So I made today the wires shortener from the tuning pot, made a PI Filter with two capacitors and 10 Ohm Resistor
and listen two the sound: there was no disturbing noise and only silent clicks hearable,
as I listen and tune and listen the raduino works out, now in the moment there are only bold signs in the headline,
no more frequencies, I think it is better to give up fore the moment.
Many many thinks, but? shit happens ;-(
