in air ?
Regards.

[FOMA]

Hi aft 72005.
Horakteristiki my ELDORADO are befitted this data

[aft_72005]

Hi FOMA
Thank you.
Regards.

[ivconic]

Problem solved, Eldorado is working. I made trivial mistake reversing FET's. Primary i designed pcb for BF245's and later used J107's...
I checked everything again and again...damn! Finally today i spoted this stupid mistake!
So pcb is accurate! No mistakes. Schematic also, except few details, 15pf must be instead 150pf and 100k instead 10k like Foma posted. I would like to add that 100pf on pin 8. of LM308 will close external compensation and LM308 will work less erratically, almost calm 100%. So i predicted it on pcb and retreived it on its place. It is working fine.
I used TGS coil with Eldorado and have feeling it is not the best solution. It is working descent but not that good as TGS. 1 Euro coin detecting bairly at 15-18cm.Silver fork at 25-28cm, iron piece 4x4cm at 35cm in All Metal mode.
I noticed really good discrimination, maybe a bit better than on TGS.
Al Metal mode is very interesting here, full no motion feature! I like it! Other hand, Disc mode is not full no motion, yet bit better (wider) audio than on TGS. If i can only achieve same depths on coins as with TGS..
I think TGS coil can serve here only in testing purposes, for real performances original Eldorado coil must be made separatelly.
So...c'mon again here; let's conclude few important facts:
-Real original Eldorado frequency,
-Any possible Eldorado coil datas,
-To choose between better design: DD coil or concentric coil?

So far i made only DD coils for tesoro, actually never tried any of c.c. coil.
I guess it is time to try to make some proper c.c. coil ....

[ivconic]

Oh yes...i used brand new TL062's (just got those) instead LF442 (couldnt obtain those). I think those are good substitutions so no need to look for LF442 at all. TL062 works very good in many different designs...

[FOMA]

The Capacitors 0,047 and 0,033 such as beside BANDIDO.
Consequently worker frequency as beside BANDIDO is equal 10 kHz.
My ELDORADO has a frequency 10,5kHz. The Spool CONCENTRIC.

The Amount whorl is specified aproximately.

[ivconic]

Thanks Foma!
Can you make my life even more easier and tell me have you tried this coil?
What is wire gauge here?
Last, you can tell me air distances for 1e coin and simillar.
I do have now wires 0.3mm and 0.25mm available at the moment.
Yes, 20cm diameter search head is more interesting for me than any larger.
I do prefer small diamm. search coils due many reasons.
Regards!

[FOMA]

HI IVCONIC.

I have done such spool.I used the wire 0.25mm..
I have not 1 EURO. I have a coin 10 Eurocent.
Sensitivity in mode DISK.=25cm.
Sensitivity in mode ALL MET (AUTOTONE)=30cm.
All measurements conducted in apartment. Here much hindrances and if use the mode ALL MET without mode AUTOTONE, that detector is agitated. And aloud sounds.
Spool CONCENTRIC possible to do and so:

http://thunting.com/geotech/forums/s...oto=nextnewest

[ivconic]

Thanks Foma!