The results are so clean, that .. maybe.. it would even be possible to look at cable / connector differences?
Here I would like to show some shots - maybe- interesting?
I had cheated a bit. Up above you had seen what it is like when everything is "perfect".
Now I had changed the scope termination to 50ohm. This creates -20% reflection at the "far", oscilloscope end.
On the ART output we still have it's very good output termination, hopefully creating less than a percent reflections, that is, "eating up" the crud coming back to it.
Also, the cable is still that short cable - the consecutive reflections are decreasing down faster.
So, it's still quite a "not bad" situation!
Here it is that fast video cable, with RCA connector at the scope end, and the obligatory rca-bnc converter.
Everything is strongly zoomed in, so as to see the differences. Also, I am looking at the lower, audio range, (0-50kHz),
so lowering the sampling rate, with which also the resolution is decreased, as explained/ had shown earlier.
So, the higher picosec distribution values are a consequence of all these factors together.http://postimage.org/image/9qzw6tus/
Here it is the same setup, with the Belden cable, all 75ohm BNC:http://postimage.org/image/9r6ic7tw/
And here it is the same Belden cable, with a 10dB 75ohm attenuator applied:http://postimage.org/image/9r85vkbo/
I would leave to You the conclusions..