Dear @brunorivademar : " These are the true facts ( not " illusions. ) measurements/specs in the 1957 designed 927:
speed unnaccuracy: +,- 0.15%, the swing tell us that the speed unaccuracy in reality is: 0.30% ( the worst I ever seen in any TT. ).
wow an flutter: +,- 0.05% with a swing of: 0.1% ( again the worst I ever seen in any TT. ).
signal to noise ratio: 58db ( again............. ).
as I posted: the 927 was designed for radio stations ..."
Got it?
R.