TESORO GOLDEN SABRE

[Fred]

Max,
The value of the cap below the "new" 33k resistor is missing.
A good idea would be to put numbers on the Ic´s so it is much
easier to find them on the pcb.
Just an idea,if you want to improve even more your work

My detector is working very poorly,25cm max ,disc and notch working,sensitivity makes no much diference.Some oscillograms are not the same than posted by you, i have work to do to find the fault(s).The output tx coil and output of lf353 are ok thought,180º and looking good.

This is part of the fun...i guess.

regards,
Fred.

[1843]

Max,
TLC2262 is much better than LF442 ?

Regards!

[Max]

Max,
TLC2262 is much better than LF442 ?

Regards!

Hi,
is good to reduce noise from the notch section. For that purpose it's very good.

Best regards,
Max

[Max]

Max,
The value of the cap below the "new" 33k resistor is missing.
A good idea would be to put numbers on the Ic´s so it is much
easier to find them on the pcb.
Just an idea,if you want to improve even more your work

My detector is working very poorly,25cm max ,disc and notch working,sensitivity makes no much diference.Some oscillograms are not the same than posted by you, i have work to do to find the fault(s).The output tx coil and output of lf353 are ok thought,180º and looking good.

This is part of the fun...i guess.

regards,
Fred.

Hi,
yes... was old mistake... I missed that... thanks.

New revision.

Kind regards,
Max

PS: I think that for part numbers would be better if someone will provide e.g. the original layout file... cause would be a bad thing erasing too much stuff to make room for them. It's easy adding them by the layout program instead of using image manipulations prog.

[ivconic]

What's the story with 3K3 resistor there? It is marked blue. Why? I never modded it...

[Max]

What's the story with 3K3 resistor there? It is marked blue. Why? I never modded it...

Hi,
in original PCB file was 3K9. If you use 3K9 you mod a bit disc section behaviour.

Anyway... no big changes. Try it.

Best regards,
Max

[ivconic]

Now i remember! I saw 3K9 on some schematic....
I might be check this..
Thanks!

[Fred]

Ok max, thanks,
I think making parts numbers on the ics would be goo, i can do that when i finish mine.

Ivconic, did you see my post about influnece of connecting cable AFTER nulling? what do you think about it?

So far the nulling i have done was at output of lf353 with scope and comparing phase with tx coil.its interesting to see that we can achieve almost same null voltage but with a slightly different phase between 2 coils.

Regards,
fred.

[ivconic]

Dont know how to null it without cable?
Even it was possible, later cable might distort balance in some (small) percentage...

[Fred]

Ivconic, this is exactly my point: you explained before how you null it with a capacitor and multimeter,so you are not using the final cable?
Regards,
Fred

[ivconic]

Of course i am using final cable when balancing! Who told you i wasnt?

[ivconic]

I guess this is a kind of missunderstanding!? I am using final cable when nulling coils.Simply as that.
Otherwise i dont know how to balance coil without cable?
If coil chords (to short) attaached directly to unimeter than must be very close, which will, on the other hand, provoke some induction in coil.
When nulling, i put coil on huge plastic table,1.2m away from soil,1m-1.5m away from nearest metal, and than null it. For example, when 0.000 on unimeter achieved, if i apply coin close to coil, than it will read 0.015-0.040mV...showing induction - logically!
As larger item applied close to coil, larger the reading on unimeter...A bucket (iron) will cause 0.1xxmV reading on unimeter....Simply as that.
You must be sure there is no metal arround coil when nulled.Otherwise you will "null" coil to present situation, which can be pretty falsed if some induction occured! Pay attention!
Further, i just have to attach and fix original cable to coil, to be sure i will null it as best as i can....So you may say - my coils are nulled including cable...Heh! If some errors; than those are pretty small.....but i dont thik there are any, due attached capacitor. Think about that.
Regards!

[Fred]

Ok Ivconic,
Thanks for informations!
When you said you were nulling with capacitor directly atached to coil, i assumed it was without cable.So it is a missanderstanding...Your precisions are usefull.
Thanks again,
Be cool!
Regards,
Fred.

[Fred]

I post here the schematic and parts layout with IC´s and transistors numbers.
In conjunction with the oscillograms from Max it is perfect for troubleshooting.

Regards,
Fred

[Fred]

Wrong IC1/IC3
corrected: