Did the TDI SL second mod yesterday...

[Orbit]

I tried to modify the high pass filter (470n; 5.6M) by changing the values of R and C, to get better gain, but unfortunately the GB is affected as you mention.
By making a C-bridge (470n), it improves the sensitivity, but again, we affect the GB.
The question is, does anyone know of a mod that solves both problems?
It is worth a try, because the improvement in sensitivity is important.

Thank you, Jose, that means it wasn't just an illusion, it's the truth

[Carl-NC]

I don't understand why shorting C42 would mess up the GB. Whether you remove R75 or not certainly should not matter. There is also a shorting switch (U7d) across R75, it's possible that it will cause problems. Lift pin 10 of U7 to disconnect.

[Jose]

Carl, thanks for responding. Why short circuit C42, it is in order to get more sensitivity to small objects, in fact the mod is not new, it was described by Reg in another forum and I call it high gain mod.
It is true that removing this filter affects GB and noise. It may be that this mod has worked well on some TDIs that include noise reduction mods and the adverse effects were not so noticeable. Here is a link where this topic is discussed.
https://www.detectorprospector.com/f...ment=184818

[Orbit]

My TDI-SL has the same mods as the original SL-TDI, but without the mod that Reg mentions on the link that applies to c42 and r75..And it just so happens that on the table geb works normally and nothing is noticed, however, when I brought the detector out to check on the target I already have in the ground when I wave over the target, the signal drifts to the left and not to the right, just as Eric thought without the added filter the link states in the discussion that the third filter was added due to signal drift, which was later discovered to be signal drift coming from another place ,however, as I mentioned, when I short-circuited the c42, exactly what Eric thought happened, i.e. the target signal drifted it seems to lose stability, that is, it works with a bad geb balance, and only when I reduce the sensitivity by 50 percent does the detector work properly...

[Orbit]

An active clamp seems to affect drift..pin 10 u7 I lifted it is not in contact I removed 5.6m c42 jumped, now TDI works without drift with an 8 inch coil it detects in the ground a small roman follis at 27cm with good signal strength..

[Jose]

Thanks Orbita, I'll try it.