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RE: Water probe: improvements

Original poster: "Denicolai, Marco" <Marco.Denicolai@xxxxxxxxxxx>

Hi Bob,

> I just reread your post and realized you had some
> compensation for input C of 100pf that's huge figure to
> compensate for and the amp may have run out hf gain hence the
> wrong edge height.

The original capacitance of the lower voltage arm of the divider is
about 500 pF. The capacitance of the schottky diodes I added (one
between input and V+, the other between input and V-) is 50 pF. So two
of them makes 100 pF.
I am really not confident the amplifier would last a second without them
if the TC is turned on.

The opamp gain (with my simulations) should go to 0 dB at -100 degrees
at 56 MHz.

> I don't know your circuit but if the comp ration is not
> correct that could be the source of your problem too similar
> if not the same as above.

The "bump" prevents me to compensate precisely at the moment.

Best Regards