Tweet
Originally posted by ivconic
View Post
This debate turned to very interesting and educating. Thanks to both of you guys.
I agree, TGS is not easy to improve. Generally i am very satisfied with what i gained so far. TGSL preforms excellent on small coins in ground.
But...main goal here is not to make device and stay satisfied with it!
Right?
Main goal for me is to constantly experiment and try to improve it at least a bit. So i did "million" small experiments and mods. Most of those gave no improvements. Very few gave some results. I can name a list of all what i done so far, but no need for that. I focused latelly only on audio stage cose that showed to be weakest part of design. BD140 version gives good compromise and i am using it now.
But.. something else is not clear to me. TGSL is great for coins...small items..perfectly reject unwanted targets etc...etc... But does not have good "depths" on very large objects...like...Fisher 1265 for example.
Let me explain; TGSL is better and more powerfull than 1265 on small coins in soil. Discrimination is also much more accurate than at 1265. But...1265 reacts on large metal plate (20x20) at much more distance in air and soil than TGSl??? How come?
With Sense adjusted to max you can run 1265 to be very sensitive and reactive on larger items. On some objects it can react at more than 1m in air. Other hand TGSL can not?? How come? If we know previously that TGSL successfully detects 1e coin at ...let's say 25cm in soil, while 1265 bairly detect same coin at 15cm in soil (just an example).
Something is missing here? Something i still dont understand and would like to learn. It is almost like TGSL has "limited field" of detection but all items in that field are detected very well. And 1265 has more amplification and can react on larger distances but it is generally weaker at small items in soil, than TGSL... (don't guess me wrong; 1265 is also very good for coins...but not that good as TGSL).
What relations are those? Scoping TX output at both machines i cant see any significant differences (except frequency).
It is like TGSL need more amplification,gain...or what?
Need to act more "wild". At very small and distant targets it tends to produce faint signals. And this is not only the case with my handmades. I had chance to see and test few original Tesoro machines - same case; good but "limited"...
So... any explanations?
I agree, TGS is not easy to improve. Generally i am very satisfied with what i gained so far. TGSL preforms excellent on small coins in ground.
But...main goal here is not to make device and stay satisfied with it!
Right?Main goal for me is to constantly experiment and try to improve it at least a bit. So i did "million" small experiments and mods. Most of those gave no improvements. Very few gave some results. I can name a list of all what i done so far, but no need for that. I focused latelly only on audio stage cose that showed to be weakest part of design. BD140 version gives good compromise and i am using it now.
But.. something else is not clear to me. TGSL is great for coins...small items..perfectly reject unwanted targets etc...etc... But does not have good "depths" on very large objects...like...Fisher 1265 for example.
Let me explain; TGSL is better and more powerfull than 1265 on small coins in soil. Discrimination is also much more accurate than at 1265. But...1265 reacts on large metal plate (20x20) at much more distance in air and soil than TGSl??? How come?
With Sense adjusted to max you can run 1265 to be very sensitive and reactive on larger items. On some objects it can react at more than 1m in air. Other hand TGSL can not?? How come? If we know previously that TGSL successfully detects 1e coin at ...let's say 25cm in soil, while 1265 bairly detect same coin at 15cm in soil (just an example).
Something is missing here? Something i still dont understand and would like to learn. It is almost like TGSL has "limited field" of detection but all items in that field are detected very well. And 1265 has more amplification and can react on larger distances but it is generally weaker at small items in soil, than TGSL... (don't guess me wrong; 1265 is also very good for coins...but not that good as TGSL).
What relations are those? Scoping TX output at both machines i cant see any significant differences (except frequency).
It is like TGSL need more amplification,gain...or what?
Need to act more "wild". At very small and distant targets it tends to produce faint signals. And this is not only the case with my handmades. I had chance to see and test few original Tesoro machines - same case; good but "limited"...
So... any explanations?
However, normally slower filter causes delay, depending on which part of waveform you detect, so if 1265 is actually quick recovery like TGSL, you would expect equal depth with big deep objects.
Could it be coil differences?
I have not yet experimented with size of "integrator" capacitor following the synchronous detector JFETs - sort of a hidden part of the filter. Could make a difference.
I'll say that my Tesoro Compadre often detects big objects (soda can and larger) very deep. I can lift the coil way above the ground - but not a meter, maybe 2/3 meter. I get excited at first, such a nice signal, then raise coil way up -- still beeps, forget it, buried kitchen sink or something!
But strange, sometimes very big coin not register as well as smaller coin or about same - probably because 5.75" coil.Well -- keep testing!
Cheers,
-SB
Comment