TESORO GOLDEN SABRE

[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!

[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" !

[GeorgeGW]

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

[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!

[gurdal]

Add Video soil test

[gurdal]

If possible

[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]

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

[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

[GeorgeGW]

ivconic good results!!!!!!! TGS is working perfect!!! thanks for your help



this is the last construction for 2009 !!

[ivconic]

ivconic good results!!!!!!! TGS is working perfect!!! thanks for your help
this is the last construction for 2009 !!

Excellent!
Perform some air tests and inform us here!

[ivconic]

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

Here are my files! Those are accurate and workable! Working excellent!

http://www.geotech1.com/forums/showt...light=eldorado

[ivconic]

George correct me if i am wrong; but this cable you took from keyboard? Right?
That cable is maybe good for table testing but not good for outdoor. You better replace it with something more sutiable.

[ivconic]

Proper cable looks like this;

[Gwil]

Cable screening

Hi Ivconic

Your diagram is interesting. I always assumed that the transmit and receive cores in the cable needed to be screened from each other to prevent capacitive coupling between them, but maybe it isn't important after all (I'm still learning about this stuff). If one overall screen is good enough, it makes it a lot easier to find suitable cable. Does anyone have experience of using cable with one screen compared to cable with separate screening for Tx and Rx cores? Or is it unimportant?

Gwil