TESORO GOLDEN SABRE

[tiktak]

Hi,

Hi,
Max.
Can you give more details about this circuit.Because I have found that the problem is in the multimeter that I use for nulling coils!When conect like you say to try to null I have noticed that when I reach 0.00 mV the zero moment is now short,but wide!I can moove noticable distance RX over TX and multimeter reads 0.So I am pretty shore now that this is waht is messing me!
What multimeter did you use for sucsesfull nulling?
Thanks

[Darko]

Hi Max, Ivconic and others,

I think that Royal sabre is better than Golden sabre. Here is its shematic:

[ATTACH]3358[/ATTACH]

It has additional controls like pinpoint etc.

What do you think? Both are similar... so you can simply try Royal Sabre on your Golden sabre pcb.

Regards,
1843

Hi 1843!

Do you have some file or jpg of Royal Sabre PCB?

Regards,
Darko

[detectoman]

question for anyone:

i purched one oscilloscope used this day, of name tektronics tipe 422 in 100 dollars
have anyone opinion on these?
is good?
or is discontinued?
what say me
thanks
apologies bad english
detectoman

[Darko]

One strage thing happend with my TGS before 308s go to the rest. I don’t know, maybe by mistake i shorted some connections, I don’t know, but after I put all IC’s (except LM308s) in sockets and turn TGS On ,audio tone become very loud wille detecting. I mean very loud! Loud like in batt test! And without changes in sensitivity! With good sensitivity even with nonchalant nulled coil. Also, like Max explain: "with 1M instead is a totally flat response, always loud... independently by target size or distance...“. But there on my PCB that 1M resistor was omited! After that 308s go bye, bye. I think. Now all is the same but sensitivity go down and audio become barely audible. So seems here I have some ghosts. Or just I have to learn much more about electronics.

Regards,
Darko

[ivconic]

Ivica who is the voltage tension at Serbia (230V or 110v). I want to know what to do with chargers for (video camera and mobile phone).
Regards

230V of course!

[Fred]

I dont want to insist but there is no point in making a mv-meter if there is already one on the board, and (supposely)tuned to the right frequency:just measure your voltage at the output of 1st opamp. You will have excellent sensitivity.The best nulling i was able to achieve so far was around 50mv (on a scope).
Of course there may be exceptions,as the ones who want to make "universal coils"

Regards,
Fred.

[Darko]

Hi,
the important is , at the end, that you are satisfied of your work with TGS ! So have few meaning if use one tool or another... everything is good if you can reach objective... that seems a Machiavelli's phrase but is plain truth about electronics DIY projects.

And seems you are near solving of other small problems: very good.

Let me know about how things go on with your detector... if there are some other problems or if you need some advices... that's why this forum exist.

I'm sure Ivconic and other people will give their help too and common brainstorming could make our experience with TGS more and more enjoyable.

Best regards,
Max

Thank you Max for helping me. Also others here willing to help. Ivconic was help me so many times about Cl3 and now with TGS and always when is too hard for me to explain problem in english i call him at home and borring him, and strangle him and hi always with patience listen to me and trying to help. I'm just hobbyst and try to learn more about electronics. And building such project like TGS for me is really challenge, especially if machine will work ok for me. I'm not trying to become expert, just learn some more, so, expensive gadgets, osciloscopes etc is not for me. I will tray to make one milivoltmeter from schematic ivconic posted here earlier or from this one you post here. When I replace 308s will see how TGS works with and post here my impression. Maybe this will help someone like me who just likes to play with electronic staf and on the way learn something more.Thanks all.
Best regards,
Darko.

[Max]

Hi all,
here is a website with a project like I mean for people having problems reading small voltage values using bad meters:

http://sound.westhost.com/project16.htm

Of course, maximum resolution seems limited to 3mV but it's not bad considering that a few of real multimeters can gain such a precision on the e.g. 200mV scale for signals of 10-15KHz frequency.

So take a look... I've also others (somewhere) printed stuff but cannot find at the moment so posted that reference to the website of above.

The meter circuit is like in the picture ... one op. amp... some diodes ... all easy stuff.
If you wanna do even better use some more discrete components, fet etc...picture below.

The complete project require another part (attenuator) but for nulling coils it can be omitted just limiting readings in the lower range only.

If you haven't a scope or a very good multimeter I suggest you think at it as an alternative for nulling coils.

Best regards,
Max

[Max]

Yes ivconic, you are right in that way, but my problem with TGS was't nulling but sleepy LM308AN, both of them, just as Max sugested to check them and replace. I don't have problem with nulling at all! I nuling using AudioTester Osci even i knew you disagree with this way of nulling. I think, software like is Audio Tester is good enough for nulling coils and trick is only in proper calibration of these. I order pair of LM308H in metalic case like as you sugested here and I'm sure TGS will work great, just like before i burn it! Anyway, thank you for sugestions and help. About my unimeter,I'll just readjust him and will be good until i buy new one. Then i will try hammer on it.
Regards,
Darko

Hi,
the important is , at the end, that you are satisfied of your work with TGS ! So have few meaning if use one tool or another... everything is good if you can reach objective... that seems a Machiavelli's phrase but is plain truth about electronics DIY projects.

And seems you are near solving of other small problems: very good.

Let me know about how things go on with your detector... if there are some other problems or if you need some advices... that's why this forum exist.

I'm sure Ivconic and other people will give their help too and common brainstorming could make our experience with TGS more and more enjoyable.

Best regards,
Max

[Max]

"..My multimeter is liar!..."

Use 5kg hammer and kill it!
I still beleive you have problems with coil balance. Why? Simply, as you told me berfore, you dont have neither good unimeter, neither scope...to null coils. The hell!? How did you expected to null coils accuratelly?
In the past i also nulled few coils relying on my "hunch" and audition....Later when checked on unimeter or scope, i found out some residual voltages over 50-80mV..!!! "Hunch" my ***! I killed those coils with that famous hammer...of mine!

Hi,
...yes I know what you mean... really coloured way to say that!

Sometimes better using hammer and take some rest from multimeters and other strange things...I mean when they make you crazy!

I think that also a good old AC millivoltmeter could be better of many made in somewhere things... when they are just crap instruments.

That's why I suggest people here of rediscover some old funky projects with just one op. amp. to apply on some old analog meter... much much better than a 2eur no-brand-multi-lies-meters.

Best regards,
Max

[Darko]

"..My multimeter is liar!..."

Use 5kg hammer and kill it!
I still beleive you have problems with coil balance. Why? Simply, as you told me berfore, you dont have neither good unimeter, neither scope...to null coils. The hell!? How did you expected to null coils accuratelly?
In the past i also nulled few coils relying on my "hunch" and audition....Later when checked on unimeter or scope, i found out some residual voltages over 50-80mV..!!! "Hunch" my ***! I killed those coils with that famous hammer...of mine!

Yes ivconic, you are right in that way, but my problem with TGS was't nulling but sleepy LM308AN, both of them, just as Max sugested to check them and replace. I don't have problem with nulling at all! I nuling using AudioTester Osci even i knew you disagree with this way of nulling. I think, software like is Audio Tester is good enough for nulling coils and trick is only in proper calibration of these. I order pair of LM308H in metalic case like as you sugested here and I'm sure TGS will work great, just like before i burn it! Anyway, thank you for sugestions and help. About my unimeter,I'll just readjust him and will be good until i buy new one. Then i will try hammer on it.
Regards,
Darko

[Geo]

Ivica who is the voltage tension at Serbia (230V or 110v). I want to know what to do with chargers for (video camera and mobile phone).
Regards

[ivconic]

"..My multimeter is liar!..."

Use 5kg hammer and kill it!
I still beleive you have problems with coil balance. Why? Simply, as you told me berfore, you dont have neither good unimeter, neither scope...to null coils. The hell!? How did you expected to null coils accuratelly?
In the past i also nulled few coils relying on my "hunch" and audition....Later when checked on unimeter or scope, i found out some residual voltages over 50-80mV..!!! "Hunch" my ***! I killed those coils with that famous hammer...of mine!

[Darko]

Hi,
my circumference of nails pattern is exactly 64.5cm.

If using 1M resistor is all about the same you probably have some bad thing before comparators... could be some IC like TL081 or the like... cause I noticed a huge difference when 1M is in the circuit:

comparators saturate at minimum signal , even from far and very weak from small targets... where with just diode it isn't... and I get a very small audio response like tic-tic from speaker... not a good and loud tone.

With just diode the response is progressive... nearest the target, louder the response; with 1M instead is a totally flat response, always loud... independently by target size or distance...so kind of real comparator action (with very sharp rise/fall edges).... also you can understand if target is far or near just hearing the sound lasting less or more, but not about intensity that's always the same.

Check the LM308s part before comparators... also try different ICs there.

Best regards,
Max

Sorry,sorry sorry.... Freq is 14.631. I check again now with SpectraLab. My multimeter is liar! I must buy new,good one. So, nothing wrong with my coil i build as ivconic and Max described here. Also LM308 s i will replace when i get new ones. Thank you Max. I think problem is solved.

Best regards,
Darko

[Darko]

Hi,
The Zener diode is also very important for frequency,you should check its value and polarity.
Fred.

Thanks Fred,
I already leplace Zener with new one. Also replaced 1N4148 near Zener. I suppose my coil is not good. I making former in way to design it in eMachineShop, then print drawing and glue to the wooden board. I'm designed it following pictures posted by Max. I dont know where i'm make mistake in drawing former but for sure fault occured.