Ivconic's Negative Ion Detector circuit

[goldfinder]

Hi J Player,
the circuit you referenced is the one I built and it works fine for electrostatic fields but is lousy for a strict ion detector as one cannot tell the difference between ions and electrostatic field with it. What is needed is a true ion detector. Now, your mods with the charged antenna might do the trick; however, I doubt it. The FEt can't distinguish.

So this may point to the IVCONC circuit having the same problem since the opamp he is using has a high impedance FET frontend. So maybe we haven't gotten anywhere.

Hello IVCONIC,
What you say on this? Do you have any evidence that your circuit also detects electrostatic fields? I suppose its possible that the antenna will shield out the ES fields and also seperate/filter the ions so only ions get to the center probe antenna. If that is the case I'd go for the J_Player circuit mod. I KNOW that 3819 FET is extremely sensitive. It will detect a flea scratching his ear from 10 feet (haha).

Goldfinder