TESORO GOLDEN SABRE

[Max]

Hi,
Max.
So,TX sin is ok, p-p is ok.
You can see here TX/RX.Is this ok?
The coil disc good.Only sensitivity is poor.Why?Where I have to look for problems?
Thank you very much.

Hi,
from what I see seems you have 190° phase out of RX vs TX. Ok... seems not bad at all... Tesoro's coils for uMax series have around 200° phase shift... that's cause you have about good discrimination.

You have to check... if signal of RX shift to the left when you put near a target.

Also, another useful test is checking if coil is overbalanced or not. What do you see if you near silver there...? I mean is there initially a reduction in rx amplitude , then it starts to rise or just rise always ?

You have also to measure rx voltage when no target at out of preamp...(form picture seems you have 300mVpp there but it's out of focus so I can't say for sure... but if so... gain is 43... so you have about 300mVpp/43=7mVpp nulled coil) then divide by gain to get actual nulled voltage... simple calculation required.

Why poor performance... ? Uhm... coil seems about good... maybe problem is at components... do you use different than good ones (e.g. LM308 and the like) ?

Kind regards,
Max

[Ultimate_Haze]

[quote=Max;91814]Hi,
from what I see seems you have 190° phase out of RX vs TX. Ok... seems not bad at all... Tesoro's coils for uMax series have around 200° phase shift... that's cause you have about good discrimination.So that is about ok.

You have to check... if signal of RX shift to the left when you put near a target.
Yes when I put coin close to coil I can see that RX move left.

Also, another useful test is checking if coil is overbalanced or not. What do you see if you near silver there...? I mean is there initially a reduction in rx amplitude , then it starts to rise or just rise always ?
What do you mean?How to monitor the amplitude?
If I near silver coin to coil I see small voltage reduction in RX signal.Then quick increase and then the normal value there.0.375
/353 pin7/

You have also to measure rx voltage when no target at out of preamp.Do you mean pin7353 or across RX leads?..(form picture seems you have 300mVpp there but it's out of focus so I can't say for sure... but if so... gain is 43... so you have about 300mVpp/43=7mVpp nulled coil) then divide by gain to get actual nulled voltage... simple calculation required.
How I determinate gain value?

Why poor performance... ? Uhm... coil seems about good... maybe problem is at components... do you use different than good ones (e.g. LM308 and the like) ?

I have used LM308

Thanks for your attention.I now its slow progress with my poor skills.

[Max]

[quote=Ultimate_Haze;91818]

Hi,
from what I see seems you have 190° phase out of RX vs TX. Ok... seems not bad at all... Tesoro's coils for uMax series have around 200° phase shift... that's cause you have about good discrimination.So that is about ok.

You have to check... if signal of RX shift to the left when you put near a target.
Yes when I put coin close to coil I can see that RX move left.

Also, another useful test is checking if coil is overbalanced or not. What do you see if you near silver there...? I mean is there initially a reduction in rx amplitude , then it starts to rise or just rise always ?
What do you mean?How to monitor the amplitude?
If I near silver coin to coil I see small voltage reduction in RX signal.Then quick increase and then the normal value there.0.375
/353 pin7/

You have also to measure rx voltage when no target at out of preamp.Do you mean pin7353 or across RX leads?..(form picture seems you have 300mVpp there but it's out of focus so I can't say for sure... but if so... gain is 43... so you have about 300mVpp/43=7mVpp nulled coil) then divide by gain to get actual nulled voltage... simple calculation required.
How I determinate gain value?

Why poor performance... ? Uhm... coil seems about good... maybe problem is at components... do you use different than good ones (e.g. LM308 and the like) ?

I have used LM308

Thanks for your attention.I now its slow progress with my poor skills.

Hi,
gain is from differential amplifier formula... R2/R1 stuff = R4/R3 = in our case 220K/5.1K = 43 (that's Vo/Vi)

The voltage decrease/increase you must look at rx signal... when silver target is still far you'll notice very small variation look carefully or increase gain at vertical section of scope, focus attention on peaks... see if they move and how , if increase or decrease when far.

Then near the target an look signal rise.

Kind regards,
Max

[simonbaker]

[quote=Ultimate_Haze;91818]

Hi,
from what I see seems you have 190° phase out of RX vs TX. Ok... seems not bad at all... Tesoro's coils for uMax series have around 200° phase shift... that's cause you have about good discrimination.So that is about ok.

You have to check... if signal of RX shift to the left when you put near a target.
Yes when I put coin close to coil I can see that RX move left.

Also, another useful test is checking if coil is overbalanced or not. What do you see if you near silver there...? I mean is there initially a reduction in rx amplitude , then it starts to rise or just rise always ?
What do you mean?How to monitor the amplitude?
If I near silver coin to coil I see small voltage reduction in RX signal.Then quick increase and then the normal value there.0.375
/353 pin7/

You have also to measure rx voltage when no target at out of preamp.Do you mean pin7353 or across RX leads?..(form picture seems you have 300mVpp there but it's out of focus so I can't say for sure... but if so... gain is 43... so you have about 300mVpp/43=7mVpp nulled coil) then divide by gain to get actual nulled voltage... simple calculation required.
How I determinate gain value?

Why poor performance... ? Uhm... coil seems about good... maybe problem is at components... do you use different than good ones (e.g. LM308 and the like) ?

I have used LM308

Thanks for your attention.I now its slow progress with my poor skills.

With my prototype TGSL (not soldered) I only get about 20 cm on american quarter. Because I test inside house, there is much noise coming from coil. I know that because if I disconnect coil, noise much lower.

Just for information, a useful test is this -- put oscilloscope on about .1 cm/s, basically very slow.

Now look at output of each LM308. Dual trace is best if you have.

How does it look with no target signal. How big is noise? Move sensitivity control. Is there a point where the noise makes speaker beep, or is it always quiet?

Now wave target over coil and watch signal on scope. What is relative size of ground channel and disc channel signal?

If you play with disc control, you will see disc channel move in opposite direction from ground channel when you discriminate out the target.

I don't know why some people get more depth, they say it is due to coil. However, if your noise with no target is very low, it may mean you can increase the gain (or reduce the sensitivity threshold) to get deeper detection.

Cheers,

-SB

[fitos]

Hi,
Max.
So,TX sin is ok, p-p is ok.
You can see here TX/RX.Is this ok?
The coil disc good.Only sensitivity is poor.Why?Where I have to look for problems?
Thank you very much.

put new transistors j107 or bf245

[simonbaker]

TGSL1265 last.lay

Hi Ivconic:

I am not sure, but maybe small mistake on TGSL1265 last.lay layout.

See attached photo. It looks like pin 8 of U107 (LM358 ) is connected to +12v instead of +8v.

Probably not important, but noise from speaker is on +12v.

Regards,

-SB

[ivconic]

Well...i respected original schematic...

[simonbaker]

Well...i respected original schematic...

(Oh no, not another secret schematic... !)

Maybe reason for it is because U107b is used for battery check, so needs to have supply not dependent on regulator?

Never stop learning lessons from good old TGSL...

Cheers,

-SB

[ivconic]

No it is not secret at all!?
It is posted on very first page of this thread;

http://www.geotech1.com/forums/attachment.php?attachmentid=1977&d=1174874259

See?

[ivconic]

Looking at some questions and remarks here (least reffered to your question about schematic), on these pages...i oftenly ask my self: " Heck! Does people open and read all what was posted here?"
So much already posted and told here....
Aint not such thing as "secret" on TGS/TGSL subject any more here...
Everything already "chewed" so many times!
Just follow posts and read....

[Ultimate_Haze]

Hi,
Max.
I have try with silver coin and silver chain.
Can be seen small voltage drop.But that's rely close to coil for both items.I am preparing some videos.

SB.I will try this ASAP.Your words make sense.

Fitos.I am using BF245C.If you say so I will replace with new once.Now I have few PN4393 will test them too.

Ivconic.Soon there will be no place for such questions.As everything is already discused here.Rely hugh thread. And now its almost complete.Best amateur project ever.More complete then magnum and all.

[simonbaker]

No it is not secret at all!?
It is posted on very first page of this thread;

http://www.geotech1.com/forums/attachment.php?attachmentid=1977&d=1174874259

See?

It is my running joke that you and Max are magicians who can make metal detectors do things no one else can and have secret formulas... maybe I'm only one chuckling...

Yes, I see on that first schematic U107 is indeed attached to battery 12V+ -- I had not noticed that. Just about every other schematic shows it as regulator 8V+. How can we trust schematic when changed later... was it a mistake or truth????

I am beginner so I like things simple-stupid as possible. A PCB should match a schematic, not part of one schematic here, another there, for beginners like me. So I nitpick and make little corrections to help me and other beginners, no criticism intended. I also like to question what is best practice and why. Maybe annoying, but someone has to do it...

Cheers,

-SB

[ivconic]

It is my running joke that you and Max are magicians who can make metal detectors do things no one else can and have secret formulas... maybe I'm only one chuckling...

Yes, I see on that first schematic U107 is indeed attached to battery 12V+ -- I had not noticed that. Just about every other schematic shows it as regulator 8V+. How can we trust schematic when changed later... was it a mistake or truth????

I am beginner so I like things simple-stupid as possible. A PCB should match a schematic, not part of one schematic here, another there, for beginners like me. So I nitpick and make little corrections to help me and other beginners, no criticism intended. I also like to question what is best practice and why. Maybe annoying, but someone has to do it...

Cheers,

-SB

"...who can make metal detectors do things no one else can and have secret formulas..."

To tell you the truth; i dont like to be considered that way. Very bad thing if more people thinking the same way as you. Than all i posted here was for nothing - huge waste of time and energy.
This directly look as simillar charlatanism from Remote Sensing threads...i dont like that at all.
So...i should feel huge guilt cose nobody else (except Max and me) can not achieve 32cm in air for 1e coin????!!!
What a blast!? All the time i was blind here, beleiving that am accepted fairly here. Now i discovered (thanks to you) that actually i was considered here as plain fool by other members??? Plain fool who is posting rubbish and lie arround about results!??
Here in local...very near by my place, there are also 3 enthusiasts - beginners who already made dozen copies of TGSL. Those handmades are working even better. Much better than my handmades. I visited those guys and was pretty amazed with what i saw than. Also i am oftenly receiving mails from people arround the world with very nice reports and results they achieved. So...Max and me are not the only one. 32cm in air for 1e coin is nothing - not some achievement at all. Take any better detector on market and you will see much better air results... for example take Minelab Explorer Se or White's DFX and you will see twice better results...if not more better.
So i dont really understand such attitude...
Anyway, thank you very much for opening my eyes. In future i will take much care here, what to post and if i will post at all...
Very Best Regards!


Ah yes..about schematic, you should know that i only changed few things on TGS. Not much and nothing important changed there.
But to know that you must read this thread from the begininig, follow posts and understand what was posted.
So ...yes...that first schematic is original and most accurate. So as my last reduced TGSL schematic. In the between all other versions are also accurate and compatible with first one. You should know that already...but you didnt.

[ivconic]

Last time about this;
TGS/TGSL as any other work must be done very precisely. Coil demands huge attention and patience to be made correctly - only way possiblle.
Disregard any aside comments, focus on one schematic (doesnt matter which one) and make it. All versions already posted here are accurate. So as all pcb's. Each one will work very good if was made good.
If you cant achieve noted results - dont blame me,Max or anybody else. Blame your own impatience and inattention in process of making your handmade. Do not consider me as liar and charlatan cose i dont have slitest reason to "pumpup" reports here. No money involved...so why should i risk and lie? It is not some sf LRL device - it is ordinary,obsolete, analogue metal detector, projected far back in '80-s....very easy to reproduct in homemade arrangement.
So...what's a big deal???

[Max]

It is my running joke that you and Max are magicians who can make metal detectors do things no one else can and have secret formulas... maybe I'm only one chuckling...

Yes, I see on that first schematic U107 is indeed attached to battery 12V+ -- I had not noticed that. Just about every other schematic shows it as regulator 8V+. How can we trust schematic when changed later... was it a mistake or truth????

I am beginner so I like things simple-stupid as possible. A PCB should match a schematic, not part of one schematic here, another there, for beginners like me. So I nitpick and make little corrections to help me and other beginners, no criticism intended. I also like to question what is best practice and why. Maybe annoying, but someone has to do it...

Cheers,

-SB

Magician !? No... much more!

No... joking... , Ivconic's is right about thta stuff... the project is complete and accurate... anyone can replicate if enough skills, patience and money/time (very few indeed cause uses very ordinary components, apart fancy older LM308 stuff... all the rest is about junk level components today...)... for money I also consider that people who wanna top-performance must have a scope... or sacrifice time in experiments doing much coils than if having the scope handy.

That's all clone it... make it work and tune for best performances.

With e.g. PCB of TGSL by Ivconic you'll get wonderful behaviour... less chatters, less noise and increased fun!
Coils you know recipes... now have also many but results you said are with old DD coil Ivconic's design... very good and stable coil design, very hi performances if tuned ok.

Now... 32cm on air for 1eur!? Why not ? Why not more ?

Much more I will say... but all depends on HOW you replicate device... not on schematic or PCB layout file... much depends on you, that's the point.

When pushing things to the limit the stuff become HOT... you have to deal with extreme solutions also... choose right shield as example... minimize noise at circuit so use metallic enclosure, extra faraday cage and gnd coverage on board etc etc all no-standard but this will be an extra at performance. You'll select components also... choose what's best for what etc

What I'm trying to say is that average performance everyone can do ...it's like formula1 ...all depends on skills and money/time you have to spend... then you can be always in pole position or 10 lines back... depends on you and your attitude to success.

Kind regards,
Max