Tesoro Lobo news

[UFO]

Looks good man. I think you will enjoy the Lobo.

[Legaucho]

Hello all

Connections on rear plate now..

[maxbiri]

Very very nice!!!!!
Good work
In my lobo design i found lot of problems with coil, do you plan use a original coil?

Bye Max

[homefire]

Ground Bal would be Most important here in NM.

I need mine on the front panel for sure.

Your getting it going good there.

[Legaucho]

Very very nice!!!!!
Good work
In my lobo design i found lot of problems with coil, do you plan use a original coil?

Bye Max

I will used one TESORO 9'' X 8''

[Legaucho]

Hello all

Before the last step, all connections ready now.

[homefire]

WOW! lOOkING gOOd there.

Coming along nice for sure.

[bernte_one]

i will see this machine work

[homefire]

I will used one TESORO 9'' X 8''

Is that a 20Khz coil?

[Legaucho]

Is that a 20Khz coil?

Hello

The caracteristics of the Tesoro 9'x 8' concentric coil:

RX = 6.54mH ( 24.9 Ohms )
TX = 6.03mH ( 26.1 Ohms )

Good news, my first try was not not so bad, no mistakes on PCB and all function is running, I must finalize the discrimination, I am currently on :

RX stage one 4.7nF capacitor and on TX stage one 15nF capacitor. Can someone help me refine these parameters to obtain the initial 20 kHz of the detector.

[bernte_one]

hello

the last coil i buy was for cibola, vaquero, lobo supertraq
combination of 1mH and 16mH
are you sure you have the right coil?

you can caculate frequency
when you now inductivity and caps for the coils

regards

[Legaucho]

Hello bernte,

I have mesuring those caracteristics on my coil ( it's a first generation coil ).

[Legaucho]

Hello bernte, again me

I have also two other coil, I can try it

One DD homemade coil

RX = 11.14mH ( 51.9 Ohms )
TX = 1.68mH ( 9.5 Ohms )

One DD Fisher coil

RX = 7mH ( 38 Ohms )
TX = 0.67mH ( 2.4 Ohms )

[porkluvr]

Legaucho, what do you have in the way of test equipment?

You need to choose between either using the factory coil which was designed for a different machine, or the home made coil which may or may not be properly aligned. And we need to know what you have in the way of test equipment before you will get any good advice.
Just my opinion.

The Fisher coil probably has the wrong connector so shouldn't you forget about that, at least for now?

It is relatively easy to figure out how to find a capacitor to tune a TX coil to a particular frequency, but it will be much more difficult to align the receiver phase to the correct angle for your ground and discrimination channels to work correctly. I really hope you have a dual trace oscilloscope.

edit: For the 6.03mH tx coil you should use a .01uF capacitor and about 600pF in parallel to tune to 20kHz. If you can, select a .01 that is slightly high and then you won't need a parallel capacitor.

edit: With the 6.54mH rx coil I think you should use a 3nF capacitor in parallel. That should give you approximately the same phase as what a 10mH coil (with no parallel capacitor) would.

[Qiaozhi]

Hello

The caracteristics of the Tesoro 9'x 8' concentric coil:

RX = 6.54mH ( 24.9 Ohms )
TX = 6.03mH ( 26.1 Ohms )

Good news, my first try was not not so bad, no mistakes on PCB and all function is running, I must finalize the discrimination, I am currently on :

RX stage one 4.7nF capacitor and on TX stage one 15nF capacitor. Can someone help me refine these parameters to obtain the initial 20 kHz of the detector.

First change the 15nF on the TX to 10nF. This will give you 20.5kHz. which should be close enough. As a "calculated guess", I would also replace the 4n7 cap on the RX with a 10nF. If the residual voltage and phase are incorrect, then try adding a few pF across the RX cap until you get the right values.

As porkluvr says, you'll really need a scope to do this properly.