I think the problem is because CRT displays didn’t have pixels so the uniform noise which is static was not only uniformely spread in distribution and intensity (i.e. greyscale level) but also had “dots” of all sizes.

Also another possible thing that’s off is the speed at which the noise changes: was it the 25fps refresh rate of a CRT monitor, related to that rate but not necessarily at that rate or did the noise itself had more persistent and less persistent parts?