Hi Mauro,

Sorry about the delay. Some workload.

You wrote:

...
unfortunately I do not know the ansver to your question, but I am VERY
interested on this kind of antennas for my 137 and 500KHz rx ..
please, how big are the "probes" ???

Is this antenna also usable for 8KHZ dream bands, or for SAQ Grimeton
reception ??
...

The two "probes" are only 30 cm of length, using 4 mm of insulated wires.

For 137 kHz it should work, but at 500 kHz the common mode ratio will be
less sufficient - according to the datasheet of the INA111.

These input filters are nearly optimal from 10 up to >100 kHz.
For 8 kHz I would suggest increasing the series capacitors from
22 pF up to ~50 pF.

I made screen shots. Will upload them next.

Peter, df3lp