lobo improved

[aft_72005]

Hi maxbiri
Please

What’s cad soft name that you designed lobo PCB?
Best regards.

[maxbiri]

Attention!

I'm testing lobo's power supply stage and found a error, i will solve the problem and post a correct schematic and pcb asap.

Byr Max

[maxbiri]

Hi all

All pdf are scale 1/1 300 dpi eccept schematic of course.

Bye Max

lobo improoved

Maxbiri .
What software forPCB design you are useing ? How come pdf folder so small ?? Waiting to see your-final works lobo!!!bye

[maxbiri]

Here is a photo of milling pcb.

[maxbiri]

I started split lobo schematic.
Here you find schematic and pcb for the first part:supply stage, tx stage, audio and battery check stage.
I do same other little improvement in supply stage for that i hope will be a better simmetrical power stage.

Bye Max

[aft_72005]

No, i havent built and tested, as i said i 'm not happy whit it

Any way you’re working very well.

i would likel split design into 2 pcb

Also I am interest and waiting to see your split design.
What’s cad soft name that you designed lobo PCB?
Best regards.

[maxbiri]

Hi AFT

No, i havent built and tested, as i said i 'm not happy whit it and i would likel split design into 2 pcb , i need find time for these new project!

Bye Max

[aft_72005]

Finally here is a pcb design for lobo rev1.

Hi maxbiri
You are working very good and fast . are you build and test your lobo PCB?
Best Regards.

[sirkut]

I may have to give this pcb a try. Thanks!

[maxbiri]

Finally here is a pcb design for lobo rev1.
Not happy with this layout, too much bridge in terrible position and a very crowded pcb but this is the best i can do on single side.
I'm thinking about split circuit in 2 pcb, one with only tx stage, power section and audio stage and second pcb with only rx and filters stage.

[maxbiri]

I Max

I'm agree with you about standard lobo's coil, so may be that the test is a little falsed.
More or less all tesoro schematic are similar but i think that lobo is a little different.
Tx stage is forced by 555 and not a pure LC oscillator as in silver, eldorado ecc ecc.
The tx stage is equal at diablo or similar at fisher 1280-1266 ecc ecc.
tx F is 20 khz and not around 10 khz as other tesoro's device.
Filter stage look as all other tesoro design with little difference.
I like thery much eldorado and it's discrinating power and power line immunity.
From lobo i aspect same power as eldorado but a better sensibilty to small target.
On eldorado i have about 30 cm for 1 euro coin in air and disc mode.

Bye Maxbiri

[Max]

Hey guys look at this, Lobo is high rated!

Hi,
you must consider that Lobo have standard coil 10'' DD... so the gain in depth is partially due to coil employed respect to e.g. eldorado.

Sure is a good one by tesoro... but coil is important too in such considerations.

I mean they are all similar about e.g. TX stage, power... and components employed so the depth is about the same for same coil type and dimensions... I think TGS has exactly same power of Lobo, but cause Tesoro sold it for other purposes (nugget hunting mainly) it was discredited as low depth capable... though there isn't really... just you need proper coil for it.

Just my 5cents

Kind regards,
Max

[strujas]

Hey guys look at this, Lobo is high rated!

[porkluvr]

LS404 substitution

Yes LS are obsolete an difficult to find i plan use TL072 oe lf 353 but any hint about other ic are wellcome!

MC33178 dual, and MC33179 quad are very similar to the LS402 and LS404.
These have much lower noise than TL07x, and consume about 1/2 less power. MC3317x (and LS40x) also can swing their outputs closer to the supply rails, compared to TL07x.

I intend to use MC33178 for the two receive amplifiers, and maybe use MC33172 for the discriminate control phase shifter and the sensitivity control buffer. MC33172 is a relatively noisy amp, but it uses much less power than the MC33178. I think it will be OK because low noise is not so critical in those two circuits. MC33172 also has (almost) rail-to rail output, and sufficient speed.

Good luck with your PCB. I have one in the works - planning to convert my Silver Sabre II into a LOBO. The power supply circuit is being reworked because my SSII cabinet only holds two 9V batteries. I will have a seperate power board mounted over the signal board and probably use a LT1615 low power switching regulator. The switching regulator is giving me headaches, (trying to get the most power-efficient configuration) but I think it will be worthwhile. My battery low circuit will be an LED flasher instead of audio.