We have some picotech scopes here. But my wish would be that there is a way without post processing. Of course if it's always the same measurement I could write a script. But it would be very convenient to have a out of the box solution. For me it is not 100% clear why the modern scopes can't measure till 1 mHz. Is it because of the DC stability? Is the 1/f noise is too high?
Thank you for details..
Certainly 100, 200, 500 MHz scope front ends will not be optimized for 1/f noise.
Scopes work with simple principle of getting one long buffer and then applying measurements on it, FFT and all.
On my Picoscope getting 6,1mHz bin width at 200 SPS/s and 16kbins takes 81 seconds for single sweep.
That is still order of magnitude worse than what you need..
It simply is not that practical.