I don't have a lot of experience working with oscilloscope, it is strange to me that if I connect the scope with a wire and leave the other end of wire floating in the air, I would see a regular sine signal of frequency 600KHz.
I suspect this is because of the impedance of the oscilloscope, but adding a 50 ohm terminator doesn't fix the problem.
Is that normal ? If it is not normal, how can I fix the problem?
Thank you very much