Tesoro Lobo news

[LukaZ]

it was done according to this diagram, my Lobo works at 17.5kHz, C14=250pf, the RX coil should be set to 18.1kHz, I haven't done that yet, and I still need to check exactly. IC, U4B, in parallel with C9, instead of a 100K resistor, a 500K trimpot should be placed, also, on Lm392 responsible for battery monitoring, instead of 3k3, a trimpot for fine-tuning the threshold is placed. I used a probe from a Golden Mask, and it is very close to the inductance of a tesoro probe, for a device at 17.5kHz

edit: I also had to remove R5, for some reason with it, IC7660 wouldn't work

[Maurizio2]

Please, can you publish the schematic revised correctly?

[LukaZ]

I would like to know if there is anyone who managed to complete Lobo successfully.

here it is. it works fine on the table;

https://imgur.io/a/AdWVphh

[ZOUjiarui]

Oh, and the schematic for the above post is 7808. lm2930 is hard to find

[ZOUjiarui]

He is different from the one on the pcb, is there a more common substitute?

[Mario-j23]

LM2930-8 Positive Regulator 8V, 150mA

[ZOUjiarui]

[ZOUjiarui]

What kind of component is the lm29808 in the power supply part? I can't find any information. Is there a substitute?

[Maurizio2]

1.about U5B ,SORRY i was basing on a previos posteted schematic where pin5 was grounded,
the FOMA and W.LAHR have right conections with pin6 grounded, sorry!!
-with R10 100k on sim. when you tourning disk.pot. a some kind of jumping was apearing on phase , but with biger value of R10 (150k and more ) has a good shift of 30-180deg
2.if you see on my picture the GEB channel is is on 0 DEG reference to RX signal measured at the output of the pre-amp (pin 1 of U7A) ,and if you see when it rise,it make slite curve whitch narrow the the accept region from -80 to +90 (narrows 180 to 170 deg),thats becouse to reject ferrite and ferromagnetics materials
- the center of accept region is 0-DEG
- with 30 to 180 on disc channel i refer to that ,the center of disc channel goes from 30 to 180 ref to RX signal measured at pin 1 of U7A
3.the pre-amp i call ,everything from input ay C4 to output at (pin 1 of U7A),
-yes ref signal is measured at the input of bf245(tis75)
-RX CAP i refer to parallel cap with coil
-try to get good sine on tx ,without good sine it makes huge changes at at GEB and DISK
-W.LAHR schematic it looks best with one mistake R14 from 1k ->10k (R10 sel.)

Hi Perdica!
I understood that R10 must be at least 150Kohm to have the right discrimination.
About point 2, I could not understand what was written, sorry, please if you can explain better.
Any other useful information is welcome.

[Maurizio2]

I would like to know if there is anyone who managed to complete Lobo successfully.

[Maurizio2]

Hi Waltr,
yes you are right, the coils can also be purchased on ebay.
However I have to say that my experience with buying used coils on ebay is negative.
In fact, I have purchased two coils over time but both with problems.
Maybe it was just a coincidence.

[waltr]

Or a used coil - maybe from Ebay

[Maurizio2]

Sorry, I discover today that Tesoro has gone out of business therefore the only solution is to self made the coil.

[Maurizio2]

I would like to try to build this detector, but to start I would rather buy an original coil. Which model should I take?

[homefire]

The one Eugene was working on was the most complete that I know of. I have a couple TGSL boards here thinking of Bumping freq up to 32Khz.