Building Wolf Treasure [Tesoro Lobo]

[mermelado]

Aaah, but C5 (and some other components that got penciled in) is not part of the original design. However, after changing the transmitter frequency, fiddling with bandpass filter components, and having to build a diy coil, playing with C5 may very well be a quick fix. I am trying to adjust anything else, to avoid having to add a parallel resonant capacitor. I figure there is a good reason the design is what it is.

I believe spice simulations help me get the circuit in motion, but I do not know what exactly will happen as a properly nulled coil is introduced, in the real world.
Will the receiver phase get advanced (I think) or retarded, and exactly how much, I do not know. I hope to find out in person. Keep in mind, the factory Lobo came with a concentric coil, not a DD, and they will each align somewhat differently, and well, everybody knows that.

The only reason I can think of for the original design to have no C5 and consequently the RX coil acts as a broadband coil. is that they had planned the possibility of using different coils. Perhaps with the intention of lowering TX to detect more common targets. I wonder if this will not vary the phase and null point? I have not seen the original Lobo design, so I can only speculate.

[rolling rock]

Phase between transmit reference and receiver changes with frequency. I can watch the phase increase and decrease while sweeping the excitation. I would like to post my results except that it is difficult to really pick out the individual traces, one obscures the other as they overlap, but I will try some more.
One thing to look out for, is that the receiver signal gets advanced when going into the JFET switches. The leading or trailing edge of whichever phase reference will appear to be leading the amplified rx signal peak significantly, at the point t where the demodulator output changes sign. Very tricky. I will try and show that too, but I am low on fuel so it will have to wait until next week. Time to go solar.

[mermelado]

Phase between transmit reference and receiver changes with frequency. I can watch the phase increase and decrease while sweeping the excitation. I would like to post my results except that it is difficult to really pick out the individual traces, one obscures the other as they overlap, but I will try some more.
One thing to look out for, is that the receiver signal gets advanced when going into the JFET switches. The leading or trailing edge of whichever phase reference will appear to be leading the amplified rx signal peak significantly, at the point t where the demodulator output changes sign. Very tricky. I will try and show that too, but I am low on fuel so it will have to wait until next week. Time to go solar.

I still haven't received the pcb from ebay, so I'm not in a hurry

[mermelado]

Hi friends I made the coils and ran them with the coil generator with this data:
TX = 17.83Khz + 40.9nF (+ 10nF in generator)
RX = 14.62Khz + 10nF in generator.

Other data obtained from the coils:
TX = 51 turns, 0.255 mm. (30AWG), diameter 207mm., 51.1 Ohm., 1.588mH.
RX = 145 turns, 0.202 mm. (32AWG), diameter 207mm. , 11.03 Ohm., 11.615mH.

It catches my attention that they use a different section of cable in TX and RX. I wonder why TGSL will use the same for both coils and it makes me want to experiment with that.

[Ruben2000]

It is because you have to respect the inductance and the ohmic rating of each coil; it also depends on the diameter of the sensor you are going to build.

[rolling rock]

It catches my attention that they use a different section of cable in TX and RX. I wonder why TGSL will use the same for both coils and it makes me want to experiment with that.

What would you be trying to change? Weight could be one answer. Of course you would not reduce the transmit wire size unless you like changing batteries more often. But using thinner rx wire will possibly cause your coil to become more affected by temperature changes. Don't overdo it.

[mermelado]

What would you be trying to change? Weight could be one answer. Of course you would not reduce the transmit wire size unless you like changing batteries more often. But using thinner rx wire will possibly cause your coil to become more affected by temperature changes. Don't overdo it.

Decreasing the cable section in TX increases consumption? As for what to change, it is not that I want to change, although using aluminum cable to reduce weight is something interesting to try, but it must be taken into account that its resistance per square centimeter is greater.
Actually, I'm sick of buying cables of so many different sections and I never and never have the correct section at home
It is also out of curiosity to know why TGSL uses the same section

[mermelado]

It is because you have to respect the inductance and the ohmic rating of each coil; it also depends on the diameter of the sensor you are going to build.

I do not think that the inductance undergoes great changes, perhaps the issue of ohmic resistance is the key, or perhaps the man who designed that coil, calculated it according to his availability. I think the best thing is to do tests on how much the detector has mounted and that is still missing, since I do not have all the materials yet. Thanks for your reply.

[mermelado]

Well gentlemen, I finally have all the PCB components assembled, except for the capacitors whose value must be determined by trial and error, now I am going to make the coil. I will report on my progress.

[Ruben2000]

Well gentlemen, I finally have all the PCB components assembled, except for the capacitors whose value must be determined by trial and error, now I am going to make the coil. I will report on my progress.

[ATTACH]56143[/ATTACH]

Excellent jam, you inform us about your progress. I've had to let it dust my PCB, I've been busy with other things. I see that LOBO is very difficult to make it work, I see several different schemes in various LOBO forums, there are some that have been successful and others have not, you have to be patient and read the forums to be able to deduce which error one makes at the same time there are so many details that one does not know which is which.

[mermelado]

Thanks Ruben:
I must be a masochist. Look that there are well-documented projects and I get to ride the Wolf "LOBO". I guess I like challenges and since basically all Treasures are very similar, I think that my great experience failing with TGSL will help me

[rolling rock]

Thanks Ruben:
I must be a masochist. Look that there are well-documented projects and I get to ride the Wolf "LOBO". ... I think that my great experience failing with TGSL will help me

Errk... I'm not trying to get rid of you, but because the Lobo is so much harder than TGSL you might better go back and master that relatively simple two filter thingy before messing with this monster. I think TGSL design is much less demanding of the builder and you have about a zillion coils to choose from.
You're not a masochist, you probably just have a death wish.



Don't we all!

[mermelado]

I made a lot of mistakes building TGSL, but I think I hit all the problems, but I got bored and decided to park it for a while. For some reason I wanted to ride the Wolf, if it doesn't work, then nothing happens either, I will always learn new things and by the way then I will publish the first one I have learned, in case it works for someone. Anyway thanks so much for your sensible advice

[mermelado]

My news

After my first tests, which have not been bad at all, I have come to the conclusion that the switches are wrong or poorly explained in almost all the schemes that circulate on the network, the same happens with the photos of the switches. Too It gives the impression that the fact that these types of switches go the other way around, that is, that when the lever is up they actuate the lower pins and vice versa. To clear up all this mess, I find it essential to understand how the entire complex Lobo switching system works, so the first thing I have done is to translate the manual into Spanish with some help from Google and now I am going to start studying it. I take this opportunity to share my work in case a Spanish speaker is interested.
Greetings to all and I will inform you all of my advances or setbacks

[Op04]

Here the old version schematic made by guru Darko posted a long ago in TGS thread, I dig so many deep page to get this, the schematic is easier to read. I still don't know if this schematic verified or not