TESORO GOLDEN SABRE

[Max]

Darko and TikTak regards to you both! You asked simillar questions, reported simillar problems...logically i assumed there is one - same person. I still have doubts on that... Never mind! Regards to "both" !
Smoke you said!? There is no smoke without a fire , i said!

Back on subject;

Who pronounced idea that on pin 1. must be sinus??? Who was the first actually to said that?
I am sure there must be "clean" square, as i posted. If you want to be sure that everything is right there; replace 100pF with 220-330pF and after than scope it! Later we can talk...

Take another look on my video and you will see full transition from sinus to square when Disc. pot is turned full scale. If some jitters on the video bug's you, i must explain those are due old and "rusty" oscilloscpoe - it's inner hums... Generally video is good enough to see full transition in full range - covering whole amplitude...
You can test your device by scoping pin 2. of LM393...

Hi Ivconic,
why do you think that 220-330pF is the right value ?

In schematic it's 100pF. Of course... you will say that it works better with 220-330pF, and that you have square signal now... but then schematic has a mistake there ?

Do you think it's a mistake on schematic or that 220-330pF is a good workaround!?

Kind regards,
Max

[Max]

Hi all,
the simulator just don't care of zener voltage !

I cannot find the model for 3.9V so I've made my own 3.9V zener... "MAX" brand... (but it works!).

Effects of the whisky... don't care... but look at picture!

Kind regards,
Max

[ivconic]

Darko and TikTak regards to you both! You asked simillar questions, reported simillar problems...logically i assumed there is one - same person. I still have doubts on that... Never mind! Regards to "both" !
Smoke you said!? There is no smoke without a fire , i said!

Back on subject;

Who pronounced idea that on pin 1. must be sinus??? Who was the first actually to said that?
I am sure there must be "clean" square, as i posted. If you want to be sure that everything is right there; replace 100pF with 220-330pF and after than scope it! Later we can talk...

Take another look on my video and you will see full transition from sinus to square when Disc. pot is turned full scale. If some jitters on the video bug's you, i must explain those are due old and "rusty" oscilloscpoe - it's inner hums... Generally video is good enough to see full transition in full range - covering whole amplitude...
You can test your device by scoping pin 2. of LM393...

[Max]

Very good work Max!

Having studied the results of your analysis, I would conclude that the detector is working correctly, as designed. However, with the TGS Lite version, it would probably work better with the GEB and DISC sample circuitry from the Bandido II. I expect this would get rid of the spurious oscillations at pin1.
The main problem I can see is the oscillations at testpoint 12. These are the oscillations I've referred to many times, but everyone has denied this is happening! BUT - it's obviously there after all! This occurs for the simple reason that inputs to these comparators are hovering around the threshold crossing point, and random noise is causing the comparator to switch from one state to another. I would suggest that this is an area in need of improvement. The slight fluctuations at pin 1 are not actually causing any problems in the synchronous demodulators (as confirmed in practice by Ivconic) so IMHO I would ignore this at the moment.

Hi,
yes I confirm too that it works perfect even with the strange pin1 ringing... but it's interesting understand why sometimes happens and some other times not... even with same brand LF353N.

Yes at comparators there are fluctuations that are then showed as noise on speaker. On strong bursts (e.g. what I get with fakes 308s) they are so often present that one could see really easy on screen and hear from audio...

So you are 100% right on that thing... it happens cause of chain noise amplification... so would be better using some less noise affected amplifier in the middle to avoid much problems like that.

Best regards,
Max

[Max]

Hello Frends.

Made some test, chanced the Send TR 2N2907 and the stab. zenerdiode 4.3V. Replacment TRs were 2N3905 Bc557 zeners from 3.9 - 5V1.
The erretic noise had to do with this al.... !
Look at the results on LF353-1 !? ( Geo save some wisky ....hik ).

So care is needed in the transmitter part ?
I do not have the answers for this, maby Porklver can make simulation ?

Hi,
this is really interesting... so maybe is just overload signal from TX that make LF353 crazy ?

I have to try simulation with 3.9V or 5.1 but I can't find them on LTspice ???

I need some more whisky ! (Actually is "Baileys" not just whisky... and lot of smoke too...real fog now...)

Let me find some zener and I'll post a new simulations in matter of minutes...

Kind regards,
Max

[Qiaozhi]

Very good work Max!

Having studied the results of your analysis, I would conclude that the detector is working correctly, as designed. However, with the TGS Lite version, it would probably work better with the GEB and DISC sample circuitry from the Bandido II. I expect this would get rid of the spurious oscillations at pin1.
The main problem I can see is the oscillations at testpoint 12. These are the oscillations I've referred to many times, but everyone has denied this is happening! BUT - it's obviously there after all! This occurs for the simple reason that inputs to these comparators are hovering around the threshold crossing point, and random noise is causing the comparator to switch from one state to another. I would suggest that this is an area in need of improvement. The slight fluctuations at pin 1 are not actually causing any problems in the synchronous demodulators (as confirmed in practice by Ivconic) so IMHO I would ignore this at the moment.

[ApBerg]

LF353-1

The Send TR was not 2N2905 but 2N2906 !

See post 1426

[Darko]

re:


Actually, from my TGS couple days earlier come out a magic smoke and I know ,when this magic smoke come out from TGS he had tendency to don’t work anymore. This is really strange thing for me but this is what happens when someone is very impatient, like me. Now I waiting for new IC’s from local suplier.

Anyway, i am glad to see that you finally made coil with detection over 30cm...Bravo! Good job!

[ApBerg]

LF353

Hello Frends.

Made some test, chanced the Send TR 2N2907 and the stab. zenerdiode 4.3V. Replacment TRs were 2N3905 Bc557 zeners from 3.9 - 5V1.
The erretic noise had to do with this al.... !
Look at the results on LF353-1 !? ( Geo save some wisky ....hik ).

So care is needed in the transmitter part ?
I do not have the answers for this, maby Porklver can make simulation ?

[Darko]

lele bre,bas bas.

No ivconic, tiktak is not my friend.Yet.I think.And he could not be me. I am sure of that.


Hah,hah,hah!!!
What kind of question is that? How i dug those coins..!?!?!? Simply, i detected those and dug them, one by one...Simply as that.
TikTak you are, almost always, asking me simillar questions..? Why?
Like you "investigating something in my posts"? Are you Serbian? Bet you are!
Are you, by some strange coincidence Darko? Bet you are! Or one of his friends!? If you want something to say here, dont hesitate...c'mon spell it!
But please do not ask me questions like that anymore....
"Half of rusty horse shoe..."!? Is it possible that there are some terrains without horse shoes "installed" in??
How i couldnt detect horse shoe? Simply, there wasnt anyone there, where i went to propsect... Even if were, my Dscrimination circuitry works very well, also my coils are nulled perfectly, so there is NOTICEABLE DIFFERENCE BETWEEN sound produced by horse shoe and coin!

Anyway, i am glad to see that you finally made coil with detection over 30cm...Bravo! Good job![/quote]

[Max]

For Max. My LF353N is from National. I traced again the signal but this time as you.. channel1 on out of LF353(Rx) and channel2 on the pin1 of LF353. The signal is very good
To Ap. I use sockets and pin connectors, so maybe one bad connection. I connected the Rx capacitor (15nf) on the coil and i think that i am very good. But i am not sure. Now i have problem with disc. When i change the disc pot i see a phase shift but i have not responce on the metalls. It beeps in any position. Ohh my god, all to me are happened,
So the solution ia one.
I go to drink 2...3 whisky and after all will be OK.
Bye

nice! we have same parts and read different things... now I need a whisky too

[Geo]

For Max. My LF353N is from National. I traced again the signal but this time as you.. channel1 on out of LF353(Rx) and channel2 on the pin1 of LF353. The signal is very good
To Ap. I use sockets and pin connectors, so maybe one bad connection. I connected the Rx capacitor (15nf) on the coil and i think that i am very good. But i am not sure. Now i have problem with disc. When i change the disc pot i see a phase shift but i have not responce on the metalls. It beeps in any position. Ohh my god, all to me are happened,
So the solution ia one.
I go to drink 2...3 whisky and after all will be OK.
Bye

[Max]

Hello Frends.

Thanks for all the work you al have done ! Great is Internet !
I agrey with Ivica, the goldy light (golden sabre) with the right coil is a very good detector, it is working as top line detector !

But there are some strange things the signal at 353-1: I have LM393N and a LF353P think the N version is better.
The 'wrong' signal that Max has is the same as I had ,after reducing the TR signal !? (removed the stab.zener diode out the circuit)
So the TR signal, the C from 100pF and the Lf353 are parts in this together with Porklvrs 10K we have to find the answer. However with wrong signal it is also working !?

The problem Geo and I have:
Sometimes when i touch the pcb or the coil housing or any wire i have erratic signals (beep...beep...etc). Other times it works ok. I think that it must be shielding problem. If i will find it i"ll write you. I must go out to test it (when rain stops) because i am afraid that at my Lab there are a lot of parasitic signals.

The first board I made has no problems, the components are close on the board( no ic sockets) and connections are as short as possible, the second, testboard has lots off problems, I have long connections and use ic sockets !
I will tray to find out what is the main problem.

Best regards.

Ap

Hi Ap,
thanks for your reply... yes Internet make things really easy about echanging ideas... maybe also too much easy... anyway

I think that your thoughts about sockets and long wires are absolutely good... cause we always don't keep in mind there are side effects due to capacity involved using e.g. sockets and the like... BUT problem at LF353 pin1 is probably not caused by socket... I'm about sure of that cause I noticed that putting a TLC2262 there I get a totally different shape... and maybe that strange thing has much more to do with input bias current of op. amp. that's why I suppose the LTspice model of LF353 could be too good to be real.

But maybe I'm wrong ... who knows ?

What I know is that LF353 have 50pA bias and TLC2262 just 1pA... 50times less current! The TL082 has a typical value of 30pA bias at 25°C... but I suppose they are about the same thing compared to LF353 in same room temperature.

Maybe the simulator uses a different value ? I'm pretty sure that parameter is much involved in the ringing we see there...

The funny thing is that it works in any case

Best regards,
Max

[ApBerg]

LF353-1

Hello Frends.

Thanks for all the work you al have done ! Great is Internet !
I agrey with Ivica, the goldy light (golden sabre) with the right coil is a very good detector, it is working as top line detector !

But there are some strange things the signal at 353-1: I have LM393N and a LF353P think the N version is better.
The 'wrong' signal that Max has is the same as I had ,after reducing the TR signal !? (removed the stab.zener diode out the circuit)
So the TR signal, the C from 100pF and the Lf353 are parts in this together with Porklvrs 10K we have to find the answer. However with wrong signal it is also working !?

The problem Geo and I have:
Sometimes when i touch the pcb or the coil housing or any wire i have erratic signals (beep...beep...etc). Other times it works ok. I think that it must be shielding problem. If i will find it i"ll write you. I must go out to test it (when rain stops) because i am afraid that at my Lab there are a lot of parasitic signals.

The first board I made has no problems, the components are close on the board( no ic sockets) and connections are as short as possible, the second, testboard has lots off problems, I have long connections and use ic sockets !
I will tray to find out what is the main problem.

Best regards.

Ap

[Geo]

Hi Ap and Geo,
from what I know there are only 5 manifacturers of LF353:

- National
- Motorola
- STM
- Fairchild (but really obsolete now... and almost impossible to find)
- Texas Instruments

I've National's ...what's yours ?

Kind regards,
Max

I will tell you later when i will go to the Lab (in the underground )