Tesoro Eldorado on the bench

[paku]

https://youtu.be/fIdnMSwfVNc?si=pAWRKnu4BFsS4Aem

[paku]

Tested Video Working Tesoro Eldorado By Ivconic
Thanks To Ivconic

Old Video ReUpload

[Sean_Goddard]

If anyone ever decides to respray a "chocolate" Tesoro, the best match I have found is Mercedes "Erdbrun" (Earth brown).

[Maurizio2]

Download expanded library here, it has diode 1N749

http://ltwiki.org/files/LargeCollection.zip

Great!

[dbanner]

Download expanded library here, it has diode 1N749

http://ltwiki.org/files/LargeCollection.zip

[Maurizio2]

You can add some capacitance in parallel with R26 to delay the RX signal. At 10kHz, 58pF will give 20°.

Hi Carl!
Thank you.

This is a good work-around but I don't know if it is possible to calculate capacitance from degree...
However, also this solution is very interesting.

[Maurizio2]

Maybe this can help

Hi Dbanner!
Thank you, very much.
Please can you add also the 1N749 zener diode library? Because I get this error:

[Carl-NC]

However, from what I see there are no phase differences between TX and RX while in reality in Eldorado RX must be delayed by 20° compared to TX.
Does anyone know how to introduce this delay in LTspice?

You can add some capacitance in parallel with R26 to delay the RX signal. At 10kHz, 58pF will give 20°.

[dbanner]

Maybe this can help

[Maurizio2]

Dear friends,
I took the EldoradoQT file again to do some simulations.
The first problem I had is that the potentiometer is missing in the standard LTspice library. So I replaced it with two resistors, setting one to the value of one ohm close to zero (R1) and the other (R21) to the maximum value of the potentiometer, alternating them in order to see in the simulation what happens at the minimum and maximum.
The second problem is that the zener 1N749 is missing in the library so I replaced it with a 1N750 which has the closest value.
Finally the third problem concerned the TIS75 FETs which are not there and I replaced them with 2N4393s.
To have everything visible on a single scale I put: K1 Ltx Lrx 6.3e-3 instead of 6.3e-5 (See Target Coupling in Image1).

However, from what I see there are no phase differences between TX and RX while in reality in Eldorado RX must be delayed by 20° compared to TX.
Does anyone know how to introduce this delay in LTspice?
See Image2.

With normal non-mineralized soil like where I come from, the GB is set more or less in the middle. By adjusting the GB to 50% (R9 = 50Kohm) I saw that the discrimination at idle is delayed compared to the GB by about 120° (Image3). While at most it touches 180° (Image 4 and Image5).

Can anyone tell me if I'm doing it wrong and if so, where?

[enjoykin4]

Tesoro Eldorado Super MOD by Игорь Барановский !!

Tesoro Eldorado Super MOD by Игорь Барановский !! Two Eldorados built and ready for gold prospecting All info search here:Металлоискатель "Tesoro Eldorado"http://vk.com/topic-33752123_28990794?offset=3200#/topic-33752123_28990794?offset=5840Regards !!enjoykin4

[Sacchetti]

dot forget make video

Ok but it is normal, about 28cm for every coin in air. Some coin a bit more.

I expected more and searched a way to get 40cm but without obtain this objective.
I am disappointed, a little frustrated.

[Sacchetti]

Hi,
I have solved the problem changing the coil.

However, Eldorado sometime produce a little sound in absence of target.
I have seen many video about TGSL that make the same.
I do not understand why and I did not found a way to eliminate this problem.
Do you have a proposition to solve it?

About the one I have built I am not satisfied at 50%.
The discrimination is enough for me but the main problem is how to get a better and clear sound when a little target is at 28cm or more.
I have seen some video of TGSL/IGSL with a perfect sound.
They are not the standard schematic but they was modified.
These modifications was already proposed from other users? Can I found them in some threads?
Sorry, it is impossible to read the entire forum, it take about one year.

I have tried to do some modifications to increase depth, after the simulation with LTspice.
The simulation are good but after in practice I did not get the result searched.
I have tryed to increase sensibility but without success. Nothing is changed.
These modifications was already proposed from other users? Can I found them in some threads?

I have read all the thread relative to "Tuning and troubleshooting of TGSL" and I have found in it many informations to tune the GB/DISC section.
Between TGSL and Eldo change frequency and other details but the schematic are very similar.
I found it a very nice thread.

I am going to sleep, sorry see you tomorrow.

[Sacchetti]

I am trying to connect the coil to the circuit in a different way.
Stay tuned, I will inform you about what I get as result.

I have done many tests and checks but I do not found a way to solve the problem at the moment.
Moving the cable or touching the coil the MD sound.

Can be it is necessary to change the cable but it is not possible to do without damage the coil.

Looking the original tessoro manual I found this coil to be used in the photos.
Therefore this coil must work well with Eldo.
I do not understand where is the problem.

One way to solve it can be is to check the original PCB and look as are connected potenziometers, coil connector and all the rest.
Can be there are big differences between the original and the clone.
I am going to continue following this way but I can not remove my perplexity about the cable!

Tips?

[Sacchetti]

Another information:
I have already read this thread: http://www.geotech1.com/forums/showt...l+moving+cable
But I have a problem using an original tessoro coil.
Please, help me. Thanks to all.

I am trying to connect the coil to the circuit in a different way.
Stay tuned, I will inform you about what I get as result.