TESORO GOLDEN SABRE

[GeorgeGW]

ivconic: new photo from the pcb...



i put the same resistors and capacitors... but i want to ask you something about tranzistors before i put on the pcb




for chopper, (2Ν2222 & 2Ν2907) - I bought BC547 & BC557,
for buffer, (2N2222) - BC547
for TX tranzistor i put the same.. 2N22907
and last for 2 FETS (J107) - I bought BF245

[gurdal]

Who? Me?
Right now it is not possible, i don't have neither one TGSL any more. All sold out!
Besides...video clips are showing nothing and proving nothing! There is always ways and methods to record video clip in manner to fool out spactators. If i want to persuade you in something - it would be very easy for me to record fraudulent video clip and show you some crap device that performs excellent, and vice versa.
Only very stupid and naive people rely on video clips!
This is forum no 1 for metal detecting matters. I am member (hopefuly) descent enough so to other members take my words seriously. If i say black is black and white is white....well...you better beleive me. Otherwise ...million video clips will not help you!

Hi ivonic test video eldorado.but I want to make your circuit,Can you give files ???
thanks

http://www.youtube.com/watch?v=awoPmfJazvo

http://img258.imageshack.us/img258/9691/brgeldorado.png

[ivconic]

Who? Me?
Right now it is not possible, i don't have neither one TGSL any more. All sold out!
Besides...video clips are showing nothing and proving nothing! There is always ways and methods to record video clip in manner to fool out spactators. If i want to persuade you in something - it would be very easy for me to record fraudulent video clip and show you some crap device that performs excellent, and vice versa.
Only very stupid and naive people rely on video clips!
This is forum no 1 for metal detecting matters. I am member (hopefuly) descent enough so to other members take my words seriously. If i say black is black and white is white....well...you better beleive me. Otherwise ...million video clips will not help you!

[gurdal]

If possible

[gurdal]

Add Video soil test

[ivconic]

Always try to keep as short as possible wires which connects pcb and commands. To make this task more easy you may use setup like on posted photo. Front panel (metal plate with commands mounted on) is closely connected to pcb with good contact to pcb gnd. Rear coil connector holder is also made from metal (or piece of Cu plate) and also good connected to pcb gnd. This way, good gnd "coverage" is preserved. S/N ratio is improved. Once this achieved - you may start soldering SHORT wires from pcb to commands. As short as possible.
Compact work with good soldering (not to much tin, not to few, no flux) is just first step to good working device. The rest is more easier.
Cheers!

[GeorgeGW]

Thanks a lot for help ivconic!!!! when i have new results from the construction i will post here!!!!

[ivconic]

Dennis i replaced the opamp.. but nothing..... i construct a new one!!!

ivconic: new pics!!! i will buy new components as soon as possible!!! thanks!!!

George your old pcb is very ugly and bad!
Your new pcb is excellent!
I guess that could be the source of your problems!
Apply "lotlack" (soldering catalysator&protector) on that new pcb. Once dry, you may solder components on it. But be neat and try to do clean work. Do not apply so much tin! Try to void flux layers like on previous pcb.
Try to do clean and neat job - "mother of good electronic" !

[ivconic]

Hi Qiaozhi ,

Thanks for your reply ,

At this time on a 2 euro coin about 25 centimeter and on a 1 euro I think about 15 - 20 cm or worse .
My wifes (flat)iron 30 cm hahaha.
The only thing I've 'discovered' on sight was the difference in caps used: that's why my first question was posted .
I hope I get some performance improvement there.

The nulling of the coils is in my opinion good , with a multimeter 0 mV and with the scoop aprox 60 mV directly measured on the Rx coil and I've also played with different values of nulling ( 60 -80- 100 - 120mV etc) offered to the first opamp stage due to the S/N ratio .
I've tried , I think , almost everything posted here : reversing the coil leads , put one of the coils in the other direction , correct start -end configuration , used shielded cable from the pcb to my pot meters (I thougt I've measured some small noise transmitted from the previously used cables) etc etc .
So if anyone discovers any 'desparation' in my posts ...

regards Danny

???
That seems strange. Usually, when all done properly , TGSL should detect 1e coin easily at 31-32cm distance in air (Disc mode, Sense to max, no chatters, ferrite rod 10cm long totaly rejected)..
Be sure that you used LF353, 2x LM308, etc...etc... TX transistor can be 2N2907 or BC327 (many other similar too).
Negative voltage can varry from -6.00 to -6.30V.
???
Strange!?
I only got low distances with not so good nulled coil so far. Doubt in coil remains in your case too.
What about ferrite? Take 10cm long ferrite rod and check if it is fully rejected up to 5cm away from coil surface.. Than check with some small and thin silver coin is it accepted at the same adjustments when ferrite rod is rejected... Inform us here.
Cheers!

[GeorgeGW]

Dennis i replaced the opamp.. but nothing..... i construct a new one!!!

ivconic: new pics!!! i will buy new components as soon as possible!!! thanks!!!

[Dennis the Mennis]

Ofcourse the distances are measured in air.

[Dennis the Mennis]

What detection depth are you currently seeing for various targets?

Hi Qiaozhi ,

Thanks for your reply ,

At this time on a 2 euro coin about 25 centimeter and on a 1 euro I think about 15 - 20 cm or worse .
My wifes (flat)iron 30 cm hahaha.
The only thing I've 'discovered' on sight was the difference in caps used: that's why my first question was posted .
I hope I get some performance improvement there.

The nulling of the coils is in my opinion good , with a multimeter 0 mV and with the scoop aprox 60 mV directly measured on the Rx coil and I've also played with different values of nulling ( 60 -80- 100 - 120mV etc) offered to the first opamp stage due to the S/N ratio .
I've tried , I think , almost everything posted here : reversing the coil leads , put one of the coils in the other direction , correct start -end configuration , used shielded cable from the pcb to my pot meters (I thougt I've measured some small noise transmitted from the previously used cables) etc etc .
So if anyone discovers any 'desparation' in my posts ...

regards Danny

[Dennis the Mennis]

I dont leave it for a detector from a shop, i made two detectors ( delta-pulse and Garys PI detector ) and works good.... i will try it again from the scratch with new pcb with the same parts, I know TGSL is a good detector.

Hi George W ,

perhaps a stupid question : but what happens if you remove the 358 ( ic 107 ), this one should trigger the alarm / speaker .
possibly this way you can locate the problem ...

regards Danny

[Qiaozhi]

The problem remained : very low detection hight ... so I've ordered new caps of the type you've suggested and I'll cross my fingers when replacing them .

regards Danny

What detection depth are you currently seeing for various targets?

[Dennis the Mennis]

It is unlikely that the low sensitivity is caused by using ceramic capacitors throughout the design. Polyester caps would be preferred in the TX and RX circuits, but not essential. Ceramic caps are best for coupling, decoupling and filtering. If you change the TX and RX caps for polyester types, I doubt you will notice any difference.

Please define what you mean by "low sensitivity". Presumably you are referring to detection distance?

Hi Qiaozhi ,

Thanks for your reply ,

Yes I was referring to the detection distance , I am reading this thread for many weeks and collected all data I thought was necessary before I've started my project hoping I would reach the Finish without any help .
So I'm lost somewhere down the track but I don't know which way to the finish .
I will change the 'cheap' ceramics and I'll see what will happen.

I've managed to get all scoop signals as posted on page 57 by Max ( also collected in the PDF file ' TGS1 Compare.pdf ' ) , this could be also very usefull for the others started this project.
I am still focussing on the 'all metal' mode for starters.

I've also made another set of coils matching also the required specs but the problem remains , so I don't know if I can exclude the coils as the possible problem.

My puzzle continuous...

regards Danny