Unbalanced coil...

[ivconic]

...


"...don't understand why I get with lower sound..."

Same thing with G.Sabre...??
Unlike Classic 3, which have same sound on targets no matter of depth?
It will be much better if we can mod this on our Tesoros and gain same level of sound, cose i noticed; it is possible not to detect deeper coins or not to observe any changes in it because of that...
Any ideas?
Regards!

[Geo]

maybe is the point that the detector detect and "no" detect the object ..."big depth", so you have a averange "lower level" sound.
Bye

[Max]

"...don't understand why I get with lower sound..."

Same thing with G.Sabre...??
Unlike Classic 3, which have same sound on targets no matter of depth?
It will be much better if we can mod this on our Tesoros and gain same level of sound, cose i noticed; it is possible not to detect deeper coins or not to observe any changes in it because of that...
Any ideas?
Regards!

Hi Ivconic and Geo,
the fact is that there will be some kind of halo...1 year buried coin produce small one in slight mineralized soil...I've tested before with pulse induction and effectively I get bigger response on same target after 1 year...anyway seem that tesoro's have no big sound stage but the last op amp lacks where on distant targets near to the detection extrem point.
A solution could be an isteresys comparator (shmitt trigger) after it and that will control a fixed tone generator (e.g. ne555 astable mode or similar) cause with a controllable isteresys of say some mV range it can give signal-no/signal at its output even where the actual config gives as results only very weak sound. Isteresys is needed cause there is always some kind of small noise signal in the signal path...and an absolute level comparator could switch also on small uV transients there causing much falsing.
Another good idea could be not interfacing tone generator directly but by an optocoupler e.g. 4n33 or something similar.
I think that modify audio stage is possible but don't know if there could be drawbacks due to instability introduced by other components that require supply current that e.g. actual convercter can't deliver.

At the moment I can ear distant targets only using bigger headphones with good dinamic speakers instead of smaller ones that gives me too weak sound.
On bigger I have something 18ohm speakers...about 5cm round...and I can ear small signals but abrupt sound e.g. on the 1 eur at 30cm depth.
On 20eur-cent instead I get loud sound ever.

Best regards,
Max